Behaviour 2019
The private life of the Greater Bilby: exploring bilby sociality in a semi-wild sanctuary 
Kate A. Cornelsen1, Neil R. Jordan1,2, Andrew Elphinstone2. 1Centre for Ecosystem Science, University of New South Wales, Sydney, NSW, Australia; 2Taronga Institute of Science of Learning, Taronga Conservation Society Australia, Mosman, NSW, Australia

Species reintroductions aim to reinstate species within their former range. The genetic diversity of re-introduced populations can be boosted by introducing more, genetically diverse animals to a population. However, if new animals do not reproduce, due to competition with established animals, this strategy may not be effective. Greater Bilbies (Macrotis lagotis) were released in stages to a semi-wild sanctuary where bilby sociality and breeding was examined to (i) test social strength between individuals and release groups, and (ii) determine if association between male-female pairs could be linked to early breeding success. Bilby movements were tracked post-release. Burrow sharing and nightly proximity was used to define sociality. Bilbies shared burrows on 44% of observations, with most observations between mixed sex groups (76% of sharing observations). Burrow sharing may be important for bilby breeding, and our data suggests that established males likely out-compete new males for these breeding opportunities. Early parentage results indicate that social position, and association strength between male-female pairs may be important for bilby breeding success.