Gouldian Finch Erythrura gouldiae: downlist to Near Threatened
In 2000 the status was listed as EN C2a(ii) on the basis that the population size of this species
was conservatively estimated to be about 2,500 mature individuals at the start of breeding
season, with all individuals in the same genetic sub-population and continuing to decline
(Endangered: C2a(ii)). If the population was significantly fragmented, then no subpopulation indisputably contains more than 250 mature individuals (so could be C2a(i)).
In late 2010 an expert panel estimated all IUCN Red List parameters for this species based on
advice from local experts and published data. They determined that the most appropriate
status should be NT D1+2
The arguments are as follows:
Criterion A. Least Concern: past or future declines unlikely to be >30% within 3
generations.
Any decline that has occurred in the last 10 years has not approached 30%, nor is it
likely to in the next 10 years (3 generations is <10 years so 10 years taken as time
threshold for change). In fact both mean and median scores for population change in
the last decade were positive, while the median score in the next decade was for no
change while the mean was for an increase of 16%.
Criterion B. Least Concern: EOO and AOO too large to be considered.
Extent of Occurrence: well above all thresholds.
Area of Occupancy: The committee had estimated the Area of Occupancy as 10,000
km2, so above threshold levels, even taking into account that the birds are
concentrated at breeding locations in the late wet season and early dry season.
However new data have become available for this assessment since the expert
committee considered this criterion: Glenn Ehmke of BA has now analysed the
number of 2x2 km2 sites at which records of the finch have been made. The area
occupied within the area modeled as being climatically suitable on the basis of the
records (i.e. not vagrants) is about 1,000 km2. This is half the threshold of 2,000 km2
for species to be considered as Vulnerable under Criterion B2, assuming other criteria
are met. Notwithstanding this new data, the committee may still have determined that
the AOO was above threshold levels on the assumption that only some of the sites
across the landscape of northern Australia had been located.
Locations: the median and mean number of locations was 8, so below the Vulnerable
threshold of 10. However a plausible threat to these locations likely to happen in the
next 10 years was not specified given that decisions about each location are under
control of multiple managers and there is no record of the species disappearing from
any location in the last decade. For guidance on the definition of “location’ in the
IUCN Red List guidelines see Southern Cassowary.
Continuing decline: the committee felt a continuing decline in habitat quality was
occurring (not area or extent because AOO and EOO were not thought to be
contracting, nor the number of subpopulations or mature individuals). The committee
did not think that the population of mature individuals fluctuated by a factor of 10.
Criterion C. Least Concern: No continuing decline in the number of mature
individuals
While the number of mature individuals (2,500) was at or below the criteria for
consideration as Endangered or Vulnerable under C, a continuing decline was not
thought to be occurring. Therefore the structure or fluctuations in the population were
not relevant to listing under this criterion. In 2000 there was good evidence of
ongoing decline with disappearance from several sites within the previous decade.
Criterion D. Least Concern: The threshold for Vulnerable under D1 (1,000 mature
individuals) and the threshold for number of locations (5) were deemed to be
sufficiently close to the uncertainty of the data available that a status of Near
Threatened D1+2 could be justified.
Email discussions: Panel members are anonymous apart from two who only assessed
this species, and Stephen Garnett when acting as moderator
Don Franklin (Comments on the Northern Territory re-assessment of the conservation
status of the Gouldian Finch (Erythrura gouldiae))
The Gouldian Finch remains a contested and difficult case. On balance I’d stick with
Near Threatened but would be happy to consider a precautionary VU D1 pending
more thorough assessment of the Northern Territory populations. Below’s some
specific comments on various arguments that have arisen.
Nest site limitations
The work of James Brazill-Boast et al. on competition for nest sites, undertaken near
Wyndham, WA, is fascinating ecology. It is reinforced by a very recent publication
not specifically cited in any of the discussions (Brazill-Boast et al. 2011)
However, before James’ work is cited as evidence of vulnerability, I feel we need to
be clearer about what it does and does not demonstrate. Importantly, no evidence of
nest site shortages is presented – on the contrary, the modelling of nest niche
availability and occupancy in Brazill-Boat et al. (2010) clearly indicates that there are
far more sites available than were used by either Gouldian or Long-tailed Finches.
Indeed, in Brazill-Boast et al. (2011) the argument is not about nest site shortages but
about the consequences of interference competition at nests – nests with high rates of
interference competition fledged fewer young than those with low or moderate levels
of interference. Extrapolation of this to population status requires the assumption that
the production of young is a population-limiting life stage. Not only has this not been
demonstrated, but the field evidence (see, for instance, Woinarski & Tidemann 1992;
Franklin et al. 1998), collected during the mid to late dry season when most or all
young have fledged but few have completed moult into adult plumage, is that
juveniles comprise a very high proportion of the population. Large clutches and
multi-broodedness are a feature of Gouldian Finch reproduction (Tidemann et al.
2009). On balance, it seems most unlikely that productivity of young is a populationlimiting process. It would be good to undertake a PVA to further evaluate this.
The precautionary principle?
Sarah Legge has argued for application of the precautionary principle in the absence
of reasonable certainty. I’m quite sympathetic to that argument. However, Judit
Szabo tells me that the IUCN principles call for assessment on the current available
evidence regardless of previous status.
What status?
One can’t help but notice that Sarah’s comments don’t contain an argument about
which threatened classification and criteria the Gouldian Finch should/could fall
under. She seems to be leaning towards an argument that the species could be still
declining or is vulnerable to decline due to current threats. I can’t see this argument
standing (below), but feel that for the Northern Territory we should consider VU D1 –
population of mature individuals < 1,000.
Evidence of decline/stasis/increase
I’m inclined to agree with Sarah Legge that the evidence of increase is not
“compelling”. I agree that increased observer awareness has contributed to an
increase in sightings, but doubt that this is the sole cause. Indeed, the reappearance of
Gouldian Finches on the streets of Katherine, after an absence of several decades, is a
particularly striking piece of evidence of possible recent increase (recovery) in the
Northern Territory.
However, and as discussed by the Committee previously, the issue for classification is
not whether the species has increased but whether, in the last 10 years (3 generations
being < 10 years), the species has declined. I’m not aware of any evidence, even by
inference or suspicion, that could be interpreted as a decline during this time.
It is just possible that we’re seeing the upsurge phase of a long-term cycle, in which
case the Gouldian may decline in the future – and again qualify as threatened – but
this is highly speculative and no basis for our decision.
On-going threats
Sarah Legge has concentrated on environmental threats – fire regimes and grazing –
which I’ve long believed to be the real threats cf air-sac mite. The argument that the
assumed recovery is due to resistance to and/or a decline in infection rates of air-sac
mite can’t be ruled out, but must be regarded as speculative. An equally speculative
possibility is that localised improvement in fire management has allowed some
Gouldian populations to expand, potentially spilling over to other regions.
Regardless, Sarah is obviously correct that there are serious and widespread on-going
issues with fire and grazing in northern Australia. However, I am unaware that, in
areas relevant to the Gouldian Finch, that these have recently, or are likely in the near
future, to get substantially worse. The threats remain, but I see no evidence to suggest
that there is a inferrable risk of further decline as a result.
Population assessment
Population size under VU D1 is, of course, of “mature individuals”. Most (?all) large
flocks of Gouldian Finches contain a high proportion of juveniles and these need to be
discounted; otherwise, this can indeed “give a false impression of their numbers”.
There is some data on the proportion of birds that are juveniles in Woinarski &
Tidemann (1992) and Franklin et al. (1998) with proportions high but highly variable
(generally from c. 40 to > 90%). It would be good to obtain more and recent data
(from analysis of photos, or field counts). In the meantime, I’ll toss a generalised
correction figure of 80% of flocks being juveniles into the air for others to comment
on.
Sarah has flagged two seemingly good reasons why effective population size is less
than the number of mature individuals. They are:
 sex ratio heavily skewed to males
 reduced genetic compatibility between colour morphs (note, not
“incompatibility”). I’d further qualify this by pointing out that this has been
demonstrated as occurring in captivity but remains to be established as a
significant factor in the biology of wild populations
Judit Szabo informs me that it is acceptable, under IUCN guidelines , to incorporate
these factors and use effective population size as the ultimate measure.
Population fluctuations – Sarah has argued that these need to be taken into account. I
feel that it is plausible that the site fluctuations represent movements rather than real
fluctuations, and Sarah has elsewhere argued that the species is more mobile than
previously recognised.
Sarah has argued that the Gouldian Finch is “basically semelparous” and that this
makes it vulnerable to annual events. The latter may be true (but is there any
evidence of annual events causing severe fluctuations?), but the former is incorrect.
Although it is probably true that most Gouldians breed only for one breeding season,
it is not semelparous because:
 the species is multi-brooded (Tidemann et al. 1999)
 survival of adults beyond one year is low (Woinarski & Tidemann 1992), but
certainly not zero, e.g. Gouldian Finch Recovery Team banding database – I
have a copy)
Long-distance dispersal. The evidence for this hasn’t been published and I’d be
hesitant to read much into it at this stage. Nevertheless, contrary to Sarah’s
arguments, I believe that long-distance dispersal mitigates the effects of population
isolation and thus mitigates consideration of small population effects on effective
population size.
The question remains: what is the effective population size of the Gouldian Finch in
the Northern Territory. The truth is, we can at best hazard vague guesses. Given the
above, I think it plausible that it is less than 1,000, but on balance I’d suggest that it is
greater than 1,000. Given the IUCN guideline for use of the best current assessment
rather than a precautionary principle (influenced by past assessments), that’s an
argument for Near Threatened (D1).
Information gaps
The re-evaluation is a timely reminder that, even for such a well-studied species, key
information is remarkably scarce. For the Gouldian Finch this reflects, substantially,
that the key information is harder to obtain than a lot of other very interesting
ecological information that is tangential to a conservation assessment. Some priorities
for further investigation that seem do-able to me are:
 an evaluation of trends based on recent reports
 further estimation of the proportion of young in the population in the mid to
late dry season across a range of sites based on counts and analysis of
photographs.
 a PVA to identify critical life stages
 of course, on-going and expanded monitoring at key sites
Reclassification of the Gouldian Finch as Near Threatened may indeed undermine the
official drive to fund further research. Notwithstanding, the Gouldian Finch remains:
a. much more scarce than it was 50 or 100 years ago;
b. a public flag-ship species; and
c. (apparently) quite sensitive to land management and thus a good
environmental indicator.
References
Brazill-Boast J, Pryke SR, Griffith SC. 2010. Nest-site utilisation and niche overlap in
two sympatric, cavity-nesting finches. Emu 110: 170-177.
Brazill-Boast J, van Rooij E, Pryke SR, Griffith SC. 2011. Interference from longtailed finches constrains reproduction in the endangered Gouldian finch.
Journal of Animal Ecology 80: 39–48.
Franklin DC, Dostine PL, Tidemann SC. 1998. Post-juvenile moult strategies of coexisting Gouldian, Long-tailed and Masked Finches. Corella 22: 73-79.
Tidemann SC, Lawson C, Elvish R, Boyden J, Elvish J. 1999. Breeding biology of the
Gouldian Finch Erythrura gouldiae, an endangered finch of northern
Australia. Emu 99: 191-199.
Woinarski JCZ, Tidemann S. 1992. Survivorship and some population parameters for
the endangered Gouldian Finch Erythrura gouldiae and two other finch
species at two sites in tropical northern Australia. Emu 92: 33-38.
Sarah Pryke
Assessing the current status of the Gouldian finch
Unfortunately, this form (and process) is not suitable for assessing population
numbers of the
Gouldian finch. While the process obviously cannot be changed for one species, this
needs to
be taken into account when assessing its status. The Gouldian finch does not have a
'normal'
life-history, and together with the lack of systematic population sampling, this makes
it hard (if
impossible) to reliably estimate population size, change and distribution within the
constraints
of the criteria outlined in the assessment form.
There are a number of key points that I would urge the members to consider in
making a
decision on the status of the Gouldian finch.
1. Population size and number cannot be taken at face value from records during the
late dry
season (when all sightings occur). Much of this argument has already previously been
highlighted (by Sarah Legge and myself):
a) Most flocks are composed of high numbers of juveniles (8-12 times the number of
adults) and very low numbers of adults.
b) Juveniles have often started/finished moulting at this stage in the season and are
erroneously classified as mature adults.
c) Many (if not most) birds do not survive to the following breeding season.
d) Cannot reliably define independent ‘populations’ or ‘subpopulations’; Gouldians
are
highly mobile, moving hundreds of kilometres often within days to weeks (across
state
boundaries). For example, birds breeding in Wyndham (WA) have been found in
Newry
(NT) (well over 200 km apart and moved within a few weeks). Which ‘population’ do
they belong to?
e) ‘Population’ numbers fluctuate dramatically at the same site (from 0 to hundreds),
often changing within weeks; thus numbers cannot be summed across different
locations.
f) Similarly, sightings in new locations do not equate to new populations. While some
populations may have remained relatively stable (e.g. Yinberrie Hills), other
previously well known populations have disappeared (e.g. Timber Creek, NT, used to
be the place to see Gouldian finches, but they have not been sighted there for at least
7-8 years). Similarly, systematic searching showed that they are no longer found at
many other sites (> 60) where they were previously documented to occur in large
numbers. g) Most records are unsubstantiated sightings by birders, who often go to
extreme lengths to find and ‘hunt’ this very iconic species (I cannot stress enough
how unreliable many of these sightings are).
2. The number of mature adults does not reflect the number of breeding adults (i.e.
effective
population size). Non-breeding individuals are essentially redundant to population
estimates,
and this is obviously critical for the reliable assessment of threatened species. In
Gouldian
finches:
a) Adult males outnumber females (up to 1.9); thus up to a third of all mature adults
do not
reproduce.
b) Genetic incompatibilities between red and black morphs result in inviable
offspring; few if any offspring survive to sexual maturity.
c) Red-black pairs constitute 20-30% of breeding populations; thus effectively
removing
them from the breeding population.
d) Breeding populations are very small and highly isolated (because suitable breeding
habitat is limited, isolated and increasingly threatened).
The highest number of mature individuals in any one breeding population recorded to
date is
120 birds, but the reality is that the number successfully breeding will be substantially
lower
than this number. Although I'm very reluctant to put numbers on population sizes,
simply
because we lack the necessary data, this seems to be a central requirement for this
assessment
process. Taking into account effective population size (i.e. genetic inviability and sexbiases),
and using estimates based on the number of mature individuals sighted throughout
their range,
population size ranges between 600-2000 mature individuals. However, this estimate
is likely
to be highly inflated because it is based on extrapolation of numbers from dry season
counts
(problems highlighted above).
This suggests a very small population size of breeding Gouldian finches. I would
strongly urge
members to consider effective population sizes, not total population sizes, when
estimating
population numbers.
3. Although the lack of systematic data makes it difficult (impossible) to adequately
assess
population change (increase, decrease or unchanged) over the past ten years, there is
every
reason to suspect that populations are declining or at least are very likely to decline in
the
future. Published work of the Gouldian finches’ specialised life-history and ecology (a
publication list is provided below), suggest that this species is extremely susceptible
to further
declines:
a) Adult survival between years is very low (3-5%) and birds are semelparous (can't
seem to
set this parameter properly in the form).
b) Few juveniles (<8%) appear to survive and breed the following year.
e) Breeding populations fluctuate dramatically between different years (from 0-100
mature
individuals).
f) Most birds only produce 1 clutch per year; 19% will produce a second clutch.
g) Juveniles have an unusually long developmental period (dependent on parents for
at least
60 days), which limits the number of broods produced each season.
h) Gouldian finches are highly sensitive to environmental changes and stressors (e.g.
food
availability, competition); suffering high stress responses (hormone levels), reduced
health (immune suppression, air sac mite infestation) and often death when
environmentally challenged or stressed (e.g. during breeding).
i) The key threats invoked to explain their decline (fire, pastoralism) have increased
(not
decreased).
j) They have a specialised breeding ecology, which constrains optimal reproductive
success
and makes them highly sensitive to continuing habitat destruction.
• Diet: Reliant on a limited range of (increasingly threatened) seeding grasses
for
breeding; once this resource is depleted, birds abandon breeding. Despite nomadic
tendencies at other times of the year, breeding birds will only forage close to the nest
(results in small, isolated breeding populations).
• Nest sites: Obligate cavity nesters that have very specialised nest site
preferences
(often less than 30% of nest hollows within suitable feeding habitats provide suitable
nest sites). Nest sites are highly limited in the environment; intra- and inter-specific
competition (from dominant long-tail finches) limit the number of adults that can
breed within populations (up to 30-40% of populations) and reduces reproductive
output.
Together, the 'special' life-history of the Gouldian finch make it extremely susceptible
to
further declines. From what we are learning from increasing research, this bird is
probably in
much more danger than previously realised.
I appreciate that members are restricted to the form and guidelines set by the IUCN.
However,
if we cannot show that there has been any increase (and there is definitely no
compelling
evidence), and if we suspect that populations are currently or will further decrease in
the near
future, surely the most sensible action is to leave the Gouldian finches' status
unchanged?
Committee member
I agree regarding the 'data' on Gouldian Finch. I would add that its also one of those
species that people get very emotional about and that is when views can become
dangerously distorted.
Sarah Legge
I think the critical point is that we don’t know how the population is trending (but we
do have great cause to be concerned). A collection of non-systematic sightings is not
evidence of an increase (and – to counter that with a current anecdote – Gouldians
have turned up in a flock of a few dozen in the north Kimberley, where they are rarely
seen...you would interpret this as a sign of increase. BUT the bigger picture is that –
they’ve disappeared off Mornington. So I’d argue that they’ve simply shifted, in
response to a very unusual dry season. This has happened once before here, in 7 years
of monitoring.
The related point – you can’t safely use data from one site as an indicator of pop
trends – the scale of the sampling is not commensurate with the scale and erratic
nature of the birds’ movements.
I can’t reiterate strongly enough – we should not be using non-systematic birder
records, replete with all sort of biases, as evidence of population trends. GFs are
iconic – birders go after them like recreational fisherman go after the last few
flathead. Add those issues to the complexities of the GF’s long range movements and
bizarre life history....all of which scream “Red Alert”...
If we can’t say whether the population has increased, decreased, or stay the same,
why would we change the listing?
Panel member
Yes Sarah makes a good case. Should note, though, that the purpose of this exercise is
to determine the most likely data to feed into IUCN category determination, not
decide the category directly – we cannot redefine Endangered on the basis of one
species. We have actually been waiting for six years to see if numbers drop again but
they haven’t. While their biology is precarious, a bit like an antechinus perhaps, the
fall has not happened yet. Perhaps, however, people will want to wait a full 10 years
(since 3 generations <10 years) to see if the increased is sustained. I do agree the
identified threats of grazing and fire have not decreased but there have been no reports
of air sac mites by any of the current crop of researchers whereas the previous
generation (Sonia Tidemann, Don Franklin) could hear the birds wheezing when they
caught them.
Also the “bouncing” as you call it was not new: The following figure relates to
monitoring in the Yinberrie Hills near Katherine:
500
Population Estimate
450
Adults
Juveniles
400
350
300
250
200
150
100
50
0
1996 1997 1998 1999 2000 2001 2002 2003 2004
Year
Figure 2: Population estimates (with 95% confidence intervals) for 12 waterholes in
the Yinberrie Hills.
Committee member
The pattern of yo-yoing numbers, as shown from NT since 2003, remind me of what
we are seeing (or not seeing) in Regent Honeyeaters. We may have a couple of years
when almost none can be found, and then they appear in reasonable numbers at
several of their “regular” sites, only to almost disappear again. The same could be true
of Gouldian Finches, especially considering their large potential range, only sparsely
visited by bird watchers.
As well, we have a species at the r-selected end of the spectrum, as far as Australian
birds go. Clutch size of 5, with several attempts in a season, could mean that the
population can appear to bounce back after a good year or two. Then, give them a bad
year or two and mortality shoots up, and populations drop again.
Whatever figures we might care to put in the IUCN criteria, I remain to be convinced
that the major threats to Gouldian Finches, inappropriate fire, heavy grazing by cattle,
even nasal mites, have been alleviated. Add to this genetic compatibility among
different morphs, and problems of how we apply this to the idea of sub-populations
(arguably two totally sympatric sub-populations?), then there are simply too many
remaining unanswered questions to consider reclassifying the species. I would only be
swayed by a very convincing argument to downgrade Gouldians from Endangered to
Vulnerable (or further), and I cannot see that from the evidence provided. I don’t
think it looks good to downgrade a species from Endangered and then 10 years later
put it back up again.
I am quite persuaded by Sarah’s comments.
Panel Member
•
•
•
Last week the NT Government decided to advise their minister to list the species as
Near Threatened on the basis that the number of mature individuals may be as low
as 1500 but that the species does not meet other criteria for listing. At the meeting
at which this was discussed John Woinarski noted that in long term monitoring in
the Yinberrie Hills near Katherine since the mid 1990s that, while numbers have
fluctuated, with fewer in wet years when water more readily available, no negative
trend is apparent.
There is a photo from Kidman Springs Station in the Victoria River District taken
in November last year. It is part of a larger flock of about 350 birds. Apropos of
Simon Griffith and Sarah Pryke’s comments there is a high proportion of immature
birds in this photo as well as a good mix of red and black-faced birds that we now
know will not produce viable young (does that not mean they are separate
species?). So sheer numbers can be deceptive.
A few recent records from websites: 5/11/2010: Gouldian Finch [100+]
Copperfield Dam,nr Pinecreek. First seen next to road then dispersed into lightly
wooded areas away from road[road into copperfield dam about 500 mtrs before
2nd set of overhead powerlines] 100+ birds, mainly black -faced, some red faced,
some juvs. Great to see such a large number together as didn’t expect to see any on
this trip. 6/11/2010: A few flocks of 100+ [Gouldians] along the Victoria Hwy 24
km west of the VR road house, after Sandy Creek Bridge. Lots of feed and water
on the ground, saw many groups last weekend and in the late afternoon they were
tolerant of our presence allowing for good photographic opportunities. Many
juveniles and adults, black headed and a few red heads scattered amongst them.
Committee member
I believe they could be listed as VULNERABLE: C2b - based on: an estimated
population of mature individuals of less than 10,000; a continuing decline and;
extreme fluctuations in number of mature individuals. The cumulative impacts of
inappropriate fire regimes, grazing (and air sac mite?) and the polymorphism issue
detailed by Simon Griffith could result in significant declines.
John Woinarski
Gouldian assessment is difficult on many fronts.
It is a shame that we haven't yet analysed the recent years' monitoring data from
Yinberries. Although the methodology is susceptible to oddities of rainfall and
observer behaviours, it is still the best (well, maybe longest) long-term monitoring
data that are available.
The ultimate issue is whether one applies and is bound by the IUCN criteria
unreservedly. If so, then it is an almost impossible case to make it fit any threatened
criterion or category. There are too many birds, and there is no compelling evidence
of decline over the (short) relevant time period.
There is a bit of interpretative text in the v6.1. guidelines: "assessors need to consider
whether they have a precautionary or evidentiary attitude to risk (known as risk
tolerance). A precautionary attitude will classify a taxon as threatened unless it is
highly unlikely that it is not threatened, whereas an evidentiary attitude will classify a
taxon as threatened only when there is strong evidence to support a threatened
classification.
It is reommended that assessors should adopt a precautionary but realistic attitude,
and to resist an evidentiary attitude to uncertainty when appliying the criteria. This
may be achieved by using plausible lower bounds, rather than best estimates , in
determining the quantities used in the criteria."
So, this gives some licence to relax the criteria to plausible lower bounds, but even so,
I think the number of birds is too large.
I don't think semelparity should affect the application of criteria - we assess many
annual plants and e.g. northern quoll, and those criteria are appropriate. You can't
simply make up new criteria for different sorts of species.
But there is merit in Sarah's argument that the effective population size of mature
individuals may be less than the total number of mature individuals, given sex bias
and apparent incompatibility of colour morphs. We don't have good estimates of total
population size, or size of any sub-population; but even with a qualifier relating to
effectiness of popn size, there seem to be too many birds.
Let's focus on the criteria that it comes closest to: B2bc [assuming AOO applies to
breeding areas] and/or C1 and/or C2ai/b.
For B, I don't think we can demonstrate (or presume) b (continuing decline); and I
think a is out because it occurs at >10 breeding locations. ergo B doesn't fit.
C1 doesn't fit because the effective popn size is most probably >10,000, and we can't
demonstrate (or infer) decline over a 10 yr period.
C2 is the closest to fitting, but again requires continuing decline, therefore doesn't
make it.
I'd thought that there was some IUCN advice on moving down gears slowly, such that
you couldn't go staright from Endangered to not threatened, but I can't find that in the
guidelines.
Sarah Legge
Why the Gouldian Finch status should remain “Endangered”:

The information about GFs that is reliable clearly indicates:
 The lack of any compelling evidence for a population increase.
 That the key threatening processes identified for this species have remained
stable or have worsened.
 The extreme susceptibility of this species to further decline.
In contrast, we don’t have reliable information on population size nor trends, and the
interpretation of the pop size and trend information that we do have is fraught with
caveats to the point of abstraction.
 Finally, Gouldians have a highly unusual ecology, including an extreme life
history, which
 Makes application of the IUCN listing criteria inappropriate; and
 To the extent that you can address the criteria, you would need to modify the
estimated of pop size, fragmentation and trends to account for the Gouldian’s
life history.
For these reasons, I believe it’s essential that we apply a precautionary principle when
considering the status of the GF. Specifically, we shouldn’t delist a species (contra
the recommendations of the expert opinions of researchers currently engaged with this
species) simply because we lack the appropriate data to fill the IUCN criteria boxes.
Below, I set out the evidence that we have pertinent to each the main categories used
by IUCN. In compiling the summary notes below, I’ve drawn from research carried
out by:
 AWC – Australian Wildlife Conservancy, Kimberley
 NRETAS – VRD and Top End
 MQ – Macquarie Uni, Sarah Pryke and Simon Griffiths; Kimberley
 JCU – Rodrigo Esparza-Salas and Chris Johnson; northern Australia
Population size and trends
 Our current data do not allow us to estimate pop size nor trends either at, or
across, sites. Specifically:
 Population genetic assays across the species’ range (JCU), recovery of banded
individuals (AWC; MQ), observations of extreme local population
fluctuations in population size and age structure (NRETAS, AWC), and wing
morphology (AWC) all indicate that GFs disperse over very large distances.
Therefore:
 Pop estimates at a site may reflect changes attributable to the site, or
alternatively to areas within an undefined, but potentially very large,
distance from the site (ie immigration and emigration may be high and immeasurable), and can’t be used as a surrogate for the overall pop trend for
this species.
 We don’t have data from enough sites, censused simultaneously, to
consider estimating an overall pop size.
 Sightings of GFs at ‘new’ locations tell us nothing about the overall
population trend (they could equally well signify a diaspora from core
areas whose quality has dropped sufficiently to stimulate long distance
dispersal).
 Positive GF sightings are almost certainly increasing due to a higher
awareness, search effort, and improved communications. We have no idea
what the ratio of positive to negative sightings is. In contrast, a survey for GFs
at over 60 sites where they were abundant in the 70s showed them still be to
functionally absent (population have declined from thousand to one dozen;
MQ)
 All sightings are biased toward a time of year when GFs ‘mob up’, and thus
give a false impression of their numbers.
 An unknown number of sightings of large groups of juvenile birds have been
mis-identified Pictorellas

The issues above notwithstanding, there ere are rational arguments for why the
overall number of adult Gouldians should be reduced for the purposes of
assessment. These are:
 Many populations are male-biased (up to 1.9 times) (MQ).
 Genetic incompatibility of red and black morphs (MQ) make the population
sizes of the black and red morphs are 70% and 30% respectively.
 Pairing between red and black morphs lead to virtual reproductive failure and
reduced adult survival; the probability of such mismatched matings increases
in smaller populations, and the largest known populations of Gouldians
number around 100, making such events likely.

There is a rational argument for considering that Gouldians are distributed as
many small and isolated populations:
Although Gouldians are long-distance dispersers, when they are breeding, they are
confined to the area immediately around their nest hollows, and distributed as
many, small and functionally isolated populations. At this point, the issues
associated with genetic incompatibility come into play. In other words, at this

reproductive point in their life cycle, Gouldians are distributed as small, isolated
pops, despite their migratory habit at other times of the year.

There are rational arguments for why the population trend for Gouldians may still
be declining:
 Pop genetic analysis (JCU) indicates asymmetric migration from the
Kimberley to the Top End, and thus a source-sink phenomenon between entire
regions. This suggests the pop trend for the Top End is declining.
 The key threats that we believe caused the initial decline of Gouldians have
not been abated. Fire patterns are still an issue across most of the north, the
impacts of cattle and other introduced herbivores have increased, not lessened.
Other elements of biodiversity (like native mammals) are declining as a result
of the same threats. It would be illogical to think that GFs, out of all the
sensitive species, had suddenly become immune to these processes.
Generation time
 The GF is basically semelparous, making reproductive output overall pop size
extremely sensitive to annual events. (I don’t know why the calculator in the
spreadsheet sets the generation time of Gouldians to 2 years even when you define
inter-annual adult survival of 0%...)
Geographic parameters
 MtDNA analysis indicates a recent expansion of GFs from their origin in CYP
across the north to the Kimberley, in a time beginning 9000 and ending 3000
years ago. Microsat DNA analysis indicates asymmetric dispersal from the
Kimberley to the Top End, ie. The K is now acting as a source region (JCU). This
means that a decline in reproductive output in the Kimberley may very well first
be observed in the Top End!
Fluctuations and fragmentations
 At any one site, pop size fluctuates dramatically, by orders of magnitude (AWC
and MQ)
 The fragmentation of Gouldians during breeding has significant implications to
reproductive outputs because of genetic incompatibilities.
 The largest populations that we know of number around 100 adults, and the
number breeding successfully will be substantially smaller than this.
Donald Franklin
As you may recall, Stephen, I argued >10 years ago that EN was an overstatement.
Intuitively, LC is now a gross and unsupportable shift in the opposite direction given
small numbers, patchy distribution and demonstrable vulnerability to land
management practices that are near omni-present in its range. However, having gone
through the criteria with Judit, it does seem that the criteria let this species down.
However, I do feel that the stated reason for change is unsupportable and needs
modification. Where is the evidence of an increase (OK, no decrease, but an
increase?)? Is this based on more than sightings on the Mary River and in the VRD?
One can generate equally plausible alternative explanations for the recent rash of
sightings in these populations in terms of local shifts (VRD especially has strong case
for being no more than a local shift – we could find hundreds at Timber Creek 15-20
years ago). Unless the rash of sightings is occurring on a much wider scale, I believe
interpretation of an increase is not sustainable. Are waterhole counts in the Yinberrie
Hills, Newry and in the Gulf country showing a major increase? If they are, then I’d
be convinced.
Waterhole counts stay steady but local populations in those areas also probably
steady. There have been more sightings in Qld, particularly S of Lawn Hill and a
scattering through CYP. They are seen at more sites in the Kimberley but poor;ly
documented as you suggest. If it is OK we shall include your views in the data pack
we send to the panel.
Sarah Pryke
As I think you are aware, I’ve been working with the Gouldian finch in the eastern
Kimberley area. I started around Wyndham in 2007 and have steadily expanded out
into others areas, so that I now work with populations around Wyndham, Kununurra
and Halls Creek (mainly in the areas between these three places). This does cover a
big area and I (and students) have systematically searched large parts of it for
Gouldian finch breeding populations. There are now 8-12 decent populations
(depending on the year can have 0-120 adults breeding), usually varying in size from
40 to 120 adults and across multiple sites (3-20 km apart), with each of these
populations isolated by at least 40-50 kms.
Overall, I agree that there is a perception that Gouldian finches have increased, but
unfortunately I’m not convinced that there is the empirical data to back this up at this
time.
This is based on a number of (often interacting) reasons from the work that I’ve been
involved with. This includes:
1. Mobility and range
As you are no doubt aware, the Gouldian finch is classified as Migratory
(Environment Protection and Biodiversity Conservation Act 1999) and has two quite
distinct life-history stages – breeding and non-breeding – both of which are linked to
quite different behaviours and habit use by the species. During breeding (Feb-July),
the birds utilise open woodland areas (usually ridges) dominated by cavity bearing
trees (e.g. Eucalyptus, Corymbria) and seeding grasses at this time (e.g. sorghum,
spinifex). The birds occur in small colonies (which is probably an artifact of the small
patches of available nesting habitat in a larger area) and seem to move relatively small
distances (1-10km) to feed and water. However, once feeding resources become
depleted (usually by June-July), the birds leave the breeding habitat and move to
lower-lying areas (which contain a number of different seeding grasses at this time),
forming often very large flocks with other finch species (hundreds to thousands of
various finches) and begin moving across the broader landscape in search of food.
The reason I’m highlighting this is because it is only during the late dry season (nonbreeding) time when the Gouldian is sighted in large numbers.
There are a few problems with relating these sightings to total population sizes.
A. Inaccurate sightings: In last few years, I have heard a few reports of ‘a thousand
Gouldians’ sighted at a few different locations. In three cases, I actually went with the
people to see all these birds. In all cases, Gouldians made up a small number (less
than 70 adults) of these sightings. For example, last month I went to Keep River
National Park (NT) to see ‘thousands of Gouldians’ and despite the man insisting that
there were thousands right in front of my eyes, there were only 20-25 adults and about
100 juveniles – the rest (yes, thousands) were mainly juvenile pictorellas (which
admittedly do resemble juvenile Gouldians). Obviously, there are a number of reliable
reports (and expert people), but I would definitely caution reading too much into any
unconfirmed sightings.
B. Mobility of the species: Using unique combinations of colour bands and intensive
searching for birds through the larger area, I would definitely say that this species
appears to be highly mobile during the non-breeding season (this also seems to fit
with previous records from Mornington and other reports (NT Parks & Wildlife from
the early 90’s). In fact, three coloured-banded juveniles that I sighted in a flock near
Wyndham in early September this year I subsequently found 2 weeks later at Newry
in the NT (more than 250 km away – I definitely double-checked the bands many
times!). Importantly, although good numbers of birds were recorded during the annual
September count around Wyndham this year (about 850 birds, 110 adults), they all
completely left the area such that two weeks after the count there were no Gouldians
at any of the monitoring sites (and we hadn’t done any banding at any of these sites).
Instead, birds were subsequently found at Newry, even though when I’d been through
during late August I couldn’t find a single Gouldian finch there. I have heard similar
reports from other places (such as Mornington?) where large numbers of birds are
recorded one year, but absolutely nothing recorded the next year. More work and data
is definitely needed on the dispersal of this species. However, it does highlight that
the bird can and does move large distances. The problem is that the flocks of
Gouldians that are been reported may often be the same flocks, just in different areas.
Unfortunately, none of the current (e.g. Wyndham, Mornington) or past counts (e.g.
Yinberrie, Newry) have been done at the same time (all are sequential) so we have no
idea of the extent of this problem. However, given the distance that the same group of
birds can move (250 km), I think that caution is needed when interpreting all
sightings, even across different states, as independent.
C. Moved into new areas: Gouldian finches have been sighted in a number of areas
that they were not previously recorded. This is perhaps not surprising given their high
mobility and that fact that many areas are becoming increasing disturbed (e.g. cattle,
fires, mining developments, etc.). Although this may give the perception that their
numbers and range have increased, I think we need to be cautious here. First, once
again, these sightings are of birds during the late dry and early wet (non-breeding
season) when they move large distances. I am unaware of new range expansions in
breeding populations (which are obviously fundamental for the recruitment of
juveniles and the persistence of the species; see below). Second, Gouldians are often
no longer located in areas that they used to inhabit. Although a number of populations
have largely (but not always) remained in a few well-known places (although this has
often not been properly evaluated; e.g. Yinberrie Hills in recent times?), they have
disappeared from others. For example, last year I went through the Kimberley (east to
west) and western NT with some old finch trappers who took me to over 60 sites
where they used to trap Gouldians about 20 years ago in large number (one site they
took out over 3000 Gouldians in one morning, which was rather sickening). However,
during the whole three weeks we only found 12 Gouldian finches (3 adults, 9
juveniles). Most of these areas, which they described as been pristine habitat ideal for
Gouldian finches are now heavily degraded (by cattle, fire and increasing agriculture
and mining development). Overall, I think we need to be very cautious of interpreting
sightings in new areas as range expansion until empirical work is done to show that
this is the case.
2. Population size
Currently, the Gouldian finch is estimated to have a total population size of less than
2500 individuals with no one population containing more than 250 individuals. While
these exact numbers may or may not have been accurate in the past, I don’t personally
know of any individual population at the moment that contains more than 250 mature
adult individuals (and definitely none that contain more than 1000 – I wish!).
A. Breeding populations: I have intensely searched large areas (hundreds of km’s) to
locate and work with significant breeding populations and the largest population that I
have found is about 120 adults (as described above). I not aware of any other work
been done on breeding birds and unfortunately there has been very limited work done
in the past (e.g. Tidemann et al. 1992). It’s definitely not easy. But there are also very
few populations, even in what is often considered to be ideal breeding habitat, simply
because either the required grass species are not present (for feeding) or the trees
don’t contain suitable tree cavities (for breeding). Because population size is
measured by the number of mature individuals at breeding, especially for individuals
that may lose a subset of mature breeding individuals (see adult mortality below), this
means that most populations are likely to be much smaller than those currently
estimated (and especially from water counts during the non-breeding season).
B. Non-breeding populations: Gouldian finches are reported in large numbers during
the non-breeding season, for example, around our main site near Wyndham, most
years we locate about 600-900 individuals during the annual count, which is
considered to be one of the largest known populations (although I’m guessing
Mornington has more?). However, adults make up only a small percentage of the total
number of birds reported. This varies slightly between years and populations but
juveniles far outnumber adults at about 7-12 juveniles for every 1 adult. I have found
similar numbers in other areas during the non-breeding season, including populations
found near Halls Creek (WA), Kununurra (WA), Argyle Diamond Mine (WA),
Newry (NT), Timber Creek (NT) and Victoria River Station (NT). Therefore,
although large numbers are often reported, the effective population size is only a
fraction of this and I would be very cautious in interpreting large population sizes as
the number of mature individuals (which is needed for assessing status). None of
these populations that I work with have more than 250 adult birds (180 is top estimate
for adult birds within one population recorded over the last four years).
C. Sex-biased populations: Another factor that affects effective population size is the
ratio of males to females, since the number of breeding females determines population
size and growth. In the populations I’ve been working with there is a male-biased sex
ratio, with males out-numbering females by 1.4-1.9. Similar male-biased sex ratios
have also been reportedly previously from other populations (e.g. Newry; Tidemann
et al. 1992). Therefore, not every adult in a population will reproduce and the
effective population size can be substantially lower than the actual number of mature
individuals (which again affects estimates of the total population size).
3. Viability of populations
Another factor that needs to be accounted for is the potentially high adult mortality. I
have been colour banding birds for the last four years (adults and juveniles in the nest)
to try and get dispersal and survival data. In the last few years, very few adults (less
than 2%) have returned to the breeding areas and the big question is whether they
have dispersed or died. Although they may have dispersed, especially given the high
mobility of the species, it is the juveniles, not adults, which I’m locating in different
populations. For example, the three birds moving from WA to NT were all juveniles,
and all movement records to date for distances further than 50 km (59 birds) are for
juveniles. It is possible that adults may be dispersing to different areas (that we
haven’t located) but no adult-only or adult-biased populations have ever been
recorded (during the non-breeding season).
Potentially, most adults do not survive for long. Some recent work I’ve done on
captive populations shows that the red and black head-colour morphs are genetically
incompatible and interbreeding between them results in very high offspring mortality.
Similar effects are also found in wild populations, with red and black parents
producing fewer fledging offspring (2-3) than red-red and black-black parents (5-6).
These incompatibilities don’t just result in offspring mortality; they also result in high
adult mortality and make birds very susceptible to the effects of stress. In the last four
years, 21 dead Gouldian finches have been located, either dead on the nest (17) or
lying in the field (near water; 4). During this time, no other dead finches were found
(despite monitoring nests of the much larger breeding populations of Long-tail
finches).
A potential concern is that this is largely an annual species. Although a few wild
individuals have been recorded to live for a number of years (3-4 years), it may be
that most individuals don’t live more than one breeding season. In captivity (with
favourable conditions), most individuals don’t live for more than 2-3 years, and
genetically incompatible birds don’t live beyond a year. In reality, this means that
each year the population is largely dependent on offspring recruitment from the
previous year, which makes the species highly susceptible to any environmental
fluctuations between years. This is obviously an area that needs more study, but
potentially may have a large impact on the persistence and future declines of the
species.
As a side note, I’ve also recently been doing some modelling of populations (with a
mathematical modeller obviously) to try and understand the coexistence and
continued persistence of red and black morphs. By incorporating all of the
information on the species some interesting trends have emerged. In particular,
population size is fundamental to the long-term coexistence of not just the morphs
(which I realise is not of interest when assessing the status of the bird), but also the
species, as small populations, purely by chance, have higher interbreeding between
the morphs (leading to higher genetic problems) and often go extinct. This is despite
the model allowing all birds in the total population to mix before splitting into smaller
populations for breeding. Although reliable empirical data is pretty scarce, there
seems to be fewer red females reported in many populations, with red males often
breeding with black females. In the populations I work with 20-30% of breeding birds
are mixed morph (red and black parents). Genetic instability is obviously a long-term
concern that should at least be considered.
4. Fluctuations in range and numbers
As described above, the range of Gouldian finches can change substantially (e.g. nonbreeding populations at Wyndham [and Mornington] that varied from 0 to 800 total
individuals (including juveniles) between years). This may be related to the large
mobility of the species, but also suggests that there may be large fluctuations in range
between years. Breeding populations also fluctuate markedly between years, on
average (across 12 populations) from 7 to 82 breeding birds within a population
between 2008 and 2009. This 12-fold increase suggests that there is either
considerable variance in population growth or in habitat preferences. Since these birds
were not located in other surrounding breeding habitats or populations (within 100 km
radius and considerable search effort), such variability can affect long-term
population viability and extinction risks.
5. Continued habitat degradation
In the recovery plans for the Gouldian finch, habitat destruction is highlighted as the
major cause for the decline or lack of recovery of the species. A number of
management measures have been suggested (e.g. removing cattle, controlling
wildfires), but as far as I am aware, Mornington (WA) is the only place that has
significantly rehabilitated the habitat and subsequently monitored Gouldian
populations. In other areas, it appears that habitat destruction is a continuing and
increasing problem. Searching for Gouldian finches increasing requires moving into
National Parks and conservation lands (with management programmes to control or
minimise threats) and few Gouldian finch populations seem to be found outside
conservation areas or in disturbed habitats. Since there has been little attempt to
recover Gouldian finch habitats and habitat destruction is largely continuing (at least
where I am in the eastern Kimberley and I suspect in many other area) it seems that
the current threats to this species are still present, and may be increasing.
OK, I should stop now and send this as I won't get another chance before the end of
the week. I hope this makes some sense. Unfortunately, most of it is not published at
the moment (but some at least is or will be written up soon).
Overall, I think that there is a perception that Gouldian finches have increased. This
may, at least in some small part, result from the increased publicity about Gouldians
in the last ten years. For example, AWC, and especially Mornington, have done a
brilliant job of raising the profile of this species. I know many people go all the way
there just to see the bird. Other agencies, such as WWF (e.g. Threatened Species
Network), and the media have probably also contributed. Together, this has raised the
profile of the species (which is great) and more people are looking and sighting it in
the wild (especially because the locations of good populations are becoming
increasingly well known).
However, for the reasons I have detailed above, I’m not convinced that there is
sufficient evidence at the moment to change the threatened status of the Gouldian
finch. Whether or not they are declining, I’m not sure (from four years worth of data
that’s a hard call). But from the available empirical data (that I’m aware of) I'm
definietly not convinced that they have increased, as this species still appears to: 1)
occur in small subpopulations; 2) has large fluctuations in the number of mature
adults; 3) has large flucuations in the extent of occurrence, number of locations and
subpopulations; and 4) the cause of reduction has not ceased.
I really hope that the Gouldian finch can be removed from the threatened list
sometime in the near future, but I think it would be premature to do so at this stage
without robust empirical evidence that the species is increasing. Hopefully, work in
the next few years will fill in many of the gaps in our knowledge.
Ian Gynther
This seems like a drastic and rapid change from EN to LC. While I don’t dispute the
population is now increasing across much of its range, how big exactly is a
‘population well in excess of 1,000 individuals’? When assessing species considered
near threatened in Qld we have adopted the following for NT D1: Population size less
than or equal to 3,000 mature individuals. Would the Gouldian Finch population
nationally be 1,000< n <3,000? If so, it might be more prudent (and less eyebrowraising for readers, the public, etc.) to list the species as NT D1, at least until the next
review of its conservation status takes place and more quantitative data are available.
Committee member
change from EN to LC is pretty impressive. Have the underlying threats
(inappropriate burning, nasal mites) really been overcome? Or is it being a typical
boom-bust species which after a lot of bust is showing a (temporary?) boom due to a
favourable season or two?
Sarah Legge
The annoying thing about this process is that the IUCN criteria for listing are very
specific and constrained, and are largely geared towards providing evidence of
continuing decline (as opposed to evidence of vulnerability) and are framed to
consider a very ‘average’ species in terms of life history etc. So although you and I
categorically know that it’s ridiculous to delist the GF, much of our information
actually confirms their vulnerability (bec of bizarre life history, the fact that the
threatening processes have worsened not improved, the fact that there is NO
compelling evidence of pop increase)...however none of this information shows
continued decline. It’s a subtle but important point, and personally i think it’s a stupid
‘hole’ in the listing criteria. Our own EPBC process is better in this regard, because
although the listing criteria are similar, there is an explicit recognition of the need for
a precautionary approach, delisting places the burden of proof on the delisters (so in
this case, one would need to prove GFs were out of the woods, instead of, as in this
case, we are needing to prove they are still in the woods), and also elbow room for the
minister to exercise sensible judgment (rather than being straight-jacketed by the
criteria).
Having said that, I still think we can make a case. So if you don’t mind, I might run a
few things past you later next week, for your input.
Simon Griffith
It is with some concern and surprise that I hear that there is a suggestion that the
status of the Gouldian Finch is to be reviewed and may no longer be considered as
endangered. Although Sarah Pryke, with whom I work, has already written a detailed
response about some specific points I would like to also make a submission that I
would appreciate if you can bring to the attention of the relevant committee. This
submission covers largely separate ground from that prepared by Sarah and reflects a
number of technical concerns that I believe are very pertinent to any discussion on the
matter.
I have attached the text as a PDF but also copied it in below. I would be extremely
grateful if you are able to consider this and present it in whole or part to those
responsible for making any evaluation.
Since the Gouldian finch was first listed as endangered, whilst there is an increased
community awareness of the species and a spate of reports of good sightings in the
media and birding communities, there is no scientific data that I am aware of that
supports an increase in the overall population.
The only real good news story concerning this important species is that in the past 7
years there has been a dramatic increase in attention and money spent on it through
the three following initiatives.
 Save the Gouldian Fund was established and has invested over a million dollars in
acquiring reserves and funding basic research into the biology of the species in an
effort to reverse the decline.
 The Australian Wildlife Conservancy has invested significant resources in
highlighting the plight of the species and landscape in which it lives and has
conducted intensive research work on the ecology of the species, particularly at
their important Mornington Station.
 Our research group based at Macquarie University has focused significant
attention on research into the evolution and ecology of the Gouldian finch, funded
by a high level of ARC funding (over $2.5 million in the past 6 years).
All of these independent initiatives now mean that the Gouldian finch is the subject of
more research than at any time in the past (the research is more intensive in nature,
involves more personnel and organisations, a broader scope and covers a larger part of
the range than previous work in the Northern Territory). Whilst the fruits of all this
work have not all been published at this time, we are currently better able (than in
1989) to assess the problems that led to the decline and understand the limitations of
current knowledge and our ability to accurately determine the current status of the
species.
As detailed by Sarah Pryke (and probably also Sarah Legge who also has an excellent
and independent first hand knowledge of the species), I believe that our confidence
about the status of the species should now be lower than it was when it was assessed
in 1989. The best data based on intensive work at Mornington, WA (AWC),
Wyndham, WA (Macquarie University), corroborates earlier work at Newry (NT),
that the species is highly mobile and even in these areas the numbers fluctuate
significantly from one year to the next.
More importantly, through our research into the evolution of polymorphism in this
species we have indentified (in 2009) a number of very significant and previously
unknown threatening process, that have the potential to seriously exacerbate the
further decline of the remaining fragmented populations.
The polymorphism of the species was more or less ignored by work up to the original
listing (in 1989) (or at most was mentioned as an interesting aspect of the species).
Through very careful breeding experiments in captivity, and the application of
molecular techniques we have demonstrated that when a female breeds with a male
with an alternate head colour to herself (i.e. a red-headed female paired to a blackheaded male or vice versa), the genes are largely incompatible and the same genetic
problems occur that are seen in hybridisation. 40% of males offspring and a
staggering 80% of female offspring die within three months of hatching, due to
genetic failure. This result was published by a paper in the journal Evolution in 2009
and our further work on this phenomenon has been published in two subsequent
papers in the top-ranked journal Science. i.e. this is an important and very real
problem facing the species.
Whilst we believe that this basic genetic incompatibility between the red and black
morphs has probably persisted for at least the past half million years (we are currently
engaged in further genomic work to clarify the basis of the phenomenon), the problem
is seriously exacerbated by dwindling population sizes. Before the recent decline
when individuals bred in populations numbering thousands of individuals, it was
likely that most red-headed females would be able to find and breed with a red-headed
male. Today, most individuals have to breed in much smaller populations. If there are
only ten males locally available then the opportunity to find a correct male is lessened
and there is a higher probability that some breeding pairs are reproducing but
producing these genetically inviable offspring. We are currently working to model the
extent to which this genetically based process could accelerate the decline and hinder
any recovery of the species. This threatening process is based on the characteristic
genetic architecture of the polymorphism of this species and will mean that population
fragmentation (which we already knew to have occurred) could be a more significant
threat for this species than many others.
An interesting and related issue is that our findings that the red and black form are
largely genetically incompatible indicates that to a degree the Gouldian finch is
somewhere between a species, a sub-species, or even two separate species
(interestingly they were first described as two separate species and the controversy
raged for a further 60 years until they were unified into a single species based on
erroneous data in 1879). We are currently clarifying the exact nature of the red and
black headed forms by determining the extent of divergence and introgression of the
two genomes (at least part of which is clearly distinct). This genetic status of the
Gouldian finch poses some very interesting questions for conservation biology (we
are preparing to publish this). To save the Gouldian finch we really need to save both
forms. However the effective population size of the two forms is obviously
significantly smaller than the total population as, for example, the red genome is
actually only represented in about 30% of the total population (because that is
typically the frequency at which they tend to occur). Any consideration of the status
should consider this important point. Even if there are currently 2500 individual
Gouldian finches in the national population in the wild, that means there are likely to
be only 825 copies of the red genome (a significant cause for concern).
We have also recently identified a complex frequency dependent competitive
interaction between red and black forms that explains the relative stability of the
70:30 ratio of red to black birds. We have shown recently (through both mathematical
modelling and aviary based population experiments) that when this balance is
perturbed reproductive success is reduced across the whole population. Again this
complex ecological dynamic has only just been identified and could be a major
threatening process.
In summary, in the past 6 years our research group have published over a dozen
papers in the scientific literature, doubling the total amount of scientific publications
focused on the Gouldian finch. Through that work already published we have
identified a number of major threatening processes that were not even remotely
considered for this species at the time of the original listing. These findings and the
heightened understanding of some basic ecological parameters as identified by other
recent intensive work by ourselves and AWC suggest that the Gouldian finch could be
in far more serious trouble now than at the time of the initial listing.
It would be extremely premature to remove the endangered status of this species at
this time given the amount of intensive research that has occurred in the past seven
years. The work that ourselves and AWC have in preparation, in addition to a
consideration of the recent findings that we have already published (and outlined
above) highlights the increased threats to the species and is likely to make any
downgrade at this time seem very premature.
I reiterate again that the most positive news about this important species is that finally
it has become the focus of high profile and international scientific attention of broad
focus that is helping to elucidate the nature of the species and some important
questions about its population genetic structure, its mobility, life-history and ecology.
I imagine that in about 5-10 years we will be in a decent position collectively to
properly assess the vulnerability of the species (in all its forms) to extinction, but at
this time I do not feel we are any nearer than in 1989.
Stephen Garnett
Our provisional assessment as Least Concern has drawn some reasonably strong
responses from those who continue to have grave concerns for the species. Sarah
Legge has the most intimate knowledge amongst the committee and I hope will be
able to contribute. Work by her and her colleagues show how vulnerable this species
is to overgrazing and, to some extent, fire.
However birdwatchers in the Northern Territory feel they are seeing the species far
more frequently than in the 1990s or early 2000s. Certainly through the 1990s the
species still seemed to be dropping out from known sites, such as Timber Creek in the
NT and Cumberland Dam in Queensland but, since about 2003, there seem to have
been a remarkable number of sightings in the NT at least, and a surprising number in
Queensland with records of small flocks at two sites on Cape York Peninsula in 2008
(I think) and several new records in western Qld including about 60 NW of Mt Isa this
year.
The NT govt. site shows a distribution across the NT up to 2006
http://www.nt.gov.au/nreta/wildlife/animals/threatened/pdf/birds/gouldian_finch_en.p
df
And these are roughly the position of birdwatcher records 2003-2010 – almost all
records are from main roads and birdwatchers seem to go to the same places and
largely during the dry season. Virtually all records are dominated by immatures.
Begging juveniles may indicate breeding nearby but were recorded only near
Maningrida in the north-east.