Activity budgets of waterfowl (Anatidae) on a waste-stabilisation pond

Abstract

This study investigated the activity budgets of eight species of waterfowl on a waste-stabilisation pond known to support a large waterfowl community. Most species examined were found to use the area extensively for feeding. Pink-eared Duck (Malacorhynchus membranaceus), Australasian Shoveler (Anas rhynchotis), Grey Teal (A. gibberifrons) and Chestnut Teal (A. castanea) fed most intensively at sunrise and sunset, and rested during the middle of the day. Hardhead (Aythya australis), a diving species, Australian Shelduck (Tadorna tadornoides) and Pacific Black Duck (Anas superciliosa) - large birds that were presumably able to reach the benthos from the water's surface - fed at relatively consistent levels throughout the day. Black Swans (Cygnus atratus) steadily increased the amount of time spent feeding from dawn to dusk. The diurnal activity budgets of these Australian species were similar to those observed for other species occupying similar ecological niches elsewhere. Imminent changes to sewage treatment operations may reduce the ability of this waste-stabilisation pond to support waterfowl populations. The monitoring of activity budgets after any such changes are implemented should be an effective means of detecting any effects, negative or positive.

This study investigated the activity budgets of eight species of waterfowl on a waste-stabilisation pond known to support a large waterfowl community. Most species examined were found to use the area extensively for feeding. Pink-eared Duck (Malacorhynchus membranaceus), Australasian Shoveler (Anas rhynchotis), Grey Teal (A. gibberifrons) and Chestnut Teal (A. castanea) fed most intensively at sunrise and sunset, and rested during the middle of the day. Hardhead (Aythya australis), a diving species, Australian Shelduck (Tadorna tadornoides) and Pacific Black Duck (Anas superciliosa) - large birds that were presumably able to reach the benthos from the water's surface - fed at relatively consistent levels throughout the day. Black Swans (Cygnus atratus) steadily increased the amount of time spent feeding from dawn to dusk. The diurnal activity budgets of these Australian species were similar to those observed for other species occupying similar ecological niches elsewhere. Imminent changes to sewage treatment operations may reduce the ability of this waste-stabilisation pond to support waterfowl populations. The monitoring of activity budgets after any such changes are implemented should be an effective means of detecting any effects, negative or positive.