An evaluation of the surrogator™ Propagation System

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Dr. Jeffrey J. Lusk, Nebraska Game & Parks Commission
1
Outline
Captive propagation
 The Surrogator: What is it?
 The Pheasant Decline
 Objectives and Methods
 Results
 Conclusions
 Caveats

2
Captive Propagation
Dilutes genetic diversity
 Introduces diseases
 Low survival rate
 Reproduction lower among survivors
 Costly

3
The


Surrogator
What is it?
 Provides food, water,
shelter, and warmth
 Bobwhites & Pheasants

~$1800.00 + s/h
How does it work?
 1 day old chicks
 Minimum human contact
 Release pheasants at 4
weeks old
4
The


Surrogator
What is it supposed to
do?
 Keeps birds in “wild” state
○ Avoid predators
○ Improve survival
 Imprints chicks on a
location
○ Chicks stay in area
○ Available for later harvest
5
The


Surrogator
Does it work?
 Developers’ research
 Georgia study with
bobwhites
 ?????
6
12
The Pheasant Decline
6
4
2
Mail Carrier Index
8
10
1955-2007
1960
1970
1980
Year
1990
2000
7
Nebraska Surrogator Evaluation

Objectives
 Evaluate survival of pheasants after release
 Determine return to bag
8
Study Sites

2 Controlled Shooting Areas
 Jefferson Co.
 Gosper/Frontier Co.

2 Public Hunting Areas
 Sherman Reservoir WMA
 Sacramento-Wilcox WMA
9
Approach
Our approach was to deploy the
Surrogator system following the
instructions as closely as possible.
 We used multiple marking methods to
help insure Surrogator  birds were
identifiable among harvested birds.
 We radio tagged a subset of birds
placed in Surrogators and followed the
fate of these birds until the season
opener.

10
Study Methods
Select site for Surrogator
 Purchase rooster chicks
 Mark chicks with patagial tags
 Implant radio transmitters for survival
rate estimation on 20 birds at each site
 Mark all released chicks with
expandable, coiled leg bands
 Add chemical marker (deuterium) to
water for last 2 weeks in unit

11
Site Preparation and Set Up
12
Site Preparation and Set Up
13
Patagial Tagging
14
Radio Transmitter Attachment
15
Radio Transmitter Attachment
16
Leg Banding
17
Radio-tracking & Recovery
18
Aviary Study
Implanted 20 pheasants with radios
 Pheasants held in aviary at Sac-Wilcox
WMA
 Determine direct impact of surgery on
survival
 Banded birds to determine retention
 Most pheasants released prior to
hunting season

19
Harvest Wing Collection
20
Survival

Overall Survival from 30 July release
 For every 100 released pheasants, 14
survived until 25 October
 Of the 14 that survive, on average 6 would
be expected to be harvested
21
Survival
Site
Number expected to
survive until opener
per 100 released
Number of released birds
returned to bag (25 OCT – 31
JAN)
CSA1
18
1
CSA2
0
0
Sac-Wilcox
1
2
Sherman
27
3
22
Return to Bag

Return to bag estimated from harvested
birds with leg or patagial bands
 11.5% of reported harvest were marked
 Hunter bag returns were 5.4%
One banded bird was a late release from
the penned bird study
 Cost/pheasant = $36.21 ($3.50 w/o
Surrogator)
 Cost/pheasant returned to bag = $331.98
($32.14 w/o Surrogator)

23
Aviary Study Results
Pheasants implanted on 3 September
 3 pheasants died within week of surgery
 17 pheasants survived until 27 October
 14 of 17 surviving pheasants had both leg
bands
 2 surviving pheasants had one leg band
 1 surviving pheasant had slipped both leg
bands
 1 pheasant lost its radio

24
Conclusions
Survival rates were generally low at all
sites
 Retention of tags and radios was high
 Mortality from surgery in aviary birds low
 Return to bag of Surrogator pheasants
low

25
Caveats
1 year study
 Variability in survival among sites
 Transmitter effects beyond mortality

26
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