Neotaphonomic study of two Tyto alba assemblages from Botswana: Palaeoecological implications

Abstract

By producing pellets rich in micromammal remains, owls are important contributors to small vertebrate accumulations in archaeological sites. Neotaphonomic studies are necessary to evaluate predation and fossilization biases before using pellet-derived assemblages to assess palaeoenvironmental reconstructions and micromammal community changes in plio-quaternary deposits. In this study, barn owl (Tyto alba) pellets were collected from two localities of Botswana with markedly different environments: the northern Kalahari (arid) and the Okavango Delta (humid). The taxonomic and taphonomic analyses of the two samples were compared with data from the literature on other T. alba pellet assemblages from Sub-Saharan Africa. This study provides additional data for the wildlife inventory at a local scale and further information about the diet and hunting habits of Tyto alba in this area, as well as its taphonomic impact on local rodent species. It confirms that barn owl assemblages are reliably good indicators of local environmental conditions. An application of palaeoecological methods was also made in order to evaluate the accuracy and performance of palaeoenvironmental reconstructions based on micromammal assemblages produced by owls in an archaeological context. Here, we discuss some methodological issues facing micromammal studies in southern Africa.