Fast food in the city? Nomadic flying-foxes commute less and hang around for longer in urban areas

Urbanization creates novel ecological spaces where some species thrive.
Geographical urbanization promotes human-wildlife conflict; however, we
know relatively little about the drivers of biological urbanization, which
poses impediments for sound wildlife management and conservation action.
Flying-foxes are extremely mobile and move nomadically in response to
flowering resources, but are now increasingly found in urban areas, for
reasons that are poorly understood. To investigate the mechanisms behind
flying-fox urbanization, we examined the movement of 99 satellite tracked
grey-headed flying-foxes (Pteropus poliocephalus) over one year in urban
versus non-urban environments. We found that tracked individuals
preferentially visited major-urban roosts, exhibited higher fidelity to
major-urban roosts, and foraged over shorter distances when roosting in
major-urban areas. In contrast to other colonial species, there were no
density-dependent effects of colony size on foraging distance, suggesting
that at a landscape scale, flying-foxes distribute themselves across
roosts in an ideal-free manner, minimising competition over urban and
non-urban foraging resources. Yet, males consistently foraged over shorter
distances than females, suggesting that at a local scale foraging
distances reflect competitive inequalities between individuals. Overall,
our study supports the hypothesis that flying-fox urbanization is driven
by increased spatiotemporal availability of food resources in urban areas;
however, unlike in other species, it is likely a consequence of increased
urban visitation by nomadic individuals rather than a subset of the
population becoming ‘urban residents’ per se. We discuss the implications
of the movement behavior we report for the conservation and management of
highly mobile species.