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

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Oct Nov Dec Jan Feb March April May Jun

Month

Avera

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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

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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

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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?