Salinity levels in The Coorong trigger Banded Stilt breeding…



A lack of freshwater over several years has produced salinity levels in the south lagoon of the Coorong similar to those in playa lakes such as Lake Eyre, Lake Torrens and Lake Frome, when occasional flood conditions bring water to them.  For the first time on record we have witnessed brine shrimp numbers in the south Coorong that were sufficient to trigger the breeding cycle of the Banded Stilt.  These birds which have previously bred only, when the playa lakes in S.A. North Eastern deserts are in flood (last in 2000), are now breeding in the CoorongÕs south lagoon.  Whether this marks a permanent change in the ecology of the southern Coorong, or whether it can recover to a less saline ecology remains to be seen.


Over the Feb 4th and 5th weekend the Australasian Wader Studies Group of Birds Australia conducted the annual shorebird population count over the whole length of the Coorong.  On Saturday I spent 8.5 hours in a fishing boat with 3 others including the fisherman counting shorebirds from Parnka Point to a point opposite Fat Cattle Point on the Younghusband Peninsula.  We counted mainly Red-necked Avocet, Sharp-tailed Sandpiper and flocks of Banded Stilt from 20 birds up to about 8,000 birds.  We also counted hundreds of Banded Stilt chicks about 1 to 3 weeks old swimming in small ÔcrechesÕ of about 9 birds, or individually and spread right across the Coorong channel, some of them 2 km or more from the shore. 


On Sunday our team was directed to try and catch, band and flag Banded Stilt chicks.  This exacting task required catching the chicks in hand nets in water that was shallow enough for us to run faster than the chicks could swim!  On land they could run faster than us but their instinct was to take to the water and swim out to deep water, which gave us a limited ÔwindowÕ of opportunity.  Once caught the 25 chicks were put into cloth bags, 3 chicks to a bag, to ÔhouseÕ them safely until a numbered metal band could be placed around the left ankle and orange and yellow plastic flags placed around the right thigh.  These did not impede the swimming, running or flying abilities of the chicks, but the flags could be easily spotted and the colors indicated that the bird had been banded, and in which country in Asia, or state in Australia this had been done.  Once completed the chicks were released in 3 groups in shallow water.  They immediately ran at speed in a tight group through the shallow water to join the main flock 500m or so up the beach.  25 fluffy chicks returned to the flock running lustily in comic style, bringing the total number of chicks banded this breeding cycle to 200 so far!


We carried out this banding on Aboriginal land on the Hack Peninsula and then had lunch in their Wilderness Centre Restaurant.  A memorable plateful of Coorong Mullet, Mulloway and kangaroo patties served with pasta and salad and accompanied by damper buns and slices of lemon was provided.  I can recommend it!  


Rob Tanner (08)8339-2835