LAUSR

Improved knowledge of dispersal parameters across multiple populations is essential for the effective management of species exposed to ongoing threats from habitat loss, fragmentation and climate change. Currently, management decisions are based on incomplete or insufficient knowledge of key dispersal parameters, especially long-distance dispersal, and its role in maintaining metapopulation connectivity, facilitating range shifts under climate change, or enabling the colonization of new habitats. Using a combination of microsatellite-based population genetic analyses, scaling relationships and parentage-based dispersal analysis we investigated levels and patterns of long-distance dispersal in the koala. Using home range size as a scalar predicted spatial variation in maximum dispersal distance amongst regional populations (range 13.4–43.4 km), while parentage-based dispersal analysis showed that long-distance dispersal (> 11.2 km) accounted for 16.7–18.5% of movements in a focal population. Common movement patterns were discerned, despite varying levels of imprecision and bias, that suggest an important role for long-distance dispersal in maintaining metapopulation connectivity. Our results suggest that implementation of a systematic approach to the estimation of dispersal across multiple populations would benefit koala conservation and management. This will require the use of both empirical and simulation studies to quantify and minimize sources of imprecision and bias that can occur including those related to incomplete sampling, the presence of fine-scale spatial genetic structure and areas of localized inbreeding. As limitations associated with partial sampling are likely to remain an inherent feature of large-scale dispersal studies, a large number of loci should be assayed.