Gibson Desert birds: responses to drought and plenty

There is little information on the response of birds to rainfall in the Australian arid zone. Counts of birds between 1988 and 1992 on paired 1-km(2) quadrats representing major landform and vegetation types in the Gibson Desert revealed significant changes in species richness, community composition and abundance during increasing drought and following drought- breaking high rainfall. Species considered sedentary or resident ( sedentary - resident), which were insectivorous or carnivorous, declined in abundance as the drought progressed, with at least one species, Rufous- crowned Emu- wren ( Stipiturus ruficeps), apparently disappearing from the quadrats and not reappearing following heavy rainfall. Irruptive species, which were granivorous, nectarivorous or insectivorous, included species first recorded after heavy rainfall. Some species often considered to be nomadic, such as White- fronted ( Phylidonyris albifrons) and Pied ( Certhionyx variegatus) Honeyeaters, appeared to be both sedentary - resident and irruptive. Most species were recorded in more than one quadrat- pair; a few were recorded only in Mulga ( Acacia aneura) tall shrubland - Common Bronzewing ( Phaps chalcoptera), Boobook Owl ( Ninox novaeseelandiae), Spotted Nightjar ( Eurostopodus argus), Ground Cuckoo- Shrike ( Coracina maxima) and Inland Thornbill ( Acanthiza apicalis). Breeding activity showed a strong correlation with rainfall, with more breeding occurring in spring than the previous autumn.