Parks Victoria Technical Paper Series No. 59
Adaptive Experimental Management of
Foxes
Alan Robley and Andrew Gormley
Arthur Rylah Research Institute for Environmental
Research
John Wright and Illonna Evans
Parks Victoria
December 2008
Parks Victoria Technical Series No. 59
Final Report 2002-2007
EXECUTIVE SUMMARY
Parks Victoria initiated the Fox Adaptive Experimental Management (AEM) project in 2001 in
partnership with the Arthur Rylah Research Institute for Environmental Research (ARIER) to
measure the costs and benefits of a range of fox control strategies and examine the
applicability of AEM for large-scale pest management programs. This final report presents
the results of the implementation of the project.
Major findings of the project relate to differences in the effectiveness of various baiting
strategies. Continuous-annual baiting programs (Coopracambra and
Hattah-Kulkyne
National Parks) showed substantial reduction in bait-take, which has remained low relative to
the free-feed period at the start of the program. Pulsed baiting programs at Wilsons
Promontory National Park and the Grampians have also shown an overall decline in baittake. Seasonal baiting at Little Desert National Park did not show consistent results across
time. Some decline in bait take was observed within some seasons, but this seasonal baiting
program was not able to reduce or maintain a reduced level of bait take or fox activity from
year to year.
The baiting examined in this project relies on a single tactic, 1080 poisoned baits. The
reliance on a single tactic will always have limited success in reducing the target species.
Furthermore, there is evidence indicating that resistance to 1080 can build up over time.
Consideration should be given to alternative tactics to control foxes over large area and long
periods.
Sand plot activity monitoring was established to provide an independent measure of the
change in the fox populations at each of the parks. The number of plots deployed in each
park was limited by the availability of resources. Analysis of sand plot data has revealed that
the level of effort used in this project is unlikely to be able to separate out process and
measurement error from actual changes in fox activity for most parks. The exception to this is
the Grampians, where a clear separation in fox activity between baited and unbaited areas is
apparent. This is mainly due to the greater effort this park was able to expend on sand plot
monitoring. The use of sand plot activity monitoring should be reviewed. Recent work by
ARIER indicates that motion activated cameras may be a cost-effective alternative.
Prey-species monitoring was implemented successfully in all parks and established the
presence of a range of native species likely to benefit from a reduction in fox abundance. A
number of notable fauna records were made through this project, including; establishing the
presence of Long-nosed Potoroo and Southern Brown Bandicoot in Coopracambra National
Park, the first record of Little Pygmy Possum in Little Desert National Park, re-establishing
the presence of Long-nosed Potoroo in the Grampians after nearly 30 years and a range
extension for the Southern Brown Bandicoot at the same park.
Over the duration of the project, no trends were detected in estimates of abundance of native
species. Capture rates at the Grampians, Wilsons Promontory and Coopracambra were all
low making sensible and robust estimations of abundance unreliable. At Little Desert, some
groups of species showed signs of increase on some blocks but there was no overall trend in
the data to suggest a consistent response to fox control. This is not unexpected as there was
no long-term decline in bait take or activity as assessed by sand plot monitoring. Data from
Hattah-Kulkyne are inconclusive due to inconsistencies in delivery across time.
Detecting changes in animal abundance is one of the most common problems facing wildlife
managers. Estimation of actual abundance is usually time consuming and expensive. In this
situation, indices of animal abundance can be used to estimate relative changes in animal
abundance. Since the inception of the fox AEM program, new methods and approaches have
been developed to monitoring and evaluating responses of native species to large-scale
management actions that are aimed at increasing biodiversity.
II
Parks Victoria Technical Series No. 59
Final Report 2002-2007
Two large-scale fox control projects in Victoria, Southern Ark in East Gippsland and Glenelg
Ark in the far south-west of the state, are approaching this issue by looking at changes in site
occupancy of a range of native species. The basic premise is that as predation pressure is
eased by the reduction in fox numbers species that are regulated by predation will increase
in number and therefore sites that were not occupied will become occupied. While not always
directly related to abundance, for rare species changes in occupancy can be related directly
to changes in abundance. It is recommended that this approach be considered for any future
assessment for changes in native fauna resulting from large-scale management action.
Large-scale sustained predator control programs undertaken by government agencies are
common in Australia. However, a common problem is that it is difficult to sustain national,
state or individual operations over long periods of time. Adaptive management may assist in
maintaining pest control operations over a long time frame. It allows managers to coordinate
data collection across different operations to improve the quality of routine procedures and
analyses. By using data to predict consequences of management actions and evaluating
whether those predictions are realised, adaptive management helps ensure business
planning considers the ecology of the systems being managed, rather than being driven by
budget constraints. Adaptive management also decreases uncertainty in complex
management systems or decreases the risk of failure (or unsustainability) by making the
uncertainty more explicit.
This project aimed to test the application of an adaptive experimental management approach
to improve understanding about the management of foxes in parks and reserves across
Victoria. Across the duration of the project, a number of shortcomings not foreseen at the
commencement of the project were identified. This is not surprising given that it is, as far as
we are aware, the first attempt to implement an AEM approach for large-scale pest
management in Australia and certainly Parks Victoria’s first attempt at implementing such an
approach. Despite these shortcomings, we believe the project has yielded a great deal of
information that will assist in improving Parks Victoria’s fox management programs, as well
as giving a better understanding of how an adaptive management approach may be better
implemented in future.
3
Parks Victoria Technical Series No. 59
Final Report 2002-2007
CONTENTS
EXECUTIVE SUMMARY............................................................................................ II
CONTENTS............................................................................................................... IV
INDEX OF FIGURES AND TABLES......................................................................... VI
1 INTRODUCTION ...................................................................................................1
2 METHODS.............................................................................................................3
2.1 Overview ........................................................................................................................ 3
2.2 Study Sites ..................................................................................................................... 3
2.3 Fox Control..................................................................................................................... 3
2.4 Response to Baiting Strategies ...................................................................................... 4
2.4.1 Ground based baiting using sodium monofluorocetate (1080) ..................................................4
2.4.2 Changes in fox activity ...............................................................................................................5
2.5 Associated Change in Native Species ............................................................................ 5
2.5.1 Data Analysis .............................................................................................................................7
2.6 Cost Benefit Analysis...................................................................................................... 8
2.6.1 Costs and benefits of management program .............................................................................8
2.6.1.1 Vehicle Costs .................................................................................................................................. 8
2.6.1.2 Staff Costs ...................................................................................................................................... 9
3 RESULTS .............................................................................................................10
3.1 Fox Control and Monitoring .......................................................................................... 10
3.1.1 Continuous – Annual baiting strategy .......................................................................................10
3.1.1.1 Hattah-Kulkyne (high intensity baiting) and Coopracambra (low intensity baiting) national parks 10
3.1.2 Pulsed Baiting Strategy ............................................................................................................12
3.1.2.1 ilsons Promontory and Grampians National Parks (medium intensity baiting) ............................. 12
3.1.3 Seasonal Baiting Strategy ........................................................................................................15
3.1.3.1 Little Desert and Grampians (perimeter) national parks ................................................................15
3.1.4 Cost Effectiveness of Baiting Strategies ..................................................................................17
3.2 Pattern in Native Species Response ............................................................................ 17
3.2.1 Continuous – Annual baiting strategy .......................................................................................17
3.2.1.1 Hattah-Kulkyne National Park (high baiting intensity) ...................................................................17
3.2.1.2 Coopracambra National Park (low intensity baiting) ......................................................................19
3.2.2 Pulsed Baiting Program ............................................................................................................23
3.2.2.1 Grampians National Park ..............................................................................................................23
3.2.2.2 ilsons Promontory National Park ...................................................................................................27
3.2.3 Seasonal Baiting Strategy ........................................................................................................30
3.2.3.1 Little Desert National Park ............................................................................................................30
4 DISCUSSION ......................................................................................................32
4.1 Effective Baiting Strategies ........................................................................................... 32
4
Parks Victoria Technical Series No. 59
Final Report 2002-2007
4.2 Changes in Native Species........................................................................................... 33
4.3 AEM and Parks Victoria ................................................................................................ 35
5 ACKNOWLEDGMENTS .......................................................................................38
6 REFERENCES .....................................................................................................39
APPENDIX 1 ......................................................................................................... A1.1
A1. Summaries of fox control strategies in each part in the fox AEM project......................A1.1
A1.1 Coopracambra National Park.................................................................................................. A1.1
A1.2 Discovery Bay Coastal Park (Discontinued in 2002) .............................................................. A1.1
A1.3 Grampians National Park........................................................................................................ A1.1
A1.4 Hattah-Kulkyne National Park................................................................................................. A1.2
A1.5 Little Desert National Park ...................................................................................................... A1.2
A1.6 Wilsons Promontory National Park ......................................................................................... A1.2
APPENDIX 2 ......................................................................................................... A2.1
A2. Passive Activity Index Procedure (Sand Plot Monitoring) .............................................A2.1
A2.1 Background ............................................................................................................................. A2.1
A2.2 Method .................................................................................................................................... A2.1
APPENDIX 3 ......................................................................................................... A3.1
A3. Costs of Implementing Fox AEM .............................................................................................. A3.1
APPENDIX 4 ......................................................................................................... A4.1
A4.1. Species within groups captured at Hattah-Kulkyne National Park, 2004-2007 ..................... A4.1
A4.2 Species within faunal groups captured at the Eastern Block, Little Desert National Park, 20042007 ......................................................................................................................................... A4.2
A4.3 Species within faunal groups captured at the Central Block, Little Desert National Park, 20042007 ......................................................................................................................................... A4.3
A4.4 Species within faunal groups captured at the Western Block, Little Desert National Park, 20042007 ......................................................................................................................................... A4.4
5
Parks Victoria Technical Series No. 59
Final Report 2002-2007
INDEX OF FIGURES AND TABLES
FIGURES
Figure 1. Diagrammatic representation of the AEM process ....................................................................2
Figure 2. Percentage daily bait take for Hattah-Kulkyne National Park. Bars are 95% confidence
limits .......................................................................................................................................10
Figure 3. Percentage daily bait take at Coopracambra National Park. Bars are 95% confidence
limits .......................................................................................................................................10
Figure 4. Fox activity for Hattah-Kulkyne National Park. Bars are 95% confidence limits. ....................11
Figure 5. Fox activity for Coopracambra National Park. Bars are 95% confidence limits. .....................11
Figure 6. Percentage daily bait take for Wilsons Promontory National Park. Bars are 95%
confidence limits .....................................................................................................................12
Figure 7. Percentage daily bait take at the Grampians National Park. Bars are 95% confidence
limits .......................................................................................................................................13
Figure 8. Fox activity at Wilsons Promontory National Park. Bars are 95% confidence limits. ..............14
Figure 9. Fox activity at the Grampians National Park. Bars are 95% confidence limits .......................14
Figure 10. Percentage daily bait take for the Eastern Block of the Little Desert National Park.
Bars are 95% confidence limits ..............................................................................................15
Figure 11. Percentage daily bait take for the Eastern Block of the Little Desert National Park.
Bars are 95% confidence limits ..............................................................................................15
Figure 12. Fox activity on the eastern (a), central (b) and western (c) blocks of the Little Desert
National Park. Bars are 95% confidence limits .......................................................................16
Figure 13. Captures per 100 trap nights for each species group on the treatment and niltreatment site at Hattah-Kulkyne National Park. .....................................................................18
Figure 14. Posterior distribution of abundance for each year (2004-2007) for Long-nosed
Potoroo at Coopracambra National Park ................................................................................20
Figure 15. Posterior distributions of abundance for each year (2004-2007) for Southern Brown
Bandicoot at Coopracambra National Park. ...........................................................................21
Figure 16. Posterior distributions of abundance for each year (2004-2007) for Common Brushtailed Possum at Coopracambra National Park .....................................................................23
Figure 17. Posterior distributions of abundance for each year (2004-2007) for Southern Brown
Bandicoot at the Grampians National Park. ...........................................................................24
Figure 18. Posterior distributions of N for each year (2004-2007) for Long-nosed Potoroo at the
Grampians National Park. ......................................................................................................26
Figure 19. Posterior distributions for each year (2004-2007) for Common Brush-tailed Possum
at the Grampians National Park .............................................................................................27
Figure 20. Posterior distributions of abundance for each year (2004-2007) for all areas
combined for Long-nosed Potoroo at Wilsons Promontory National Park. .............................29
Figure 21. Native species response on the Eastern, Central and Western blocks, Little Desert
National Park. .........................................................................................................................31
Figure 22. Number of years sampling needed to detect changes in population growth. .......................34
TABLES
Table 1. Fox control strategies for the Fox AEM project ...........................................................................4
Table 2. Detection techniques used at each park, the number of sites selected and the nominal
target species for each park ......................................................................................................6
Table 3. Overall cost of delivering the Fox AEM program for each strategy. .........................................17
Table 4. Raw capture data for Long-nosed Potoroo at Coopracambra National Park. ..........................19
Table 5. Estimates of abundance (SD) for Long-nosed Potoroo at Coopracambra National Park. .......19
6
Parks Victoria Technical Series No. 59
Final Report 2002-2007
Table 6. Raw capture data for Southern Brown Bandicoot at Coopracambra National Park.
................................................................................................................................................................20
Table 7. Estimates of abundance (SD) for Southern Brown Bandicoot at Coopracambra National
Park ........................................................................................................................................20
Table 8. Raw capture data for Long-nosed Bandicoot at Coopracambra National Park.
................................................................................................................................................................21
Table 9. Estimates of abundance (SD) for Long-nosed Bandicoot at Coopracambra National
Park ........................................................................................................................................22
Table 10. Raw capture data for Common Brush-tailed Possum at Coopracambra National Park
................................................................................................................................................................22
Table 11. Estimates of abundance (SD) for Common Brush-tailed Possum at Coopracambra
National Park ..........................................................................................................................22
Table 12. Raw capture data for Southern Brown Bandicoot at the Grampians National Park.
................................................................................................................................................................24
Table 13. Estimates of abundance (SD) for Southern Brown Bandicoot at the Grampians
National Park. .........................................................................................................................24
Table 14. Raw capture data for Long-nosed Potoroo at the Grampians National Park.
................................................................................................................................................................25
Table 15. Estimates of abundance (SD) for Long-nosed Potoroo at the Grampians National
Park ........................................................................................................................................25
Table 16. Raw capture data for Common Brush-tailed Possum at the Grampians National Park
................................................................................................................................................................26
Table 17. Estimates of abundance (SD) for Common Brush-tailed Possum at the Grampians
National Park. .........................................................................................................................26
Table 18. Raw capture data for Long-nosed Potoroo at Wilsons Promontory National Park.
................................................................................................................................................................27
Table 19. LPC capture-recapture estimates (SD) of abundance for each year (2004-2007) for
Long-nosed Potoroos at Wilsons Promontory National Park. ................................................28
Table 20. Bayesian capture-recapture estimates (SD) of abundance for each year (2004-2007)
for Long-nosed Potoroos at Wilsons Promontory National Park. ...........................................28
Table 21. Raw capture data for Southern Brown Bandicoot at Wilsons Promontory National
Park ........................................................................................................................................29
Table 22. Raw capture data for Common Brush-tailed Possum at Wilsons Promontory National
Park ........................................................................................................................................30
Table 23. Estimates of abundance (SD) for each year (2004-2007) for Common Brush-Tailed
Possum at Sealers Cove, Wilsons Promontory National Park. ..............................................30
Table A3.1. Hattah-Kulkyne: Annual / Intensive Program.................................................................. A3.1
Table A3.2. Coopracambra: Annual / Intensive Program................................................................... A3.1
Table A3.3. Grampians National Park: Pulsed / Moderate Intensity Program ................................... A3.1
Table A3.4. Wilsons Promontory National Park: Pulsed / Moderate Intensity Program .................... A3.2
Table A3.5. Little Desert National Park Eastern Block: Seasonal / Medium Intensity ...................... A3.2
Table A3.6. Little Desert National Park Central Block: Seasonal / Low Intensity Program .............. A3.2
VII
Parks Victoria Technical Series No. 59
Final Report 2002-2007
1 INTRODUCTION
Predation by the red fox (Vulpes vulpes) is a significant issue affecting the conservation of
many species of Australian native fauna with an estimated environmental cost of fox
predation across Australia to be $190 million per annum (McLeod 2004). Predation by the
foxes is listed as a threatening process under the Commonwealth Environment Protection
and Biodiversity Conservation Act 1999 and a potentially threatening process under the
Victorian Flora and Fauna Act 1988. Environmental management agencies across Australia
invest heavily in fox control to protect native fauna populations. Reddiex et al. (2004)
estimated that across Australia $5.3 million is spent per annum on labour costs controlling
foxes. Despite substantial investment in fox control across the country, the effectiveness of
different control strategies in reducing fox abundance and the benefits this has for native
fauna populations are not well understood.
As manager of Victoria’s protected area network, fox control is an important part of Parks
Victoria’s natural values management program. Since 2001, Parks Victoria has typically
implemented fox control programs at 60 – 70 (and up to 104) parks across the state. These
range from programs that treat small areas for a short period of the year through to those
that operate year-round over large areas of the landscape.
In 2001, Parks Victoria initiated a project in partnership with the Arthur Rylah Institute for
Environmental Research (ARIER) to examine the effectiveness and efficiency of different fox
control strategies. The project uses an Adaptive Experimental Management (AEM) approach
(Walters 1997). Adaptive management is an approach that includes scientific methods in the
design, implementation and evaluation of management strategies. It can include the natural
and social sciences, and it recognises the importance of institutional and social structures to
management and policy decisions.
Adaptive Experimental Management considers management actions as experimental
treatments and employs scientific methods such as replication and experimental control. This
allows alternative management strategies to be compared simultaneously (Figure 1). The
use of a modelling framework is central to adaptive management (Walters 1997). Models are
used to explicitly describe components of management and their relationships, to articulate
assumptions and, most importantly, to incorporate specifically the levels and types of
uncertainty in prior knowledge and data collection. The understanding of uncertainty and its
consequences differ greatly between individuals, even at the level of managers and
scientists (Marcott 1998). Mathematical models can include uncertainties and complexities in
a systematic and quantitative way.
The range of sites at which Parks Victoria undertakes fox control and the range of strategies
implemented across these sites provide an opportunity for applying and testing an Adaptive
Experimental Management approach.
1
Parks Victoria Technical Series No. 59
Final Report 2002-2007
Managers formulate competing models of the managementfox density-prey response complex
Different fox management
regimes imposed on a series of sites
Models used to predict effects
of different management regimes
Fox density and prey
response/s monitored
Predictive power of models
judged using monitoring data
Best model/s identified
Best model/s used to refine
management
Improved fox management
Figure 1. Diagrammatic representation of the AEM process.
There are many knowledge gaps surrounding the management of foxes and addressing
these questions is beyond the scope of any one project. The Fox AEM project was
established to:
• Test the applicability of AEM to broad-scale pest management by Parks Victoria
•
•
Examine the effectiveness of different spatial and temporal intensities of baiting on fox
and prey abundance
Evaluate the costs and benefits of each strategy
Some of these issues such as costs and applicability could be examined over a relatively
short-term (2 -3 years). However, examining the response of native fauna populations to fox
control is a critical component of the project. Other studies such as Western Shield (Orell
2004) indicate that prey species responses are likely to be patchy and that it may take at
least four or five years of consistent fox control before a response is detectable. As such, the
Fox AEM project was established to run for an initial five-year period.
As the five-year milestone has been reached, this final report reviews the results of the
project against the questions it was established to address. The report analyses the data
collected on foxes and native species and looks at the relative costs and benefits of different
control strategies. It also identifies and discusses issues experienced in implementing the
AEM approach.
2
Parks Victoria Technical Series No. 59
Final Report 2002-2007
2 METHODS
2.1 Overview
The design of the project was developed through a series of workshops involving staff from
Parks Victoria and ARIER. These workshops identified Parks Victorias objectives for fox
control, the range of control techniques applied and the questions Parks Victoria wished to
address through the fox AEM project. The proceedings of these workshops describe the
process undertaken and the questions identified (Choquenot & Robley 2001a, 2001b).
2.2 Study Sites
The following five parks were involved for the duration of the Fox AEM project:
•
•
Coopracambra National Park
Grampians National Park
•
Hattah-Kulkyne National Park
•
Little Desert National Park
•
•
Wilsons Promontory National Park
Originally, Discovery Bay Coastal Park was included in the project but heavy seas
continually washed out baiting stations and this site was omitted. A subsequent effort to
establish a new site at Eumeralla Coastal Reserve was also abandoned for similar
reasons
2.3 Fox Control
At each of the parks involved in the project, a specific combination of timing and spatial
intensity of fox control using buried sodium monofluoroacetate (1080)-poisoned baits was
implemented (Table 1). Appendix 1 provides details of the original baiting programs for all the
parks involved in the Fox AEM project. The timing of baiting operations has been divided into
three categories:
•
Continuous – annual programs. Baits are checked and replaced every three to four
weeks throughout the year
•
Seasonal programs. Baiting is continuous (i.e. baits checked and replaced every two to
four weeks) within a specific period each year. The period during which baiting occurs is
dictated by a number of factors including the timing of available resources, seasonal
access to areas, or the period a prey species is thought to be most at risk from predation
Pulsed programs. Baiting is continuous for a specific period or ‘pulse’ with a break of
several weeks between ‘pulses’ of baiting
•
The spatial intensity of baiting was measured by the number of baits laid per square
kilometre. Baiting intensity was allocated to one of three arbitrarily defined categories that
reflect the range of control activities in place across the Parks Victoria estate at the beginning
of the Fox AEM project. Spatial intensity categories were:
•
High
> 0.6 baits/km2
•
Medium
0.2 - 0.6 baits/km2
•
Low
< 0.2 baits/km2
3
Parks Victoria Technical Series No. 59
Final Report 2002-2007
Table 1. Fox control strategies for the Fox AEM project
Timing
Intensity
High
Continuous – annual
Seasonal
Hattah-Kulkyne NP
Discovery Bay Coastal
Park
Grampians Red Rock
Pulsed
Eumeralla Coastal Reserve
Little Desert NP - Eastern
Block
Medium
Wilsons Promontory
NP
Grampians NP –
Internal
Coopracambra NP
Low
Little Desert NP - Central
Block
Grampians NP Perimeter
Both Discovery Bay and Eumeralla Coastal Reserves were omitted due to difficulties in
sustaining fox control on highly active beach fronts. Wilsons Promontory was originally split
into three intensities, however, analysis of the data indicated that these sites were not
spatially independent and no difference was detectable between treatments. The Grampians
perimeter baiting program and Red Rock programs ceased in 2003 and internal pulsed
program began.
Prior to the commencement of the Fox AEM project, the focus of fox baiting at the
Grampians National Park was the Brush-tailed Rock-wallaby (Petrogale penicillata) colony at
Red Rock (the last individual from this colony was removed into captivity in 1999 although
works are underway to prepare for a reintroduction), Heath Mouse (Pseudomys shortridgei)
and Smoky Mouse; (Pseudomys fumeus). Additionally, there was extensive baiting as part of
Good Neighbour programs on the boundary of the park. The Brush-tailed Rock-wallaby
baiting program was annual. The Good Neighbour program, which ran around the perimeter
of the Park, was a seasonal program operating between February and June.
In 2003, two years after the AEM project began; the perimeter program was reviewed and
assessed as ineffective. Consequently, the whole baiting program at the Grampians was
redesigned as a pulsed program covering the central section of the park, incorporating the
former Red Rock (Brush-tailed Rock-wallaby) baiting program.
The new baiting program runs for four pulses per year, each pulse lasting nine weeks with a
four-week break between pulses. In 2005/06 the Mt Lubra fire resulted in this program being
altered to allow for a single spring through to the end of summer baiting, with the pulsed
program recommencing in autumn 2006.
The Western Block Little Desert National Park and approximately 20,000 ha (or 42% of the
park area) of Hattah-Kulkyne National Park were left unbaited as control. Similarly, although
the pulsed baiting program at the Grampians National Park covers much of the park area,
there are unbaited areas that serve as a control at this park.
2.4 Response to Baiting Strategies
2.4.1 Ground based baiting using sodium monofluorocetate (1080)
The percentage of baits taken over time is often used to measure the effectiveness of a
control program. Bait take is calculated by dividing the number of baits taken by the number
of baits available and is standardised by the number of days bait is available. This allows for
the fact that baiting times can vary from and within site. The advantage of using percentage
bait-take is in its operational efficiency; it is simple to calculate and data are collected in the
4
Parks Victoria Technical Series No. 59
Final Report 2002-2007
course of implementing the control program (field staff are regularly in the field to replace
baits and are required to report on bait take as a part of the label conditions for using 1080
baits). This measure is particularly useful where there has been a period of free feeding prior
to fox control operations (Saunders et al. 1995).
For parks that were able to implement a free feeding period (Coopracambra and HattahKulkyne National Parks), the effectiveness of the initial knockdown period was analysed by
comparing the difference between indices recorded before (i.e., during the free feed period)
and around one month after poison baiting had commenced. This was assumed to quantify
the immediate effect of 1080 poisoning on fox populations. For parks where free feeding was
not implemented, temporal trends in bait-take are examined.
2.4.2 Changes in fox activity
To offset the analytical difficulties associated with potential caching and multiple bait take, a
second monitoring technique was also used. This technique, known as Passive Activity
Indexing (Sand Plot Monitoring), has been applied more recently to detect changes in
relative abundance (Allen et al. 1996; Mahon et al. 1998; Engeman et al. 2000). See
Appendix 2 for operational details.
This technique provides an independent measure of changes in fox activity, which is
assumed to reflect changes in underlying abundance. However, a number of factors may
influence the precision of this technique. These include:
•
•
Increases in fox activity as a result of the management operation
The reliance of target animals on vehicle tracks for movement
•
The serial correlation resulting from the non-independence of sand plots and the number
of days plots are operated
•
The number of sand plots used
It also requires additional effort and resources to be allocated over and above the poisoning
operation.
A benefit of this approach is that it overcomes the potential problems associated with bait
take, i.e. caching and neophobia, and can provide additional information on the presence of
other species.
For the Fox AEM project, activity was measured using track counts on sand-plots distributed
at a density of one plot per kilometre, with five plots per transect. The number of transects
within each park varied depending on the size of the park, with a minimum of seven transects
per park. Monitoring is undertaken for three consecutive nights, allowing for a calculation of
variance about the activity index, which provides a measure of accuracy.
A comparison of fox activity between treated and non-treated monitoring areas provides
direct estimates of the efficacy of the management program. Comparison of activity between
the treated and non-treated monitoring areas during the initial knockdown phase requires
establishment of sand plots prior to undertaking poisoned baiting.
To assess levels of activity the proportion of plots with fox sign were recorded over a
consecutive three-day period. The 95% confidence limits around the proportion of sand plots
with activity were calculated using the formulae in (Zar 1999). Non-overlapping confidence
limits were taken to indicate a significant difference in activity.
2.5 Associated Change in Native Species
While a range of native species are assumed to benefit from the intensive suppression of fox
activity, target species and groups were selected for monitoring to examine the effectiveness
of the different control strategies used in this project (Table 2). Long-nosed Potoroo
(Potorous tridactylus) and Southern Brown Bandicoot (Isoodon obesulus), were selected for
5
Parks Victoria Technical Series No. 59
Final Report 2002-2007
monitoring at Wilsons Promontory, Coopracambra and Grampians national parks. At the
Grampians, Heath Mouse (Pseudomys shortridgei) and Smoky Mouse (Pseudomys fumeus)
were also selected as target species. Long-nosed Bandicoot (Perameles nasuta) and
Ringtail Possum (Pseudocheirus peregrinus) were selected as additional targets at
Coopracambra. At Little Desert and Hattah-Kulkyne National Parks, herpetofauna were
targeted. Herpetofauna were grouped as follows: Agamids (dragons) Gekkonids (geckos)
Pygopodids (legless lizards) Scincids (skinks) and snakes (families were grouped into one
class) to make summarising the data easier.
A set of monitoring protocols for the target species was developed (Robley & Choquenot
2002) and methods used are summarised in Table 2. A pilot study in the first year of the
project estimated that seven trap sites operated over two sampling sessions each in latespring to early-summer would enable detection of a doubling of the population of target
native fauna species over a three to five year period with 85% confidence that a change has
taken place. It is important to note that these protocols only allow examination of whether
there are associations between particular fox control strategies and prey response, not
causal relationships.
Table 2. Detection techniques used at each park, the number of sites selected and the nominal target
species for each park
Park
Detection
Technique
Number of trap
sites
Target Species
Hattah Kulkyne NP
Pitfall bucket traps
14 (7 treatment, 7
non-treatment)
Mallee Ningaui (Ningaui
yvonnae)
30 buckets / site
Mitchell’s Hopping Mouse
(Notomys mitchellii)
Variety of herptofauna
Little Desert NP
Pitfall bucket traps
21 (7 in each of
the three blocks)
Silky Mouse (Psuedomys
apodemoides)
30 buckets / site
Western Pygmy Possum
(Cercartetus concinnus)
Variety of herptofauna
Grampians NP
Elliott traps
4 x 30 traps / site
Long-nosed Potoroo
Cage traps
7 x 30 traps / site
Southern Brown Bandicoot
Smoky Mouse
Heath Mouse
Wilsons Promontory NP
Cage traps
7 x 30 traps / site
Long-nosed Potoroo
Southern Brown Bandicoot
Coopracambra NP
Cage traps
7 x 30 traps / site
Long-nosed Bandicoot
Ringtail Possum
Long-nosed Potoroo
Southern Brown Bandicoot
Sites for native species response monitoring within each park were selected on the basis of
either records in the Atlas of Victorian Wildlife, habitat suitability based on published
descriptions, local knowledge provided by Parks Victoria staff, or a combination of these
factors.
In all cases, captured mammals were weighed and sexed. Medium-sized mammals (i.e.
bandicoots, possums and potoroos) were marked with passive implant transponders (PIT6
Parks Victoria Technical Series No. 59
Final Report 2002-2007
tags). Each transponder has an individual alphanumeric code to allow individual capture
histories to be determined. Small mammals had a small section of outer coat fur clipped and
the location on the body noted to enable recaptures to be identified and facilitate data
analysis. Reptiles and amphibians were marked temporarily with a small spot of correction
fluid.
2.5.1 Data Analysis
For mammal species at the Grampians, Wilsons Promontory and Coopracambra National
Parks, we estimated abundance (N) using capture-recapture data analysis methods. Each
year was split into two sessions, and the data summarised to show; n1 the number of
individuals captured in session 1, n2 the number of individuals captured in session 2, m2 the
number of previously captured individuals at session 2, and u. the total number of individuals
captured. Annual abundances were estimated using two methods.
Firstly, Chapman’s modification of the Lincoln-Peterson estimator denoted LPC (Manning et
al. 1995). This method is commonly used and has the advantage of being easy to calculate.
This gives point estimates of abundance and a standard error. The formula (1) is:
N =((n1+1)(n2+1)
(m2+1))-1
(1)
The variance of N is given by:
var(N) =[(n1+1)(n2+1)(n1-m2)(n2-m2)]
[(m2+1)2(m2+2)]
(2)
There are two important consequences of using this formulation. In cases where n2 = m2, (all
of the captures in period 2 are previously marked animals) the abundance is estimated to be
n1 with var(N)=0. In cases where n1 = m2 (all of the animals captured in period 1 are
recaptured in period 2), the abundance is estimated to be n2 with var(N)=0. In both of these
cases the estimate of var(N) is unrealistic.
The second approach adopted was the Bayesian version of the equivalent likelihood based
model (Wade 2000; Ellison 2004). This method enables better representation of uncertainty.
Bayesian methods require a prior distribution for abundance (N) representing the probability
that abundance is a particular value. The prior is combined with the likelihood to obtain
posterior probabilities of abundance. Our choice of prior distribution for abundance specified
that the starting abundance was likely to be between 0 and 50, but allows for the probability
that it may have been greater.
There are some important consequences for using a Bayesian method. In cases with very
few sightings, or no recaptures of marked animals (i.e. m2 = 0), posterior distributions for N
were dominated by the prior distribution, are highly skewed and must be viewed with caution.
A posterior distribution that is similar to the prior suggests better data are required. Both
methods enable estimation of capture probability, i.e. the chance that an individual will be
captured if it is present, which will vary each year.
Where animals could not be individually marked, Hattah-Kulkyne and Little Desert National
Park, we computed catch per unit effort (CPUE) as the total number of captures per 100 trapnights. Where trapping frequencies were greater than 0.2, we used a frequency-density
transformation to convert capture rate into a density estimate (Caughley 1977). Both Hattah7
Parks Victoria Technical Series No. 59
Final Report 2002-2007
Kulkyne and Little Desert had the advantage of non-treated (i.e unbaited) sites. We
compared the capture rates on treated sites to the respective non-treated sites. If there was
a general response to fox control a difference in the trend between the treatment and nontreatment sites should be evident.
2.6 Cost Benefit Analysis
Often program managers are called on to evaluate their programs and activities to ensure
that expenditure by the government represents value for money. Cost-benefit analysis (CBA)
is a method of quantitative evaluation, which is widely used to assess both existing and
proposed policies, projects and programs. An important aspect of the fox adaptive
experimental management program is to undertake an objective review and assessment of
the management program in order to aid judgements about its appropriateness, efficiency
and effectiveness.
CBA attempts as far as possible to put all costs and benefits arising from a project into
monetary terms, to enable sensible comparisons between alternatives. However, there are
problems in undertaking a cost-benefit analysis of fox predation and control. Providing clear
data on the adverse impact that foxes have on native species is difficult as most fox control
programs manage to reduce predation on native species, at least to some extent, therefore
making it difficult to estimate the effects of removing control. Previous experience of
predation, surplus killing in particular, will result in managers being unwilling to countenance
uncontrolled fox populations. Thus, figures on losses or damage can be misleading, rarely
reflecting the potential impact that could arise in the absence of any control work.
As with most vertebrate pests, there is a relationship between the abundance of foxes and
the level of damage they cause. This relationship is called the damage function (Hone,
1994). Most fox control programs and economic assessments of control work are undertaken
on the presumption that the damage function is linear. That is, an incremental decrease in
the abundance of foxes will result in a proportional decrease in predation.
What this means in practical terms is that it is very difficult to predict the return expected for
different levels of control effort and impossible to calculate the break even point below which
it is uneconomic to control foxes. The ability of foxes to surplus kill means that the number of
individuals preyed upon does not vary predictably with the numbers of foxes present. One
fox may be responsible for a large number of deaths. It is therefore difficult to make
management decisions about the required effort and hence, required budget for adequate
fox control.
2.6.1 Costs and benefits of management program
Virtually all of the costs in delivering the control strategies used in the Fox AEM project are
vehicle costs and staff costs. Parks Victoria staff involved in managing and implementing the
Fox AEM program in Victoria have supplied the information provided in this section.
2.6.1.1 Vehicle Costs
The vehicle costs for implementing fox control were estimated as follows:
For each park, an estimate of the total running cost per kilometre for the vehicle used at that
park was obtained from the Royal Automobile Club of Victoria website (www.racv.com.au).
This was multiplied by the number of kilometres driven per annum to implement fox control.
Costs were then divided by the area baited to estimate the cost per hectare for vehicle use to
deliver that particular strategy. The same approach was used to estimate vehicle costs for
sand pad monitoring.
8
Parks Victoria Technical Series No. 59
Final Report 2002-2007
2.6.1.2 Staff Costs
The staff involved in the implementation of the fox AEM project span a range of employment
levels. To enable direct comparison of each strategy, we used the typical salary level of staff
involved in fox control across the state and added 26% to allow for overheads including
insurance and superannuation. This does not include costs of provision of workspace,
uniform, or computers as estimates of these were not available. We then divided this by the
number of working days per annum and multiplied the result by the number of days required
to deliver fox control at a given park. This was then divided by the area baited to estimate the
cost per hectare for staff to deliver that particular strategy. The same method was used to
estimate staff costs for sand pad monitoring.
At some parks, some aspects of the control and sand pad monitoring programs were
delivered by external contractors. For these parks, the number of contractor days required to
deliver these tasks was determined and costs estimated assuming they had been delivered
by Parks Victoria staff. This was to enable comparison of different control strategies without
the confounding effect of different costings for different delivery mechanisms.
9
Parks Victoria Technical Series No. 59
Final Report 2002-2007
3 RESULTS
3.1 Fox Control and Monitoring
3.1.1 Continuous – Annual baiting strategy
3.1.1.1 Hattah-Kulkyne (high intensity baiting) and Coopracambra (low intensity
baiting) national parks
3.1.1.1.1 Bait take
At both Hattah-Kulkyne and Coopracambra national parks, bait take following the
commencement of poisoned baiting remained lower than during the freed feed periods
(Figure 2 and 3). Mean daily percentage bait take at Hattah-Kulkyne during the free feed
period was 5.52 ± 95%CI1.23. For the period following the commencement of poisoned
baiting it was 37% lower at 3.44 ± 95%CI 0.16. Mean daily percentage bait take during the
free feed period at Coopracambra was 27.5 ± 95%CI 4.1 and for the poisoning period was
35% lower at 17.9 ± 95%CI 1.4.
12.0
% Daily bait take
10.0
8.0
6.0
4.0
2.0
May-06
Feb-06
Nov-05
Aug-05
Feb-05
May-05
Nov-04
Aug-04
Feb-04
May-04
Nov-03
Aug-03
May-03
Feb-03
Aug-02
Nov-02
May-02
Feb-02
0.0
Figure 2. Percentage daily bait take for Hattah-Kulkyne National Park. Bars are 95% confidence limits.
% Daily bait take
6.0
4.0
2.0
Dec-05
Sep-05
Jun-05
Mar-05
Dec-04
Sep-04
Jun-04
Mar-04
Dec-03
Sep-03
Jun-03
Mar-03
Dec-02
Sep-02
Jun-02
Mar-02
Dec-01
0.0
Figure 3. Percentage daily bait take at Coopracambra National Park. Bars are 95% confidence limits.
10
Parks Victoria Technical Series No. 59
Final Report 2002-2007
3.1.1.1.2 Fox activity (sand plots)
At Hattah-Kulkyne National Park, fox activity in the baited area decreased markedly (89%)
after the poison baiting program began in late March 2002 and remained lower than during
the free feed period (Figure 4). On average the proportion of sand plots with fox sign during
the free feed period on the treatment site was 0.38 ± 95%CI 0.1 to 0.09 and during the
poisoning period it was 0.11 ± 95%CI 0.07 to 0.05, a difference of 72%. Activity on the
unbaited site also declined significantly immediately following the commencement of the
poisoning program.
Figure 4. Fox activity for Hattah-Kulkyne National Park. Bars are 95% confidence limits.
The proportion of sand plots with fox sign at Coopracambra declined from and average of
0.30 ± 95%CI 0.8 – 0.7 to an average of 0.14 ± 95%CI 0.7 to 0.6, a decrease of 53% (Figure
5). However, activity was variable and of the 10 sampling periods since poison baiting began;
activity was lower than during the pre-poisoning period only 4 times. This variability
confounds the interpretation of the impact the poisoning program has had on the level of fox
activity. The lack of an unbaited control site at Coopracambra also limits our ability to
interpret these data.
Figure 5. Fox activity for Coopracambra National Park. Bars are 95% confidence limits.
11
Parks Victoria Technical Series No. 59
Final Report 2002-2007
3.1.2 Pulsed Baiting Strategy
3.1.2.1 Wilsons Promontory and Grampians National Parks (medium intensity
baiting)
3.1.2.1.1 Bait take
The Wilsons Promontory baiting program was established with different intensities of baiting
applied in three areas of the park. There was a brief period of free feeding and little baiting
had been undertaken in the park prior to this programs inception.
Analysis undertaken in 2003-2004 (see Robley & Wright 2004) revealed that the variation in
bait take in each of the three nominal treatment areas was such that no difference could be
detected. Thus, we have combined data for the three areas and averaged the percentage
bait-take, to look at the overall trend (Figure 6). Bait take during the brief free feed period
was higher than that following the commencement of poison baiting. During the free feed
period, daily percentage bait take averaged 23% ± SD 19 while for the combined poison
period it was 47.7% lower at 8.2% ± SD 4.7.
30
% Daily bait take
25
20
15
10
5
Mar-06
Nov-05
Jul-05
Mar-05
Nov-04
Jul-04
Mar-04
Oct-03
Jul-03
Feb-03
Oct-02
Aug-02
Apr-02
Nov-01
Aug-01
Apr-01
0
Figure 6. Percentage daily bait take for Wilsons Promontory National Park. Bars are 95% confidence
limits.
The pulsed baiting program at the Grampians National Park differs from that at Wilsons
Promontory in that it began in 2003 and there was no free feed period prior to the
commencement of the pulsed baiting program at this park. As such, it is not possible to
examine the initial knockdown by this program. Following the commencement of the pulsed
program, bait take declined relative to that detected through the previous perimeter program.
However, such comparison must be done with caution as the spatial and temporal
arrangements of the two programs differ. Since the commencement of the pulsed program,
bait take has remained relatively stable, at an average level of 10% ± SD 4.0 (Figure 7).
12
Parks Victoria Technical Series No. 59
Final Report 2002-2007
20
% Daily bait tak
15
10
5
0
Spr-03 Sum 03 Aut-04 Spr-04 Sum-04 Aut-05 Win-05 Spr-05 Sum-05 Aut-06
Figure 7. Percentage daily bait take at the Grampians National Park. Bars are 95% confidence limits.
The pattern of peaks in summer/autumn coincide with a time of year when young foxes are in
the population and likely to be on the move. The low points coincide with a time when pups
would be in the den and vixens less likely to be hunting widely. This has implications for the
timing of baiting programs that rely on the road network.
3.1.2.1.2 Fox activity (sand plots)
Activity monitoring at Wilsons Promontory National Park was not implemented until the
beginning of the fourth poison baiting pulse (in April 2002). This was due to delays in getting
the sand required for construction of sand plots certified weed and fungus free, weather, staff
rostering and budgets. This restricts our capacity to investigate the broad effect of the fox
control program on fox activity levels, as by the time activity monitoring had been put in
place, fox abundance had declined, as suggested by the rapid decline in bait-take. However,
data from sand plots show a relatively stable level of fox activity across time, consistent with
bait take data over the same period (Figure 8).
13
Parks Victoria Technical Series No. 59
Final Report 2002-2007
0.35
0.30
Activity index
0.25
0.20
0.15
0.10
0.05
Mar-02
Jun-02
Sep-02
Dec-02
Mar-03
Jun-03
Sep-03
Dec-03
Mar-04
Jun-04
Sep-04
Dec-04
Mar-05
Jun-05
Sep-05
Dec-05
Mar-06
Jun-06
Sep-06
Dec-06
Mar-07
Jun-07
Sep-07
Dec-07
0.00
Figure 8. Fox activity at Wilsons Promontory National Park. Bars are 95% confidence limits.
In the Grampians, activity monitoring was redesigned prior to the commencement of the
pulsed baiting program. Of the 16 sand plots transects established in the Grampians, seven
are located inside the baited area, four are on the boundary of the baited and unbaited area,
and five are located outside the baited area. Transects on the edge of the baited and
unbaited area were treated as part of the baited area for the purpose of analysis.
The initial monitoring session for the sand-plot-monitoring program was undertaken in
December 2003, and coincides approximately with the summer 2003 baiting pulse. At the
commencement of the pulsed baiting program, there was no difference in fox activity in
baited and unbaited areas (Figure 9). Across time, however, the levels of activity diverged,
with the separation of the 95% confidence limits from June 2005 onwards indicating a
significant difference in the level of fox activity between the baited and unbaited areas of the
park.
1.0
Baited
Unbaited
Activity Index
0.8
0.6
0.4
0.2
Figure 9. Fox activity at the Grampians National Park. Bars are 95% confidence limits.
14
Aug-06
Jun-06
Apr-06
Feb-06
Dec-05
Oct-05
Aug-05
Jun-05
Apr-05
Feb-05
Dec-04
Oct-04
Aug-04
Jun-04
Apr-04
Feb-04
Dec-03
0.0
Parks Victoria Technical Series No. 59
Final Report 2002-2007
3.1.3 Seasonal Baiting Strategy
3.1.3.1 Little Desert and Grampians (perimeter) national parks
3.1.3.1.1 Bait take
At Little Desert National Park, baiting was applied at different intensities in the Central and
Eastern Blocks of the park, with the Western Block acting as a nil-treatment control site. It
was not possible to implement a free feeding period, as a baiting program was under way at
this park prior to the commencement of the Fox AEM project.
We analysed the pattern in percentage daily bait take across the five years (2001-2002,
2002-2003, 2003-2004, 2004-2005, and 2005-2006) for each treatment block (Eastern and
Central) separately (Figures 10 & 11). Across the duration of the Fox AEM project, there has
been no decline in the overall percentage bait take on either block.
5.0
% Daily bait take
4.0
3.0
2.0
1.0
0.0
01/02
02/03
03/04
04/05
05/06
Figure 10. Percentage daily bait take for the Eastern Block of the Little Desert National Park. Bars are
95% confidence limits.
5.0
% Daily bait take
4.0
3.0
2.0
1.0
0.0
01/02
02/03
03/04
04/05
05/06
Figure 11. Percentage daily bait take for the Eastern Block of the Little Desert National Park. Bars are
95% confidence limits.
The perimeter baiting program at the Grampians began in 1997, prior to the commencement
of the Fox AEM project. There was no consistent decline in bait take detected across the
time that this program operated (see Robley & Wright 2003). The only years between which
a significant difference in bait take was detected were 1998 and 2000.
15
Parks Victoria Technical Series No. 59
3.1.3.1.2 Fox activity (sand plots)
Final Report 2002-2007
There was no detectable difference in the proportion of sand plots with fox signs between
years or among the eastern (a), central (b) or western (c) blocks in the Little Desert (Figure
12).
1.0
0.8
0.5
Feb-02
Apr-02
Jun-02
Aug-02
Oct-02
Dec-02
Feb-03
Apr-03
Jun-03
Aug-03
Oct-03
Dec-03
Feb-04
Apr-04
Jun-04
Aug-04
Oct-04
Dec-04
Feb-05
Apr-05
Jun-05
Aug-05
Oct-05
Dec-05
Feb-06
Apr-06
Jun-06
0.3
0.0
1.0
0.8
0.5
0.3
0.0
Jan-02
Mar-02
May-02
Jul-02
Sep-02
Nov-02
Jan-03
Mar-03
May-03
Jul-03
Sep-03
Nov-03
Jan-04
Mar-04
May-04
Jul-04
Sep-04
Nov-04
Jan-05
Mar-05
May-05
Jul-05
Sep-05
Nov-05
Jan-06
Mar-06
May-06
a)
b)
c)
Activity Index
Activity Index
1.0
0.8
0.5
Nov-01
Jan-02
Mar-02
May-02
Jul-02
Sep-02
Nov-02
Jan-03
Mar-03
May-03
Jul-03
Sep-03
Nov-03
Jan-04
Mar-04
May-04
Jul-04
Sep-04
Nov-04
Jan-05
Mar-05
May-05
Jul-05
Sep-05
Nov-05
Jan-06
Mar-06
May-06
0.3
0.0
16
Figure 12. Fox activity on the eastern (a), central (b) and western (c) blocks of the Little Desert
National Park. Bars are 95% confidence limits.
Activity Index
3.1.4 Cost Effectiveness of Baiting Strategies
An assessment of the cost effectiveness of the AEM strategies is complicated by the varied
size of each park, the assessment of the effective area treated and the responses of each
monitoring program. See Appendix 3 for detailed costing per park. All continuous and pulsed
programs showed a decline in fox activity as indicated by bait-take. Costs to implement an
annual program were similar to those for implementing a pulsed program (Table 3). Bait take
was lower at Hattah-Kulkyne (annual) and the Grampians (pulsed) than at Coopracambra
(annual) or Wilsons Promontory (pulsed), however direct comparisons of bait-take among
sites are misleading as the relationships between bait-take and fox abundance and how this
varies among different habitats are not well-understood.
The results relating to the effectiveness of seasonal programs are clearer. While such
programs are the least costly to implement, there was no sign that fox bait take or activity
declined across time at either Little Desert or the Grampians (former perimeter program),
neither was there any difference in fox activity between the baited blocks and the unbaited
block at Little Desert.
As a proportion of the overall budget for each strategy, the fox activity monitoring component
of the Fox AEM baiting strategies was greatest for seasonal programs (Little Desert),
accounting for around half of the costs and least for pulsed programs, accounting for around
one third of the cost. On average the sand plot activity monitoring was around 40% of the
overall cost of implementing a strategy.
Table 3. Overall cost of delivering the Fox AEM program for each strategy.
Details of the costs of implementing each of the Fox AEM strategies are provided in
Appendix 3.
Park
Baiting Strategy
Estimated
area
treated
(ha)
Fox Control
($/ha)
Activity
Monitoring
($/ha)
Total
($/ha)
Hattah-Kulkyne
Continuous-High
28 800
0.89
0.59
1.48
Coopracambra
Continuous-Low
38 800
0.60
0.42
1.02
Grampians
Pulsed-Medium
72 520
1.10
0.51
1.61
Wilsons Promontory
Pulsed-Medium
36 000
0.75
0.38
1.13
Little Desert
Seasonal-Low
47 600
0.22
0.29
0.51
Little Desert
Seasonal-High
45 500
0.29
0.24
0.53
3.2 Pattern in Native Species Response
3.2.1 Continuous – Annual baiting strategy
3.2.1.1 Hattah-Kulkyne National Park (high baiting intensity)
Thirty seven species of fauna were captured at Hattah-Kulkyne National Park between 20032005 (Appendix 4). We plotted the captures per 100 trap nights for each group of species for
the treatment and nil-treatment sites (Figure 13). Native species response data were not
collected after 2005 due to local logistics issues.
Capture rates per 100 trap nights were below 0.2, in which case the index is almost linear on
density, so no transformations were necessary (Caughley 1977). Captures tended to be
17
repeated at specific sites within the park, resulting in insufficient data to examine differences
in relative abundance of any species that appeared to be significantly separated among
years of this study.
NT Amphibians
0.8
T Amphibians
0.6
0.4
0.2
0.0
Sum-03
Spr-04
6.0
4.0
2.0
0.0
Sum-03
Spr-04
1.2
T Lizards
0.8
0.4
0.0
Spr-04
1.0
0.5
0.0
Spr-04
8.0
T Geckos
4.0
2.0
0.0
Sum-03
Spr-04
2.0
NT Mammals
T Mammals
1.5
1.0
0.5
4.0
Captures/100 trap nights
Captures/100 trap nights
Sum-03
8.0
6.0
4.0
2.0
NT Skinks
T Skinks
0.0
Sum-03
Spr-04
Spr-05
0.0
Spr-05
10.0
Spr-05
NT Geckos
6.0
Spr-05
NT Lizards
Sum-03
1.5
Sum-03
NT Dragons
T Dragons
NT Blind Snakes
T Blind Snakes
2.0
Spr-05
Captures/100 trap nights
Captures/100 trap nights
8.0
Captures/100 trap nights
Captures/100 trap nights
2.5
1.0
Captures/100 trap nights
Captures/100 trap nights
There was no clear trend in separation between the treatment and nil-treatment sites for any
of the groups of species recorded at Hattah-Kulkyne. While capture rates were high on the
treated sites for mammals and blind snakes capture rates had also increased on the niltreatment site, suggesting either that the baited and non-baited areas were not independent
with respect to fox activity or that other processes were driving the change in capture rate.
Spr-05
3.0
Spr-04
Spr-05
T Snakes
NT Snakes
2.0
1.0
0.0
Sum-03
Spr-04
Spr-05
Figure 13. Captures per 100 trap nights for each species group on the treatment and nil-treatment site
at Hattah-Kulkyne National Park.
18
3.2.1.2 Coopracambra National Park (low intensity baiting)
Nine mammal species were captured at Coopracambra, four of which were the target
species, i.e., Southern Brown Bandicoot, Long-nosed Bandicoot, Long-nosed Potoroo and
the Common Brush-tailed Possum (Trichosurus vulpecular). Bush Rat (Rattus fuscipes),
Swamp Rat (Rattus lutreolus), Sugar Glider (Petaurus breviceps), Ringtail Possum and
European Rabbit (Oryctolagus cuniculis) were also recorded.
In August and September 2005, prey species monitoring was done by the Southern Ark
group of DSE and there was some inconsistency with monitoring protocols established for
the Fox AEM project in that not all species captured in this year were recorded, nor was trap
status recorded. This group only recorded captures of three species; Southern Brown
Bandicoot, Long-nosed Potoroo and Long-nosed Bandicoot.
3.2.1.2.1 Long-nosed Potoroo
The total number of individuals captured over the period 2004 to 2007 was 21. The raw
capture data are shown in Table 4.
Table 4. Raw capture data for Long-nosed Potoroo at Coopracambra National Park.
n1 = the number of individuals captured in session 1; n2 = the number of individuals
captured in session 2; m2 = the number of previously captured individuals at session 2; u.
= the total number of individuals captured.
Year
n1
n2
m2
u.
2004
5
7
4
8
2005
3
6
3
6
2006
3
7
2
8
2007
5
7
4
8
Estimates of abundance using the modified Lincoln-Peterson (LPc) method and the Bayesian
method are presented in Table 5. Both estimates indicate no trend in population trajectory
over the four years.
Table 5. Estimates of abundance (SD) for Long-nosed Potoroo at Coopracambra National Park.
Year
LPc
Bayesian
2004
8.6 (1.0)
9 (2.1)
2005
6.0 (0)
7 (2.1)
2006
9.7 (2.1)
11 (3.8)
2007
8.6 (1.0)
9 (2.1)
The posterior estimates of abundance for each year are shown in Figure 14. These figures
show the probability of actual abundance. For example in 2004 the point estimate was 9 (2.1;
Table 5), however the actually abundance could have been between 8 and 21 (Figure 14),
but was most likely 9. In subsequent years there was most likely no change in Long-nosed
Potoroo captures as the long tails of these distributions overlap.
19
0.4
0.3
0.2
0.1
0
0
5
10
15 20 25 30
Estimate of N
35
0
40
2006
0.16
0.14
0.12
0.1
0.08
0.06
0.04
0.02
0
Probability
Probability
2005
0.5
Probability
Probability
2004
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
0
5
10
15
20
25
30
35
40
5
10
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
30
35
40
15 20 25 30
Estimate of N
35
40
2007
0
Estimate of N
15 20 25
Estimate of N
5
10
Figure 14. Posterior distribution of abundance for each year (2004-2007) for Long-nosed Potoroo at
Coopracambra National Park
3.2.1.2.2 Southern Brown Bandicoot
The total number of individuals captured over the period 2004 to 2007 was 17. The raw
capture data are shown in Table 6.
Table 6. Raw capture data for Southern Brown Bandicoot at Coopracambra National Park.
n1 = the number of individuals captured in session 1; n2 = the number of individuals
captured in session 2; m2 = the number of previously captured individuals at session 2; u.
= the total number of individuals captured
Year
n1
n2
m2
u.
2004
2
7
2
7
2005
2
5
1
6
2006
2
4
2
4
2007
2
4
2
4
Estimates of abundance using the modified Lincoln-Peterson (LPc) method and the Bayesian
method are presented in Table 7. Estimates need to be viewed with caution due to the
sparseness of the capture and recapture data. The LPc estimate suggests a decline in
abundance from 2006, however, the Bayesian estimate indicates the population was stable.
Table 7. Estimates of abundance (SD) for Southern Brown Bandicoot at Coopracambra National Park.
Year
LPC
Bayesian
2004
7 (0)
9 (2.6)
2005
8 (2.5)
8 (2.4)
2006
4 (0)
6 (2.0)
2007
4 (0)
6 (2.0)
20
The posterior densities of abundance for each year are shown in Figure 15. While the point
estimates decline from 9 to 6, the posterior density estimates indicate that actual abundance
is unlikely to have changed.
2004
0.25
0.2
Probability
Probability
0.2
0.15
0.1
0.05
0.15
0.1
0.05
0
0
0
5
10
15 20 25 30
Estimate of N
35
40
0
2006
0.3
5
10
15 20 25 30
Estimate of N
35
40
35
40
2007
0.3
0.25
0.25
Probability
Probability
2005
0.25
0.2
0.15
0.1
0.2
0.15
0.1
0.05
0.05
0
0
0
5
10
15 20 25 30
Estimate of N
35
0
40
5
10
15 20 25 30
Estimate of N
Figure 15. Posterior distributions of abundance for each year (2004-2007) for Southern Brown
Bandicoot at Coopracambra National Park
3.2.1.2.3 Long Nosed Bandicoot
The total number of individuals captured over the period 2004 to 2007 was six. The raw
capture data are shown in Table 8.
Table 8. Raw capture data for Long-nosed Bandicoot at Coopracambra National Park.
n1 = the number of individuals captured in session 1; n2 = the number of individuals
captured in session 2; m2 = the number of previously captured individuals at session 2; u.
= the total number of individuals captured.
Year
n1
n2
m2
u.
2004
2
5
2
5
2005
2
1
1
2
2006
0
0
0
0
2007
0
0
0
0
Estimates of abundance using the modified Lincoln-Peterson method and the Bayesian
method are presented in Table 9. In 2006 and 2007 no actual captures were recorded,
because the Bayesian estimates directly allow for the probability that some individuals could
have been missed the sparseness of the data means that estimates for abundance need to
be viewed with caution.
21
Table 9. Estimates of abundance (SD) for Long-nosed Bandicoot at Coopracambra National Park
Year
LPC
Bayesian
2004
5 (0)
8 (3.5)
2005
2 (0)
4 (2.5)
2006
0 (0)
1 (1.7)
2007
0 (0)
1 (1.7)
3.5.1.2.4 Common Brush-tailed Possum
The total number of individuals captured over the period 2004 to 2007 was 17. The raw
capture data are shown in Table 10.
Table 10. Raw capture data for Common Brush-tailed Possum at Coopracambra National Park.
n1 = the number of individuals captured in session 1; n2 = the number of individuals
captured in session 2; m2 = the number of previously captured individuals at session 2; u.
= the total number of individuals captured.
Year
n1
n2
m2
u.
2004
1
5
1
5
2005
0
0
0
0
2006
0
3
0
3
2007
6
8
2
12
Estimates of abundance using the modified Lincoln-Peterson method and the Bayesian
method are presented in Table 11. Estimates for 2004-2006 are presented for comparative
purposes only, and should not be viewed with any certainty. Estimates for 2007 are
reasonably robust. In general, this result indicates that in 2007 either the actual underlying
abundance increased from some very low but unknown level, or the detection probability for
possums changed, resulting in an increased rate of capture. The inference from this is that
the probability of capturing, rather than the underlying density changed.
Table 11. Estimates of abundance (SD) for Common Brush-tailed Possum at Coopracambra National
Park
Year
LPC
Bayesian
2004
5 (0)
8 (2.7)
2005
0 (0)
1 (1.4)
2006
3 (0)
5 (2.2)
2007
20 (6.5)
18 (4.2)
The posterior densities of abundance for each year derived from the Bayesian approach are
shown in Figure 16. This serves to illustrate the usefulness of this approach. Assuming that
the estimates in years 1 to 3 are reasonable it can clearly be seen that the range of probable
density estimates in year 4 do not greatly overlap the previous years estimates. This would
indicate that there has been an increase in the abundance of possums.
22
2004
0.4
0.15
0.1
0.05
0.3
0.2
0.1
0
0
0
5
10 15 20 25 30
Estimate of N
35
40
0
5
10
2006
0.25
15 20 25
Estimate of N
30
35
40
15 20 25 30
Estimate of N
35
40
2007
0.12
0.1
Probability
0.2
Probability
2005
0.5
Probability
Probability
0.2
0.15
0.1
0.05
0.08
0.06
0.04
0.02
0
0
0
5
10
15 20 25 30
Estimate of N
35
40
0
5
10
Figure 16. Posterior distributions of abundance for each year (2004-2007) for Common Brush-tailed
Possum at Coopracambra National Park.
Estimates for 2004-2006 are not robust and are shown only for comparative purposes.
3.2.2 Pulsed Baiting Program
3.2.2.1 Grampians National Park
Pilot monitoring in 2002-03 detected nine mammal and two reptile species. These included
the four target species Long-nosed Potoroo, Southern Brown Bandicoot, Smoky Mouse and
Heath Mouse, as well as Agile Antechinus (Antechinus agilis), Yellow-footed Antechinus
(Antechinus flavipes), Swamp Rat (Rattus lutreolus), Black Rat (Rattus rattus), Eastern
Pygmy Possum (Cercartetus nanus), Common Brushtail Possum (Trichosurus vulpecular),
Swamp Wallaby (Wallabia bicolor), Stumpy-tailed Lizard (Tiliqua rugosa) and an unidentified
skink. The capture of Southern Brown Bandicoot represents an expansion of the known
range of the species.
3.2.2.1.1 Southern Brown Bandicoot
The total number of individuals captured over the period 2004 to 2007 was 14. The raw
capture data are shown in Table 12. Given the sparseness of the data in 2006 and 2007,
estimates of abundance derived from this data are not reliable and are only shown to
highlight the probable impact of the Mt Lubra fire.
23
Table 12. Raw capture data for Southern Brown Bandicoot at the Grampians National Park.
n1 = the number of individuals captured in session 1; n2 = the number of individuals
captured in session 2; m2 = the number of previously captured individuals at session 2; u.
= the total number of individuals captured.
Year
n1
n2
m2
u.
2004
1
4
0
5
2005
1
8
1
8
2006
0
0
0
0
2007
1
1
1
1
Estimates of abundance using the modified Lincoln-Peterson method and the Bayesian
method are presented in Table 13.
Table 13. Estimates of abundance (SD) for Southern Brown Bandicoot at the Grampians National
Park.
Year
LPC
Bayesian
2004
9 (4.5)
11 (4.7)
2005
8 (0)
17 (6.1)
2006
0 (0)
2 (2.3)
2007
1 (0)
4 (4.2)
The 2006 Mt Lubra fire appears to have affected the capture of Southern Brown Bandicoot
(Figure 17). While the increase from 2004 to 2005 is not significant, the sharp decline in 2006
is notable as is the sustained lower estimate in 2007.
2004
0.12
2005
0.1
0.08
Probability
Probability
0.1
0.08
0.06
0.04
0.04
0.02
0.02
0
0
0
5
10
15 20 25 30
Estimate of N
35
40
0
2006
0.3
5
10
Probability
0.2
0.15
0.1
15 20 25 30
Estimate of N
35
40
35
40
2007
0.2
0.25
Probability
0.06
0.15
0.1
0.05
0.05
0
0
0
5
10
15 20 25 30
Estimate of N
35
0
40
5
10
15 20 25 30
Estimate of N
Figure 17. Posterior distributions of abundance for each year (2004-2007) for Southern Brown
Bandicoot at the Grampians National Park.
24
3.2.2.1.2 Long-nosed Potoroo
During this project, Long-nosed Potoroo was first captured in 2004; the first record in the
Grampians for almost 30 years.The total number of individuals captured over the period 2004
to 2007 was four. The raw capture data are shown in Table 14. Notably, although captures
were sparse prior to the Mt Lubra fire, no long-nosed potoroos were captured in the two
years subsequent to the fire.
Table 14. Raw capture data for Long-nosed Potoroo at the Grampians National Park.
n1 = the number of individuals captured in session 1; n2 = the number of individuals
captured in session 2; m2 = the number of previously captured individuals at session 2; u.
= the total number of individuals captured
Year
n1
n2
m2
u.
2004
1
2
0
3
2005
1
3
1
3
2006
0
0
0
0
2007
0
0
0
0
Although no potoroos where captured in years 3 and 4 the Bayesian process assumes that
the capture probabilities are the same for each year. Therefore, because some individuals
are missed in year 1 and 2 it is therefore likely that some individuals were also missed in
year 3 and 4. These estimates are not robust and are presented to highlight the probable
impact of the Mt Lubra fire (Table 15).
Table 15. Estimates of abundance (SD) for Long-nosed Potoroo at the Grampians National Park.
Year
LPC
Bayesian
2004
5 (2.5)
11 (5.9)
2005
3 (0)
11 (5.9)
2006
0 (0)
3 (3.5)
2007
0 (0)
3 (3.5)
The 2006 Mt Lubra fire has also affected the estimate for N for Long-nosed Potoroo, with a
marked decrease in year 3 (2006) and four (2007; Figure 18).
25
2004
0.1
0.08
Probability
Probability
0.08
0.06
0.04
0.02
0.06
0.04
0.02
0
0
0
5
10
15 20 25 30
Estimate of N
35
40
0
2006
0.2
5
10
0.15
0.1
0.05
15 20 25 30
Estimate of N
35
40
2007
0.2
Probability
Probability
2005
0.1
0.15
0.1
0.05
0
0
0
5
10
15 20 25 30
Estimate of N
35
0
40
5
10
15
20
25
30
35
40
Estimate of N
Figure 18. Posterior distributions of N for each year (2004-2007) for Long-nosed Potoroo at the
Grampians National Park.
3.2.2.1.3 Common Brush-tailed Possum
The total number of individuals captured over the period 2004 to 2007 was 27. The raw
capture data are shown in Table 16.
Table 16. Raw capture data for Common Brush-tailed Possum at the Grampians National Park.
n1 = the number of individuals captured in session 1; n2 = the number of individuals
captured in session 2; m2 = the number of previously captured individuals at session 2; u.
= the total number of individuals captured.
Year
n1
n2
m2
u.
2004
6
7
3
10
2005
6
4
4
6
2006
1
4
1
4
2007
3
5
2
6
Estimates of abundance using the modified Lincoln-Peterson method and the Bayesian
method are presented in Table 17.
Table 17. Estimates of abundance (SD) for Common Brush-tailed Possum at the Grampians National
Park.
Year
LPC
Bayesian
2004
13 (2.9)
13 (3.6)
2005
6 (0)
6 (1.4)
2006
4 (0)
6 (3.8)
2007
7 (1.4)
8 (3.2)
The posterior densities of abundance for each year are shown in Figure 19.
26
Parks Victoria Technical Series No. 59
Final Report 2002-2007
2004
2005
0.15
Probability
Probability
0.2
0.1
0.05
0
0
5
10
15 20 25 30
Estimate of N
35
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
40
5
10
2006
20
25
30
35
40
15 20 25 30
Estimate of N
35
40
2007
0.25
0.25
0.2
0.2
Probability
Probability
15
Estimate of N
0.15
0.1
0.05
0.15
0.1
0.05
0
0
0
5
10
15 20 25 30
Estimate of N
35
40
0
5
10
Figure 19. Posterior distributions for each year (2004-2007) for Common Brush-tailed Possum at the
Grampians National Park.
3.2.2.2 Wilsons Promontory National Park
Prey species monitoring began in 2003-04 and targeted two species identified through pilot
monitoring in 2002-03; Long-nosed Potoroo and Southern Brown Bandicoot. In 2005, two
sites (Roaring Meg and Telegraph Track) were affected by fire in. Data are presented as
non-fire and fire affected areas.
3.2.2.2.1 Long-nosed Potoroo
The total number of individuals captured over the period 2004 to 2007 was 36. The raw
capture data are shown in Table 18.
Table 18. Raw capture data for Long-nosed Potoroo at Wilsons Promontory National Park.
n1 = the number of individuals captured in session 1; n2 = the number of individuals
captured in session 2; m2 = the number of previously captured individuals at session 2; u.
= the total number of individuals captured.
Year
Non Fire Areas
Fire Areas
Total
n1 n2 m 2
u.
n 1 n 2 m2
u.
2004
8, 8, 5
11
6, 5, 3
8
19
2005
8, 10, 7
11
0, 0, 0
0
11
2006
10, 7, 7
10
0, 0, 0
0
10
2007
8, 10, 8
10
2, 1, 1
2
12
Estimates of abundance derived from the modified Lincoln-Peterson method are shown in
Table 19. The impact of the fires on capture and recapture rates is apparent from the
27
Parks Victoria Technical Series No. 59
Final Report 2002-2007
estimates with no long-nosed potoroos captured in 2005 and 2006 and only two individuals
caught in 2007.
Table 19. LPC capture-recapture estimates (SD) of abundance for each year (2004-2007) for Longnosed Potoroos at Wilsons Promontory National Park.
Year
Non Fire Areas
Fire Areas
All Areas
2004
12.5 (1.7)
9.5 (1.8)
22.3 (2.8)
2005
11.4 (0.7)
0 (0)
11.4 (0.7)
2006
10 (0)
0 (0)
10 (0)
2007
10 (0)
2 (0)
12.2 (0.5)
The Bayesian method allows for the probability that some individuals were present but not
detected. Even so, the impact of the fire on the estimate of abundance is apparent (Table
20). As the data in fire-affected areas is sparse, these derived estimates are not robust and
are shown only to highlight the probable impact of the fire.
Table 20. Bayesian capture-recapture estimates (SD) of abundance for each year (2004-2007) for Longnosed Potoroos at Wilsons Promontory National Park.
Year
Non Fire Areas
Fire Areas
All Areas
2004
13 (2.3)
12 (3.8)
22 (2.8)
2005
12 (1.5)
0 (1.1)
12 (1.4)
2006
10 (1.2)
0 (1.1)
10 (1.2)
2007
10 (0.9)
3 (1.9)
12 (1.1)
Figure 20 shows the posterior densities of abundance for non-fire and fire and fire areas
combined for each year from Bayesian model. The probable impact of the fires can be seen
in the decrease in overall abundance in the three years post fire.
28
Parks Victoria Technical Series No. 59
Final Report 2002-2007
2004
2005
0.6
0.5
0.15
Probability
Probability
0.2
0.1
0.05
0.4
0.3
0.2
0.1
0
0
0
5
10
15 20 25 30
Estimate of N
35
40
0
5
10
0
5
10
30
35
40
30
35
40
2007
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Probability
Probability
2006
15 20 25
Estimate of N
15 20 25
Estimate of N
30
35
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
40
5
10
15 20 25
Estimate of N
Figure 20. Posterior distributions of abundance for each year (2004-2007) for all areas combined for
Long-nosed Potoroo at Wilsons Promontory National Park.
3.2.2.2.2 Southern Brown Bandicoot
Southern brown bandicoots were only ever recorded at sites not affected by fire; therefore,
no separate analysis was undertaken. The total number of individuals captured over the
period 2004 to 2007 was six. The raw capture data is shown in Table 21.
Table 21. Raw capture data for Southern Brown Bandicoot at Wilsons Promontory National Park.
n1 = the number of individuals captured in session 1; n2 = the number of individuals
captured in session 2; m2 = the number of previously captured individuals at session 2; u.
= the total number of individuals captured.
Year
n1
n2
m2
u.
2004
3
0
0
3
2005
1
0
0
1
2006
0
2
0
2
2007
2
1
1
2
No further analysis was undertaken as there were too few captures and re-captures in all
years for sensible estimates to be calculated. The LPc approach results in very low
abundance estimates, with no standard deviations able to be calculated. The Bayesian
approach allows for estimates to be calculated, but the estimates of posterior densities are
generally overwhelmed by the prior probabilities due to instances of no captures in session 1
or 2 for some years (i.e. n2 = 0 for 2004 and 2005).
29
Parks Victoria Technical Series No. 59
Final Report 2002-2007
3.2.2.2.3 Common Brush-tailed Possum
This species was only ever recorded at the Sealers Cove site. Two possums were captured
but not tagged in session 1 of 2007. These two records could not be used in the estimates of
abundance. The total number of individuals captured over the period 2004 to 2007 was 13.
The raw capture data are shown in Table 22.
Table 22. Raw capture data for Common Brush-tailed Possum at Wilsons Promontory National Park.
n1 = the number of individuals captured in session 1; n2 = the number of individuals
captured in session 2; m2 = the number of previously captured individuals at session 2; u.
= the total number of individuals captured.
Year
n1
n2
m2
u.
2004
3
4
2
5
2005
1
2
1
2
2006
3
2
1
4
2007
0
5
0
5
Table 23 indicates the estimates of abundance of Common Brush-tailed Possum. As these
were only ever recorded at one monitoring location we did not undertake further analysis.
Table 23. Estimates of abundance (SD) for each year (2004-2007) for Common Brush-Tailed Possum
at Sealers Cove, Wilsons Promontory National Park.
Year
LPC
Bayesian
2004
5.7 (1.1)
8 (3.3)
2005
2 (0)
4 (2.3)
2006
5 (1.4)
7 (3.0)
2007
5 (0)
8 (3.2)
3.2.3 Seasonal Baiting Strategy
3.2.3.1 Little Desert National Park
Pilot monitoring at Little Desert undertaken in 2002 detected six species of mammal, 14
species of reptile and one species of amphibian (Robley & Wright 2003). This included the
first confirmed record of Little Pygmy Possum (Cercartetus lepidus) for that park. Preyspecies monitoring was undertaken from 2003 to 2007. Overall, 28 species were captured
with 515 captures (Appendix 4). In the Eastern Block 17 species from 7 groups were
captured, in the Central Block 14 species from 7 groups were captured, and in the Western
Block 16 species were captured. By far the majority of animals captured were herptofauna.
At all three sites skinks were the most common group captured, with the Obscure Skink
(Morethia obscura) dominating captures. Lizards and amphibians, including the Spade-foot
Toad (Neobatrachus sp.) and the Lined Worm-lizard (Aprasia striolata), were the next most
commonly captured group.
Only 4 species of mammal were captured across all three sites. These were the Western
Pygmy Possum (Cercartetus concinnus), Common Dunnart (Sminthopsis murina; Vulnerable
in Victoria), Silky Mouse (Pseudomys apodemoides) and the introduced House Mouse (Mus
musculus). Of the native mammal species captured, Silky Mouse was the most common,
being captured in all sessions on all sites.
As for Hattah-Kulkyne, we plotted captures per 100 trap nights for each species group for the
two baited sites (Eastern and Central block) and the unbaited site (Western bock). Capture
rates for amphibians and snakes where higher on the Eastern block compared to the
Western block in 2006 and 2007, and capture rates for mammals were higher on the Eastern
30
Parks Victoria Technical Series No. 59
Final Report 2002-2007
block compared to the Western Block in 2007. Capture rates for dragons and skinks
increased on all sites in 2006 and skinks maintained higher capture rates in 2007, suggesting
a response to other environmental factors (Figure 21). Capture rates for all other groups
were highly variable and showed no consistent trend over time.
Am phibians
Captures/100 trap nights
Captures/100 trap nights
6.0
4.0
2.0
0.0
2003
2005
2006
Captures/100 trap nights
3.0
2.0
1.0
0.0
2004
2005
2006
2007
Legless Lizards
5.0
4.0
3.0
2.0
1.0
0.0
2003
2004
2005
2006
2007
2003
2004
2005
2006
2007
Mam mals
3.0
Captures/100 trap nights
Captures/100 trap nights
1.0
2003
0.0
2.0
1.0
0.0
2003
Captures/100 trap nights
2.0
2007
Geckos
4.0
Captures/100 trap nights
2004
Dragons
3.0
2004
2005
2006
2007
2006
2007
Skinks
18.0
16.0
14.0
12.0
10.0
8.0
6.0
4.0
2.0
0.0
2003
2004
2005
2006
2007
Snakes
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
2003
2004
2005
Figure 21. Native species response on the Eastern, Central and Western blocks, Little Desert National
Park.
Dashed lines = Eastern block, high intensity baiting, dotted lines = Central block, medium
intensity baiting, and solid lines = Western block, nil-treatment block.
31
Parks Victoria Technical Series No. 59
Final Report 2002-2007
4 DISCUSSION
Parks Victoria established the Fox AEM project to examine the effectiveness of different
spatial and temporal intensities of baiting on foxes; changes in native species associated
with fox control; the costs and benefits of each strategy, and the applicability of AEM to
broad-scale pest management.
4.1 Effective Baiting Strategies
All programs using continuous-annual or pulsed baiting resulted in reduced levels of bait take
by foxes regardless of the spatial intensity of baiting. While a decrease in bait take is
assumed to represent a decrease in fox density, the relationship between bait take and fox
density remains unknown, although this relationship is presumably not linear.
Results from the sand plot monitoring at Hattah-Kulkyne and the Grampians further support
the conclusion that continuous-annual or pulsed baiting resulted in reduced fox abundance.
Fox activity (as assessed by sand plot monitoring), is also thought to be related to fox
abundance. At both of these sites, fox activity decreased after initial poison baiting and in the
case of Hattah-Kulkyne, generally remained lower than during the free feed period. At
Coopracambra no change in the sand plot index was detected, however a change was
observed for bait take. This may be partially due to the spread of sand plots for activity
monitoring being restricted at Coopracambra because of the limited number of access tracks.
While continuous annual and pulsed programs did seem to reduce fox abundance
(expressed as bait take and sand plot activity monitoring), this was not observed for seasonal
baiting. At Little Desert there was no short-term reduction in bait take within a baiting
season. Furthermore, bait take levels and sand pad activity showed no consistent decline
across years. Similarly, no reduction in bait take across time was observed over the six years
for which the Grampians seasonal perimeter baiting program operated.
The availability of staff resources, budgets and the values being protected (e.g. native fauna)
need to be considered when selecting a baiting strategy. The pulsed baiting strategies used
in the fox AEM project were comparable in cost to the continuous-annual strategies. The two
seasonal baiting strategies used at Little Desert were cost almost 70% cheaper to deliver on
average, did not lead to sustained reduction in fox abundance (assessed by bait take and
sand pad monitoring). However, if protection of a seasonal resource (e.g. nesting birds)
required only a short period of reduction or temporary removal of predation pressure, short
term or seasonal programs may be appropriate.
At all sites, including those with a demonstrable reduction in bait-take, foxes persisted in the
landscape, evidenced by a residual level of bait-take. It is not known if this is due to a subset
of the population that are bait adverse, dispersing or immigrating foxes or a combination of
these factors. What is clear is that even high intensity continuous-annual programs are
unable to remove all foxes for even a short period. Knowledge of the source, timing, age, and
sex of these animals may assist managers to better-design fox control programs in future.
Analysis of the temporal patterns of movement on fox activity in response to control actions
may reveal patterns that could be used to target specific areas with supplementary control
actions or better focus limited resources. Parks Victoria could potentially provide logistic and
infrastructure support to facilitate research in this area.
The fox control strategies used in the AEM project involve the use of a single tactic, poison
baiting with 1080. This is also the most widely-used tactic across all of Parks Victoria’s fox
control programs. There are two important points that need to be considered in relation to the
continued use of 1080. First, the consumption of sub-lethal doses of 1080 as a result of bait
caching and breakdown of 1080 over time may contribute to the development of bait
aversion in foxes. Research is needed to determine the nature and extent of sub-lethal doses
and the implications this has for the effectiveness of baiting programs. Second, it is now
32
Parks Victoria Technical Series No. 59
Final Report 2002-2007
accepted that some animals can develop a tolerance to 1080, irrespective of any natural
exposure to fluoroacetate-bearing plants. For example, some free-ranging rabbit populations
are becoming more tolerant to 1080 (Twigg et al. 2002). The increased tolerance in these
rabbits was directly related to the length and intensity of past exposure to 1080 baiting
campaigns. Research into alternative toxins may help in overcoming the potential
implications that bait tolerance may have for the effectiveness of baiting in managing fox
predation. Para-aminopropiophenone (PAPP), which is currently being researched, appears
to hold some promise as an alternative toxin to 1080. Alternative toxins to control foxes in
rabies outbreaks are being investigated in the UK and may also have some useful
implications for fox management in Australia.
A significant component of the cost of implementing the Fox AEM program was sand plot
activity monitoring. This was instigated to provide a measure of the fox population
independent of bait take, which has some shortcomings due to issues such as caching and
bait avoidance. Sand plot monitoring is time consuming, affected by weather and requires
and high level of skill to identify correctly the spoor of foxes and other species such as feral
cats or wild dogs on a variety of different substrata under changing conditions. Data collected
through the Fox AEM project on the time and costs to implement sand pad monitoring and
the level of variation in the data collected, suggest substantially more resources would need
to be invested in implementing this form of monitoring to enable detection of change in fox
activity. As such, we feel Parks Victoria should consider the appropriateness of this
monitoring approach for foxes on a case by case basis. Remote cameras may be one viable
option for monitoring foxes. Recent investigations by ARIER using heat-in-motion activated
cameras to investigate activity and site occupancy rates of foxes, feral cats, spot-tailed quolls
and other native mammals indicate this approach is effective at detecting these species. For
example, a study in the Great Otway National Park found differences in detection rates for
foxes and feral cats between baited and unbaited areas (J. Nelson unpublished data). While
there may be some reluctance to using this approach due to initial set up costs (approx.
$1000/ camera unit), it should be realised that this approach can have multiple applications,
e.g. native species monitoring, enforcement monitoring, and units can be shared between
parks. Current work is looking at the relative cost-effectiveness of motion-activated cameras.
4.2 Changes in Native Species
The native fauna monitoring programs established at each of the Fox AEM sites identified
the presence and persistence of a range of native species likely to be under threat from fox
predation. While the monitoring program did not detect a significant change in abundance of
any species, it is assumed that the reduction in foxes, as measured through decline in bait
take and in some parks sand plot activity, will benefit those species. Across time, if such
reductions in fox activity can be maintained, it is hoped that a positive response will be
observed. Further monitoring is required to see if this is the case.
Although not the aim of native species monitoring implemented as part of the Fox AEM
project, we have also been able to identify the short-term impact on abundance of some
native fauna species resulting from wild fires at two of the parks involved; Grampians and
Wilsons Promontory. Continuing these monitoring programs may be useful in tracking the
response of native fauna at these sites across time.
The lack of a consistent response in native fauna at Little Desert is not surprising given that
we did not detect any long-term reduction in fox bait take or sand plot activity. Continuation of
the native species monitoring programs at Coopracambra and Little Desert is unlikely to
detect anything but very large changes in abundance. Monitoring at Hattah-Kulkyne ceased
in 2005.
At the outset of the program it was anticipated that coherent and reliable native species
responses would not be measurable for several years (Robley & Choquenot 2002). For sites
where mammals were the monitoring target, there are no consistent trends in capture data
33
Parks Victoria Technical Series No. 59
Final Report 2002-2007
for any species. In a number of cases, estimates of abundance using either the modified
Lincoln-Petersen or Bayesian methods were not possible as the data are too sparse to
provide robust estimates. Similarly, given the low capture rates, the CPUE indices would be
comparable to the raw capture numbers.
Low capture rates can arise from two sources, a) low capture probability, i.e., the chance of
catching an individual of a species if it occurs at the site is small, and b) sampling effort is too
low, i.e. the number of trap nights, the number of trapping locations or a combination of these
is insufficient.
We investigated the population growth needed to detect a significant difference at least 80%
of the time using capture rates that encompass the range found from the trapping data
across all sites over the past 4 years. For example, a population that started with 10
individuals with a capture probability of 0.5 would need 6 years of sampling to detect an
annual increase of 20%. Four years of sampling would be needed to detect an annual
increase of 40% (Figure 22).
While for some populations the capture probabilities are reasonable (e.g. 0.74 for Longnosed Potoroos at Wilsons Promontory) there is no detectable change in the population. This
suggests that the population levels across all parks are low and as a result, the trapping
effort has been unable to detect any changes if they have occurred.
An additional factor may be that the size of the sampling area (2.5 ha) was insufficient to
precisely measure changes in population abundance within a site. Often the same individuals
were captured within a session, between sessions and between years.
2.00
p = 0.3
p = 0.5
p = 0.7
Annual Population Growth
1.80
1.60
1.40
1.20
1.00
3yrs
4yrs
5yrs
6yrs
7yrs
Years of Sampling
Figure 22. Number of years sampling needed to detect changes in population growth.
A central tenet of adaptive management is to establish a continuous learning process that is
attuned to new information by reformulating hypotheses and models, and understanding
policy implementation as experiments. An unintended but significant outcome of the AEM
project has been to inform us of the ability of the native species response monitoring
program to detect changes in abundance.
The native species monitoring program was designed to enable a high likelihood of detecting
a doubling of specific species abundance as estimated using either mark-recapture
techniques or an index of abundance such as trap success. Since the inception of the fox
AEM project, new methods and approaches have been developed for monitoring and
evaluating responses of native species to large-scale management actions that are aimed at
conserving biodiversity.
34
Parks Victoria Technical Series No. 59
Final Report 2002-2007
In Victoria, two fox control projects (Southern Ark in East Gippsland and Glenelg Ark in the
far south-west of the state) have been established to operate across large areas and span a
range of land tenure categories. These projects are approaching the issue of native fauna
response by looking at changes in site occupancy of a range of species. The basic premise
is that as predation pressure is eased by the reduction in fox numbers, species that are
regulated by predation will increase in number and sites that were not occupied will become
occupied. While not always directly related to abundance, changes in occupancy by rare
species can be related directly to changes in abundance (Mackenzie 2005). This approach
may have utility for any future assessment for changes in native fauna resulting from largescale management action.
4.3 AEM and Parks Victoria
In Australia, adaptive management has been incorporated into the management of aquatic
resources to various degrees, including some of the most comprehensive and successful
applications of adaptive management in general (Hughes et al. 2007). Most commonly
however, only some of the initial steps of AEM are attempted (Grayson & Doolan 1995). To
our knowledge, this is the first time AEM has been applied to terrestrial ecosystems in
Australia.
Parkes et al. (2006) list Institutional aspects of adaptive management that are often seen as
an obstacle for this management approach. These include:
• Risk aversion of some managers
• Inadequate institutional structures and stakeholders participation
•
•
Incomplete or ineffectual implementation of a study plan
Lack of commitment to monitoring, evaluating and reporting
•
Uncertain or inadequate funding for monitoring and analyses
•
Institutional ‘memory loss’ regarding what has been learnt
In addition, the temporal and spatial scales that are relevant to many management problems
make it difficult to identify clearly at which stage adaptive management has failed or
succeeded. The types of situations where adaptive management has been attempted include
the management of long-lived organisms (such as trees) and ecosystems in which the
responses to management can occur at many levels and can be perpetuated through the
system across time. Thus, monitoring on a temporal scale that is too short may result in
information about short-term and transient responses, but provide little information on longerterm, threshold responses. In addition, short time scales are generally inadequate to
evaluate the effects of relatively rare environmental events such as large disturbances and
catastrophes, e.g. large fires.
Current management structures in many conservation agencies present managers with a
dilemma by devolving decision-making to operational levels, but imposing ‘standard
operating procedures’ and ‘business planning’ processes from above (Parkes et. al 2006).
Devolution encourages innovation and leads to different management approaches being
applied to apparently similar problems, despite standard operating manuals. Business
planning and funding constraints lead to contestability and arguments over whose
innovations are best. In addition, business operating procedures and flat management
structures where operational management is responsible for delivery of outcomes allows
operational managers the freedom to alter programs. These managers are usually operating
with limited budgets and resources and are responding to local changes in management
priorities that are seen to outweigh the need to maintain a program that has been operating
for sometime with no obvious operational outcome. In addition, AEM projects often run over
many years, as temporal changes resulting from management intervention require long
periods to permeate through the system. This can be problematic as funding and
35
Parks Victoria Technical Series No. 59
Final Report 2002-2007
government cycles are often shorter than the time required for a complete cycle of an AEM
project. Hence, management can be put under significant pressure to show results, failure to
do so can lead to pressure to “adapt” the project to meet new policy or funding positions.
One consequence of the AEM approach is that some management strategies may be found
to be more effective than others are. As managers become more aware that they are
managing in an apparent sub-optimal manner they will naturally wish to alter their approach.
However, changing the management strategy at sites too early will affect the capacity of this
project to provide a solid understanding of the differences in the effectiveness of different
management strategies.
There have been several changes and operational challenges to the Fox AEM program since
its inception in 2001. Discovery Bay Coastal Park was included in the initial design and was
discontinued in 2003 due to logistical problems associated with extreme energy tidal
movements destroying bait stations and sand plots. Monitoring of the target species, Hooded
Plover (Thinornis rubricollis) was also complex (multiple predators) and problematic (access
was limited due to tidal movement). Eumeralla Coastal Park was included as a replacement
for the Discovery Bay site in 2004, but work here was discontinued as it suffered from many
of the same problems as Discovery Bay.
The baiting program at the Grampians National Park was altered from a perimeter and
seasonal program in 2003 (two years after the commencement of the project) to a pulsed
program. Associated with this was an increase in the number (sampling effort) of sand plots.
A major fire also affected a significant proportion of the Park in 2005/06 including the majority
of the baited area. The baiting program was adjusted following this fire, combining two of the
four pulses into one Spring/Summer pulse.
The baiting and sand plot monitoring at Coopracambra was affected by external contractors
not fulfilling their contract requirements and by inconsistencies in data recording. Prey
species monitoring at Coopracambra was affected by a change in protocols and a loss of
data when operational aspects of the program were included in Southern Ark and there was
a change in personnel delivering the program.
Native species monitoring at Wilsons Promontory did not begin at all sites in the first year of
the project, sand plot monitoring was not fully operational until the fourth baiting pulse began
and wild fire burnt a significant area of the park in 2005, including several Fox AEM native
species monitoring sites.
At Hattah-Kulkyne, discontinuity in the availability of staff to deliver the program interrupted
the baiting program across time. In 2006, it was not possible to implement any prey species
monitoring or bating programs.
A significant weakness in the design of this project was the inability to assign treatment and
non-treatment areas in some sites and monitoring of nil-treatment sites was only possible at
two sites. The project would also have benefited through incorporation of modelling used in
more formal adaptive management programs. For example, a spatially-explicit predator-prey
population model, which included the response of selected prey species to various control
strategies, would have enabled expected changes to be predicted and compared with the
measured responses. This was beyond the resources of the project.
Large-scale sustained predator control programs undertaken by government agencies are
common in Australia. However, a common problem is that it is difficult to sustain national,
State or individual operations over long periods of time (Reddiex et. al 2004). We suggest
adaptive management is a useful tool to assist maintaining pest control operations over a
long time frame. Adaptive management places the routine monitoring done by managers in a
wider context. It allows managers to coordinate data collection across different operations to
improve the quality of routine procedures and analyses. By using data to predict
consequences of management actions and evaluating whether those predictions are
realised, adaptive management can help ensure business planning considers the ecology of
36
Parks Victoria Technical Series No. 59
Final Report 2002-2007
the systems being managed, rather than being driven by budget constraints. Explicit
bioeconomic modelling can be incorporated to provide predictions about costs and benefits
in terms that managers at all scales can relate to. Adaptive management also decreases
uncertainty in complex management systems or decreases the risk of failure (or
unsustainability) by making the uncertainty more explicit.
This project aimed to test the application of an adaptive experimental management approach
to improve understanding about the management of foxes in parks and reserves across
Victoria. Across the duration of the project, a number of shortcomings not foreseen at the
commencement of the project were identified. This is not surprising given that it is, as far as
we are aware, the first attempt to implement an AEM approach for large-scale pest
management in Australia and certainly Parks Victoria’s first attempt at implementing such an
approach. Despite these shortcomings, we believe the project has yielded a great deal of
information that will assist in improving Parks Victoria’s fox management programs, as well
as giving a better understanding of how an adaptive management approach may be better
implemented in future.
37
Parks Victoria Technical Series No. 59
Final Report 2002-2007
5 ACKNOWLEDGMENTS
Many people have contributed to the design and implementation of the AEM project since it
began, including:
Alan Braithwaite, David Choquenot, Nick Clemann, Andrew Dennis, Susan Hansen, Marcel
Hoog Antink, Matt Hoskins, Mick Keenan, Robyn Korn, Alison Marion, Don McCarthy, Kate
Millar, Phil Murdoch, John Parkes, Graham Parkes, Phil Pegler, Mal Pye, Rick Ressom,
Dave Ryan, Peter Sandell, Damien Skurrie, Anthony Stasiak, Mike Stevens, Jonathon
Stevenson, Bruce Taylor, Elaine Thomas, Jeremy Tscharke, Sally Troy, Tony Varcoe, Ian
Walker, Andrew Wise and a small army of volunteers.
38
Parks Victoria Technical Series No. 59
Final Report 2002-2007
6 REFERENCES
Allen L., Engeman R. & Krupa H. (1996). Evaluation of three relative abundance indices for
assessing dingo populations. Wildlife Research 23,197-206.
Caughley G. (1977). Analysis of Vertebrate Populations. New York, John Wiley.
Choquneot D. & Robley A. (2001a). Proceeding of a workshop on Adaptive Experimental
Management of Fox Control for Parks Victoria 1. Optimising fox control through adaptive
experimental management. Held on 13 July 2001 Brimbank Park, Melbourne. Department of
Natural Resources and Environment.
Choquneot D. & Robley A. (2001b). Proceeding of a workshop on Adaptive Experimental
Management of Fox Control for Parks Victoria 2. Study sites and design of the Adaptive
Experimental Management project. Held on 13th August at Bairnsadale and 15th August at
Horsham 2001. Department of Natural Resources and Environment.
Ellison A. M. (2004). Bayesian inference in ecology. Ecology Letters 7, 509-520.
Engeman R. M., Pipas M. J., Gruver K. S. & Allen L. (2000). Monitoring coyote population
changes with a passive activity index. Wildlife Research 27, 553 - 557.
Grayson R. B. & Doolan J. M. (1995). Adaptive environmental assessment and management
(AEAM) and integrated catchment management. Land and Water Resources Research and
Development Corporation, Canberra.
Hone J. (1994). Analysis of vertebrate pest control. Cambridge University Press, Melbourne.
Hughes T. P., Gunderson L.H., et al. (2007). Adaptive Mangement of the Great Barrier Reef
and the Grand Canyon World Heritage Areas. Ambio 36(7), 586-592.
MacKenzie D.I. (2005). What are the issues with ‘presence/absence’ data for wildlife
managers? Journal of Wildlife Management 69, 849-860.
Mahon P. S., Banks P. B. & Dickman C. R. (1998). Population indices for wild carnivores: a
critical study in sand-dune habitat, south-western Queensland. Wildlife Research 25, 11-22.
Manning T., Daniel Edge W. & Wolff J.O. (1995). Evaluating Population-Size Estimators: An
Empirical Approach Journal of Mammalogy, 76, 149-1158.
McLeod R. (2004). Counting the cost: Impact of invasive animals in Australia. Cooperative
Research centre for Pest Animal Control, Canberra.
Marcott B. G. (1998). Selecting appropriate statistical procedures and asking the right
questions: a synthesis. In: Statistical Methods for Adaptive Management Studies (eds Sit V.
and Taylor B.), pp. 129–143. B.C. Ministry of Forests, Forestry Division Services Branch
Victoria, B.C.
Orell P. (2004). Fauna monitoring and staff training: Western Shield Review—February 2003.
Conservation Science Western Australia 5, 51–95.
Parkes J., Robley A. & Choquenot D. (2006). Adaptive management experiments in
vertebrate pest control in New Zealand and Australia. Wildlife Society Bulletin 34, 229-236
Reddiex B., Forsyth D. M. et al. (2004). Review of existing red fox, wild dog, feral cat, feral
rabbit, feral pig, and feral goat control in Australia. I. Audit. Unpublished report for the
Department for the Environment and Heritage, Canberra. Heidelberg, Vic., Arthur Rylah
Institute for Environmental Research, Department of Sustainability and Environment.
39
Parks Victoria Technical Series No. 59
Final Report 2002-2007
Robley A. & Wright J. (2003). Adaptive Experimental Management of Foxes. Annual Report
for Year 2: July 2002 –2003. Parks Victoria Technical Series No. 2. Parks Victoria,
Melbourne.
Robley A. & Wright J. (2004). Adaptive Experimental Management of Foxes. Annual Report:
July 2003 –2004. Parks Victoria Technical Series No. 20. Parks Victoria, Melbourne.
Robley A. & Choquenot D. (2002). Native species response monitoring program for the
adaptive experimental management fox control project. Arthur Rylah Research Institute.
Report to Parks Victoria.
Saunders G., Coman B., Kinnear J. & Braysher M. (1995). Managing Vertebrate Pests:
Foxes. Australian Government Publishing Services, Canberra.
Twigg L. E., Lowe T. J. & Martin G. R. (2002). Evidence of pesticide resistance in medium
sized mammalian pests: a case study with 1080 poison in Australian rabbits. Journal of
Applied Ecology 39, 549-560.
Wade P. R. (2000). Bayesian methods in conservation biology. Conservation Biology
14:1308-1316.
Walters C. J. (1986). Adaptive Management of Renewable Resources. Macmillan, New York.
Walters C. (1997). Challenges in adaptive management of riparian and coastal ecosystems.
Available from URL: http://www.bdt.fat.org.br/ cons_ecol/toc.html Conservation Ecology
online 1, 21.
Walters C. & Holling C. S. (1990). Large-scale management experiments and learning by
doing. Ecology 71, 2060–2068.
Walters C., Korman J., Stevens L. E. & Gold B. (2000). Ecosystem modelling for evaluation
of adaptive management policies in the Grand Canyon. Conservation Ecology 4, 9–13.
Zar J. H. (1999). Biostatistical Analysis. (Prentice Hall: New Jersey).
40
Parks Victoria Technical Series No. 59
Final Report 2002-2007
APPENDIX 1
A1. Summaries of fox control strategies in each part in the
fox AEM project.
A1.1 Coopracambra National Park
The focus of this program is the broad scale suppression of foxes for the protection of a wide
range of potential prey species. Prior to the establishment of the Fox AEM project, there was
no fox control undertaken in the park. The program covers 118 km of track with 74 bait
stations spaced at 1.2 – 1.5 km intervals. Foxoff baits are being utilised and the program
runs on a continuous annual basis. Establishment of the baiting program was facilitated via
an external contractor. The seventy-four bait stations were established in December 2001.
Poison Foxoff baits were first buried in the bait stations on the 21st January 2002 after a six
to eight week free feed program. Bait stations were checked every two weeks during the free
feed period then every two days for the first two weeks of poisoning. Following this checking
has occurred every 3 – 4 weeks.
A1.2 Discovery Bay Coastal Park (Discontinued in 2002)
The baiting program at Discovery Bay was in operation prior to the AEM project but was
redesigned to gain more intense coverage. The focus of the baiting program at Discovery
Bay has been the protection of nesting shorebirds (Hooded Plover and Little Tern). A
seasonal baiting program using Foxoff baits runs between August / September and
November / December each year. In year one bait stations were located along the northern
(inland) boundary and at an internal site named Swan Lake. Bait stations are spaced at 1-km
intervals covering approximately 44 kilometres and these were checked every two weeks
with all baits being replaced at the time of checking. New bait stations were established
progressively from early August 2001, with up to 44 bait stations being progressively used
throughout the baiting program. The operation of each bait station varied as the resources
required to complete the task were underestimated. In 2002 the program was adjusted, with
an additional 40 bait stations included along the beach. Sand pads are checked before,
during and after the seasonal baiting program. The program was discontinued late in 2002.
A1.3 Grampians National Park
Prior to the commencement of the AEM project, the focus of the Grampians baiting program
had been the protection of the previous Brush-tailed Rock-wallaby colony, Heath and Smoky
Mouse populations and involvement with good neighbour programs on the boundary of the
Park. These programs were incorporated into the AEM project when it began. The program
at Red Rock covered 58 km of track with bait stations every 200 metres. This program was
annual, with baits checked every two to three weeks throughout the year, at which time all
baits are replaced. This program also covers areas of heath where the Heath Mouse is
known to occur. The perimeter-baiting program surrounds the Grampians National Park, with
bait stations spaced every 200m. Baiting of 1466 bait stations occurs between February and
June, with bait stations checked approximately every two weeks. Poisoned 1080 Foxoff baits
are used in all bait stations. Both the Red Rock and the perimeter baiting programs were
existing control operations prior to the commencement of the AEM project.
The baiting program at the Grampians National Park was modified in 2003, when the existing
perimeter program was found to be ineffective in reducing fox activity. The modified program
A1.1
Parks Victoria Technical Series No. 59
Final Report 2002-2007
encompassed 407 bait stations spaced at 1 km intervals throughout the central section of the
park (rather than just around the perimeter). The baited area was expanded in 2006
(following the Mt Lubra fire) to encompass 710 bait stations.
A1.4 Hattah-Kulkyne National Park
There was no fox control in this park prior to the establishment of the Fox AEM project. The
AEM program covers approximately 60% of the park, with the remaining 40% acting as the
experimental control, or non-treatment site. Baiting, using free feeds and 1080 poisoned
liver, is carried out on a continuous, annual basis with bait stations spaced at 1 km intervals
and stations checked every two to three weeks. Baits are changed over at the time of
inspection. Bait stations were established at Hattah-Kulkyne between October 2001 and
February 2002. A five-week free feeding period then commenced. A total of 137 bait stations
are in place.
A1.5 Little Desert National Park
The general aim of the fox control program in the Little Desert has been for the protection of
Mallee Fowl and other fauna. The Little Desert National Park’s baiting program was
established prior to the AEM project. The AEM design altered the program in a minor way by
increasing the distances between bait stations. The Little Desert has been divided into three
discrete sites;
•
•
•
The East Block is 477.8 km2 containing 220 km of internal and perimeter tracks. Bait
stations are spaced at approximately 1.5-km intervals resulting in 137 bait stations.
The Central Block is 451.2 km2 with 132 km of track. Bait stations are 1.5 km apart
resulting in 88 bait stations.
The West Block is 374.1 km2 and acts as a non-treatment site.
The new program commenced in November 2001. The baiting program runs from
approximately October/November to March/April with bait stations checked and baits
replaced every three to four weeks.
A1.6 Wilsons Promontory National Park
The baiting program for the AEM project at Wilsons Promontory is a continuation of an
existing program. The focus of the fox control program has been on the broad scale
suppression of foxes to protect a wide range of potential prey species. At the
commencement of the AEM project, Wilsons Promontory was been divided into four
management areas. The Isthmus forms area 1 and is a high intensity baiting area, the
Central section forms area 2 and is a low intensity baiting area, the Southern section forms
area 3 and is a low intensity baiting area. The North-east section of the park forms area 4.
Fox control is not currently done in Area 4. The intention of dividing the park into different
areas was to compare different baiting intensities. However, analysis indicated that these
sites were not spatially independent and no difference was detectable between treatments.
The baiting program consists of pulsed baiting using poisoned 1080 Foxoff baits, with bait
stations at 1-km intervals. A pulse of baiting lasts for 6 – 8 weeks. At the end all untaken
baits are retrieved and replaced at the beginning of the next pulse several weeks later. A
total of 164 bait stations are operated within the park. There is no free feeding, and liver bait
are used on beaches when increased amounts of beach-wash are available. Baits are
checked every week with taken baits replaced.
A1.2
Parks Victoria Technical Series No. 59
Final Report 2002-2007
APPENDIX 2
A2. Passive Activity Index Procedure (Sand Plot
Monitoring)
This procedure describes the method for establishing sand plots as used in the Glenelg Ark
Monitoring and Evaluation Plan. It serves as a general overview for the implementation of
sand plot monitoring.
A2.1 Background
The Passive Activity Index, or Allen Index, is a way of using animal tracks to estimate
changes in the relative activity of animals in an area. The tracks of animal species on
constructed sand plots placed at intervals in a landscape are counted over a short period.
The number of tracks counted is thought to be closely related to their abundance. Counts of
tracks are therefore an indirect method of monitoring animal populations.
The Allen Index should not be used to estimate numbers or absolute densities of animals in
an area.
Sand plots are raked patches of sand or other fine soil material used to register the tracks of
passing animals.
A2.2 Method
TRACK
1 km
Step One: Pre-trip—map transect localities
The number and location of sand plots will have been
determined prior to establishing field sites.
Sand plot
Sand plots should be in areas where surveys can be
repeated over time. There should be a minimum of
vehicular and foot traffic. Sand plots will be given a
name/unique number and their location recorded using a
GPS, the data down loaded and mapped.
1
m
1 km
1m wide x Spans road
Step Two: Equipment Needed
Sand plot
1
m
1 km
1m wide x Spans road
1m wide x Spans road
1m
Sand plot
You will need the following tools and equipment:
•
•
Metal rake with a heavy spine
Shovel
•
•
Medium and fine garden sieves
Surveyor’s tape
•
•
Field Guide to Tracks and Traces
Sketchpad and pencils
•
Map showing location of transects
•
Digital camera
Sand plots will be placed at 1 km spacings along the
track, as shown in the diagram to the left.
A2.1
Span of Track
Parks Victoria Technical Series No. 59
Final Report 2002-2007
Step Three: Establish Field Sites & Sand Plots
Start early in the morning.
At the beginning of each run, set your vehicle odometer to zero. Use the odometer to
measure 1km to each successive plot. Record the odometer reading at each plot and take a
GPS position.
Sand plots should be a minimum of 1m wide (approx. 3 rake hoe widths). If you are using a
road or track, make the plot 1m wide, and stretch it from one road shoulder to the other.
Prepare each surface by raking flat. Remove sticks, rocks, large pebbles and other debris.
Use the back of the rake to level the surface.
For best results, fill sieves with local soil and sieve over the surface until there is a coating of
relatively fine material.
Place a standard mark (cross) in one corner of the sand plot (e.g. south-west). This is used
to ensure weather conditions have not obscured marks.
Mark the on-ground location of each sand plot with brightly coloured surveyors’ tape a few
metres before the plot and at eye level. First and last plots can be marked with two strands of
tape. Mark the exact position of the sand plots on an accurate map.
When you have made the last sand plot, if possible, exit the area by another route to avoid
driving over the plots.
Step four: Count Tracks on Sand Plots
Check sand plots early on the morning after you constructed them. Count for three
consecutive mornings. If a day(s) is lost (i.e. rained out) that day must be repeated within 5
days, otherwise the whole three days must be repeated.
Count the number of individual animals that cross the sand plot. Examine the plot carefully.
Has an animal crossed the plot, turned, and crossed again? If this happens, the animal
should only be recorded once. Above all, be consistent on how you record such intrusions.
Count tracks for all species. If you do not know the species, but know the type of animal,
record this. For example, if you see a small macropod track, and you don't know which
species it is, record it as ‘macropod’. You will often encounter bird tracks. Some tracks, such
as Ibis, will be easy to recognise, while others will not. If there is any doubt as to which
species, record as ‘bird’, and indicate size.
You can take photographic images of tracks for later identification. However, it is difficult to
take good photos of tracks, and it may be better to make sketches.
Make absolutely certain that you record the name and location of the sand plots that you are
working on. Note any conditions that may be important, for example overnight and current
weather that may affect track visibility.
When you have no tracks on a plot, indicate this with a zero. However, if a plot is
washed out, damaged by wind or unreadable, indicate this with a symbol, not a zero (e.g. φ
or / ). This can be important for calculating the index and variance estimates.
If you are counting tracks again the following morning, resurface each sand plot as you
finish.
A2.2
Parks Victoria Technical Series No. 59
Final Report 2002-2007
APPENDIX 3
A3. Costs of Implementing Fox AEM
Table A3.1. Hattah-Kulkyne: Annual / Intensive Program
Control Program
Unit
Unit Cost
($)
Total Cost
($)
*Area
treated
(ha)
Cost($) / Ha
Fox Monitoring Program
Staff (hrs)
Vehicle (km)
648
36.15
23,786.00
1,800
1.24
2,232.00
405
36.15
14,633.00
1,800
1.24
2,232.00
28,800
0.89
28,800
0.59
Sand Plot Monitoring
Staff (hrs)
Vehicle (km)
Total Cost ($)
1.48
* Whole park is 48 800 ha
Table A3.2. Coopracambra: Annual / Intensive Program
Control Program
Unit
Unit Cost
($)
Total Cost
($)
Area
treated
(ha)
Cost($) / Ha
Fox Monitoring Program
Staff (hrs)
Vehicle (km)
576
36.15
20,822
2,124
1.24
2,634
352
36.15
12,725
2,832
1.24
3,512
38,800
0.60
38,800
0.42
Sand Plot Monitoring
Staff (hrs)
Vehicle (km)
Total Cost ($)
1.02
Table A3.3. Grampians National Park: Pulsed / Moderate Intensity Program
Control Program
Unit
Unit Cost
($)
Total Cost
($)
Area
treated
(ha)
Cost($) / Ha
Fox Monitoring Program
Staff (hrs)
Vehicle (km)
1,160
36.15
41,934.00
30,600
1.24
37,944.00
669
36.15
24,184.00
10,460
1.24
12,970.00
72,520
1.10
72,520
0.51
Sand Plot Monitoring
Staff (hrs)
Vehicle (km)
Total Cost ($)
1.61
A3.1
Parks Victoria Technical Series No. 59
Final Report 2002-2007
Table A3.4. Wilsons Promontory National Park: Pulsed / Moderate Intensity Program
Control Program
Unit
Unit Cost
($)
Total Cost
($)
*Area
treated
(ha)
Cost($) / Ha
Fox Monitoring Program
Staff (hrs)
708
36.15
25,594.00
1,132
1.24
1,404.00
Staff (hrs)
351
36.15
12,688.00
Vehicle (km)
688
1.24
853.00
Vehicle (km)
36,000
0.75
36,000
0.38
Sand Plot Monitoring
Total Cost ($)
1.13
* Whole park is 50,000 ha
Table A3.5. Little Desert National Park Eastern Block: Seasonal / Medium Intensity
Control Program
Unit
Unit Cost
($)
Total Cost
($)
Area
treated
(ha)
Cost($ / ha)
Fox Monitoring Program
Staff (hrs)
Vehicle (km)
221
36.15
7,982.00
4,835
1.24
5,995.00
265
36.15
9,578.00
1,558
1.24
1,932.00
47,600
0.22
47,600
0.29
Sand Plot Monitoring
Staff (hrs)
Vehicle (km)
Total Cost ($)
0.51
Table A3.6. Little Desert National Park Central Block: Seasonal / Low Intensity Program
Control Program
Unit
Unit Cost
($)
Total Cost
($)
Area
treated
(ha)
Cost($ / ha)
Fox Monitoring Program
Staff (hrs)
Vehicle (km)
147
36.15
5,321.00
3,793
1.24
4,703.00
265
36.15
9,578.00
2,798
1.24
3,470.00
45,500
0.29
45,500
0.24
Sand Plot Monitoring
Staff (hrs)
Vehicle (km)
Total Cost ($)
0.53
A3.2
Parks Victoria Technical Series No. 59
Final Report 2002-2007
APPENDIX 4
A4. Species Captured in Native Species Monitoring (Hattah-Kulkyne
and Little Desert national parks).
A4.1. Species within groups captured at Hattah-Kulkyne National
Park, 2004-2007
The herptofauna groups are based on: Agamids (dragon), Gekkonids (geckos),
Pygopodids (legless lizards), Scincids (skinks) and snakes (families have been grouped
into one class).
Group
Aves
Snake
Snake
Dragon
Dragon
Dragon
Snake
Snake
Snake
Amphibians
Amphibians
Geckos
Geckos
Geckos
Geckos
Geckos
Mammals
Mammals
Mammals
Mammals
Legless lizards
Legless lizards
Legless lizards
Legless lizards
Skink
Skink
Skink
Skink
Skink
Skink
Skink
Skink
Skink
Skink
Skink
Skink
Varanids
Scientific Name
Common Name
Ramphotyphlops bicolor
Ramphotyphlops bituberculatus
Amphibolurus nobbi
Ctenophorus fordi
Pogona vitticeps
Pseudonaja textilis
Brachyurophis australis
Suta nigriceps
Limnodynastes dumerillii
Limnodynastes tasmaniensis
Christinus marmoratus
Diplodactylus intermedius
Diplodactylus tessellatus
Diplodactylus vittatus
Lucaseum damaeum
Ningaui yvonneae
Mus musculus
Cercatetus lepidus
Sminthopsis murina
Apraisia inaurita
Delma australis
Delma butleri
Lialis burtonis
Cryptoblepharus carnabyi
Ctenotus brachyonyx
Ctenotus brooksi
Ctenotus regius
Egernia inornata
Egernia striolata
Lerista bougainvillii
Lerista punctattovittata
Menetia greyii
Morethia boulengeri
Morethia obscura
Tiliqua occipitalis
Varanus gouldii
Quail sp.
Southern Blind Snake
Peter's Blind Snake
Nobbi Dragon
Mallee Dragon
Central Bearded Dragon
Eastern Brown Snake
Coral Snake
Mitchell's Short-tailed Snake
Eastern Banjo Frog
Spotted Marsh Frog
Marbled Gecko
Southern Spiny-tailed Gecko
Tessellated Gecko
Wood Gecko
Beaded Gecko
Mallee Ningaui
House Mouse
Little Pygmy Possum
Common Dunnart
Pink Nosed Worm-Lizard
Southern Legless Lizard
Butler's Legless Lizard
Burton's Snake-Lizard
Wall Skink
Murray Striped Skink
Brooks' Skink
Regal Striped Skink
Desert Skink
Tree Skink
Bougainville's Skink
Spotted Burrowing Skink
Grey's Skink
Boulenger's Skink
Obscure Skink
Western Blue-tongue
Sand Goanna
A4.1
Parks Victoria Technical Series No. 59
Final Report 2002-2007
A4.2 Species within faunal groups captured at the Eastern Block,
Little Desert National Park, 2004-2007
The herptofauna groups are based on: Agamids (dragon), Gekkonids (geckos),
Pygopodids (legless lizards), Scincids (skinks) and snakes (families have been grouped
into one class).
Group Name
Scientific name
Common Name
Amphibian
Ctenophorus pictus
Painted Dragon
Amphibian
Pseudophryne bibronii
Brown Toadlet
Amphibian
Neobatrachus sp.
Spade-foot Toad
Dragon
Amphibolurus norrisi
Mallee Tree Dragon
Gecko
Christinus marmoratus
Marbled Gecko
Legless Lizard
Aprasia striolata
Lined Worm-lizard
Mammal
Cercartetus concinnus
Western Pygmy Possum
Mammal
Cercartetus lepidus
Little Pygmy Possum*
Mammal
Mus musculus
House Mouse
Mammal
Pseudomys apodemoides
Silky Mouse
Mammal
Sminthopsis crassicaudata
Fat-tailed Dunnart
Skink
Cryptoblepharus carnabyi
Carnaby's Wall Skink
Skink
Lamprophpholis delicata
Garden Skink
Skink
Lerista bougainvilli
Boulenger's Skink
Skink
Morethia obscura
Obscure Skink
Snake
Diplodactylus vittatus
Eastern Stone Gecko
Snake
Echiopsis curta
Bardick
Snake
Pseudonaja textilis
Common Brown Snake
Snake
Ramphotyphlops australis
Southern Blind Snake
Snake
Suta nigriceps
Mitchell's Short-tailed Snake
* Species only captured in the 2002 pilot prey species monitoring.
A4.2
Parks Victoria Technical Series No. 59
Final Report 2002-2007
A4.3 Species within faunal groups captured at the Central Block,
Little Desert National Park, 2004-2007
The herptofauna groups are based on: Agamids (dragon), Gekkonids (geckos),
Pygopodids (legless lizards), Scincids (skinks) and snakes (families have been grouped
into one class).
Group
Scientific Name
Common Name
Amphibian
Limnodynastes dumerilli
Banjo Frog
Amphibian
Neobatrachus sp.
Spade-foot Toad
Dragon
Amphibolurus norrisi
Mallee Tree Dragon
Gecko
Christinus marmoratus
Marbled Gecko
Legless Lizard
Aprasia striolata
Lined Worm-lizard
Legless Lizard
Pygopus lepidopodus
Common Scaly-foot
Mammal
Cercartetus concinnus
Western Pygmy Possum
Mammal
Mus musculus
House Mouse
Mammal
Pseudomys apodemoides
Silky Mouse
Skink
Ctenotus orientalis
Eastern Striped Skink
Skink
Lamprophpholis delicata
Garden Skink
Skink
Lerista bougainvilli
Boulenger's Skink
Skink
Morethia obscura
Obscure Skink
Snake
Suta nigriceps
Mitchell's Short-tailed Snake
A4.3
Parks Victoria Technical Series No. 59
Final Report 2002-2007
A4.4 Species within faunal groups captured at the Western Block,
Little Desert National Park, 2004-2007
The herptofauna groups are based on: Agamids (dragon), Gekkonids (geckos),
Pygopodids (legless lizards), Scincids (skinks) and snakes (families have been grouped
into one class).
Group
Scientific name
Common Name
Amphibian
Ctenophorus pictus
Painted Dragon
Amphibian
Neobatrachus sp.
Spade-foot Toad
Dragon
Amphibolurus norrisi
Mallee Tree Dragon
Dragon
Pogona barbata
Eastern Bearded Dragon
Gecko
Christinus marmoratus
Marbled Gecko
Legless Lizard
Aprasia striolata
Lined Worm-lizard
Mammal
Cercartetus concinnus
Western Pygmy Possum
Mammal
Mus musculus
House Mouse
Mammal
Pseudomys apodemoides
Silky Mouse
Mammal
Sminthopsis crassicaudata
Fat-tailed Dunnart
Skink
Ctenotus orientalis
Eastern Striped Skink
Skink
Lamprophpholis delicata
Garden Skink
Skink
Lerista bougainvilli
Boulenger's Skink
Skink
Morethia obscura
ObscureSkink
Skink
Triliqua rugosa
Blue Tongue lizard
Snake
Diplodactylus vittatus
Eastern Stone Gecko
Snake
Suta nigriceps
Mitchell's Short-tailed Snake
A4.4
Parks Victoria is responsible for managing the Victorian protected
area network, which ranges from wilderness areas to metropolitan
parks and includes both marine and terrestrial components. Our
role is to protect the natural and cultural values of the parks and
other assets we manage, while providing a great range of outdoor
opportunities for all Victorians and visitors.
A broad range of environmental research and monitoring activities
supported by Parks Victoria provides information to enhance park
management decisions. This Technical Series highlights some of
the environmental research and monitoring activities done within
Victoria’s protected area network.
Healthy Parks Healthy People
For more information contact the Parks Victoria Information Centre
on 13 1963, or visit www.parkweb.vic.gov.au