nankeen kestrel translocation program - aawhg · nankeen kestrel translocation project •the...
TRANSCRIPT
Nankeen Kestrel Translocation Program
Brisbane Airport
Wendy Weir
Nankeen Kestrel Translocation Project
• The Environmental Futures Centre at Griffith University engaged in 2010 (Prof Darryl Jones & Tom Nealson)
• Aims:
– To trial translocation to determine if it is a viable management tool for removing Kestrels
– To form possible management actions based on a population study
Nankeen Kestrel
• Small bird of prey
• Moderate risk
• Moderately abundant airside
• Hovers: predisposition to birdstrike
• Highest likelihood of strike
• In FY12 there were 20 confirmed strikes
• Strike rate has increased over time – recent La Nĩna cycle?
Trapping
• Bal Chatris traps used:
– 100 monofilament nooses on a wire cage
– Live mouse as a lure (animal ethics approved)
– Kestrel is snared around the foot or toe
Trapping
• Banding & Marking:
– One metal & two plastic coloured leg bands
– Coloured food dye applied to under tail feathers – lasts 6 months
Trapping
• From 21 trap sessions (Oct 2011 – June 12) a total of 94 kestrels were observed and 17 were humanely trapped & relocated (av. 122.5km distance).
• Only 2 returned.
Population Study
• Population study showed an increase in numbers from March to June, prior to breeding season in July: Peak season autumn to early winter
Average Kestrels Sighted per Month
0
1
2
3
4
5
6
7
8
Oct Nov Dec Jan Feb March April May Jun
Month
Avera
ge
Figure 1. Average number of Kestrels sighted per month at Brisbane Airport
(n=21)
Species Thresholds?
• Using data to develop thresholds for active management versus knowing when to step up active management
Figure 2. Average number of Kestrels sighted per month, with STD DEV
R² = 0.8369
0
1
2
3
4
5
6
7
8
Oct Nov Dec Jan Feb Mar Apr May June
Ave
rage
no
.
Month
Average no. kestrels per month
Average no. Low Moderate High Trend
March to
June – peak
season
Culling, Relocation, Birdstrike & Kestrel Sightings
• Between Oct 2011 to June 2012:
– 20 kestrels culled
– 15 kestrels killed by birdstrike
– 17 kestrels relocated
• The combination of culling, relocation and bird-strike has resulted in a total of 52 Kestrels being removed
• Significant population reduction for such a low density, territorial raptor
Culling, Relocation, Birdstrike & Kestrel Sightings
0
3
6
9
Oct Nov Dec Jan Feb March Apr May June
To
tal
Month
Kestrel Comparison
Total birdstrike total Culled
Total Reloc Average sighted
Culling, Relocation, Birdstrike & Kestrel Sightings
• Even though Kestrel numbers significantly increased between March and May, the combined management effort of culling and relocation helped suppress Kestrel birdstrikes during this period.
Going forwards
• Final phase of the trial to commence (Oct 2012 to June 2013)
• Honours student (Elliott Leach) to radio track kestrels on airport & monitor movements of relocated kestrels (survivorship)
• Relocation to continue:
– Fortnightly outside of peak season
– Weekly from March to June
• Do kestrels survive being relocated?
• Is relocation worth continuing?
Many thanks to Tom
Questions?