Fossil bird assemblages from Australian caves: precise indicators of late Quaternary environments?

Abstract

Fossil bird assemblages in Australia are regarded as more indicators of late Quaternary environments than microfloral and micromammalian assemblages because of the low level of identification of the target taxa (e.g. to genus and species levels), the accuracy to which one can define the target taxon's niche, the presence of avian assemblages throughout the late Quaternary of Australia and the determination of the taphonomy of deposits within which avian assemblages are known. The predator most frequently defined as having accumulated these deposits is the barn owl ( Tyto alba). The foraging range of this species has been used to define the area surrounding the deposit within which the palaeoenvironmental reconstruction is pertinent. The precision of the reconstructions is largely controlled by sedimentological and diagenetic factors that effect the chronostratigraphic distribution of avian material. Reconstruction of the palaeoenvironment of southern Australia, based upon avian material, indicates a lowering of effective precipitation around 30,000 years ago. This drier regime lasted between 30,000 and 10,000 yr B.P. after which the precipitation increased to present-day levels.