In the last week of October GFN and the AWSG spent a week catching shorebirds for the EAAF satellite transmitter project. Catching started off very well with all the Great Knot that we needed being caught on October 22nd. 20 of these birds were taken in to captivity for an experiment in to their ‘personality’ in line with work by Bijleveld et al 2014.
We had difficulty to catch the required Bar-tailed Godwits we needed, but on 29 October we finally made a very nice catch despite one cannon malfunctioning and not firing. The catch contained lots of adult female Bar-tailed Godwit, the age and sex we were wanting for the satellite project. No Bartailed Godwit were used for the personality experiment. Knots are relatively easy to keep but godwits are not. The Bar-tails were given their satellite transmitters at the catch site and released immediately.
The catches gave us some long-lived individuals (note that e.g. 13+ means the bird is a minimum age of 13 and may well be older). We caught a Red Knot age 16+, Curlew Sandpiper age 13, Great Knots age 19+, 18+, 16+, 15+, 14, 12+ and one at 13 years old that is now carrying a transmitter. Bar-tailed Godwits age 19+ and 14+ the 19+ bird is carrying a transmitter. And a Pied Oystercatcher aged 15 years old.
The Great Knots really rather enjoyed captivity after a day or two of adjustment and with fresh water and meal worms on demand they did very well.
The short experiments went smoothly and the video footage of their time in the experimental tent will be analysed by Ying Chi Chan as part of her PhD.
The transmitting birds are already giving a wealth of information, some new and some backing up our perceived knowledge of how these two species use the bay during the non-breeding season. Two of the Great Knots surprised as to differing degrees. One moved to 80 Mile Beach 165km south west of Roebuck Bay, a slight surprise but we know from colour-band resightings that a few birds do this. This bird has just in the last few days moved 50km south along the beach. It will be interesting to see if it was an ‘explorer’ in the experiment, from a quick view of the video footage it would appear so!
The other one surprised us considerably more as it suddenly decided to take off and fly directly to the eastern side of the Joseph Bonaparte Gulf to a mudflat and river mouth at Hyland Bay in the Northern territory. This is 912 km in a direct flight from Roebuck Bay but we know that the bird flew along the coast as it was transmitting during some of the flight, so it probably did over 1,00km to get to its new ‘home’. The obvious questions spring to mind, will it stay there (google earth and information from Ray Chatto tell us the area is perfect for knots, undisturbed with large inter-tidal mudflats.) If it migrates north successfully will it return next September to Roebuck Bay or straight back to Hyland Bay?
The transmitting Godwits have been less adventurous with very regular trips, mostly on night time tides, 30km south from the northern shores where they were caught to Bush Point in the south of Roebuck Bay.
We wish the birds the best of luck with their future carrying their transmitters with the endurance test of north and southward migration and breeding ahead of them.
Those of you working along the EAAF please keep an eye out for them and report any you see!
This work is being conducted under permit numbers:
Federal Banding Authority 2184.
State Permits, Regulation 23 – BB 003299, Regulation 17 – SF 010075 and SF 010074, Regulation 4 – CE 004238.
A summary of the catches is in tables below.
And then a selection of images.
So don’t stop here!
Thanks, as always go to BBO, Broome Volunteers and the local office of DPaW and the licencing division of DPaW, they are very helpful and very efficient (not words always associated with Government Departments!)
And special mention for this particular project go to Grace Maglio, Helen Macarthur, John Curran, Kerry Hadley, Maurice O’Connor and Liz Rosenberg.
Chris Hassell, Ginny Chan, Lee Tibbitts and Theunis Piersma.
December 29 2014
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