Avocet breeding habitat, behaviour, and nesting platform use Gyug and Weir 13 American Avocet breeding habitat, behaviour and use of nesting platforms at Kelowna, British Columbia Les W. Gyug1 and Jason T. Weir2 1 Okanagan Wildlife Consulting, 3130 Ensign Way, West Kelowna, BC V4T 1T9
[email protected] 2 Dept. of Biological Sciences and Dept. of Ecology and Evolution, University of Toronto, 1265 Military Trail, Toronto, ON M1C 1A4
[email protected] Abstract: The largest and most consistently used American Avocet (Recurvirostra americana) colony in British Columbia is located in the southern half of the former Alki Lake, Kelowna. This lake was a landfill active from the 1960’s to 1980’s, and is now slated to be filled in completely as the landfill reexpands into the remnants of the lake. Here, we report avocet behaviour, nest conditions and foraging habitat characteristics in 1999 at Alki Lake and five other wetlands in the Kelowna area to inform future mitigation strategies for this colony. Thirteen breeding pairs initiated 21 nests (including renesting after failed attempts) at Alki Lake in 1999, with no nests in other Kelowna area localities. Fifteen nests were on islands, five on 1.2 m square floating nest platforms, and one on a shoreline mudflat. Nesting on floating nest platforms had not been previously reported for American Avocets. Foraging areas regularly used by individual pairs were not necessarily adjacent to the nest, and increased from 0.32 ha during the incubation period to 0.53 ha after hatching. Avocets foraged primarily in soft silt substrates along nonvegetated shorelines and in shallow mudflats at a mean depth of 10 cm.