Foraging behaviour of mulga birds in Western Australia. I. Use of resources and temporal effects

Abstract

The foraging behaviour of mulga birds in the Murchison and Gascoyne Bioregions was studied in 1999 following a period of heavy rain and again in 2002 when it was dry. Mulga birds allocated foraging resources in a similar fashion to other bird communities, with species differing in the way that prey were taken, the substrates and plant species on which prey were found, and the heights at which prey were sought. The numbers of birds and bird species in the study areas declined with drier conditions and there was less breeding activity. Nomadic species, including honeyeaters, seed-eaters, and insect-eaters, largely left the area as it became drier and food resources changed. The birds that remained foraged differently when it was drier than when conditions were wetter and food more abundant. These observations illustrate the fragility of the mulga avifauna and its likely sensitivity to long-term climate change with predicted increasing temperatures, more extreme heat events, and reduced winter rainfall. Conservation of mulga birds and associated flora and fauna requires a whole-of-landscape approach and the adoption of land management practices by Australian governments and land managers that will allow species to adapt to climate change and guarantee their right to evolve.