Flying-foxes are large bats that feed on nectar, pollen and fruit at night, and roost by day in colonies in the thousands. They are amongst the most mobile mammals on Earth and can track changes in floral resources across much of Australia’s north and east, where they are pivotal for pollination and seed dispersal in forests. Populations have experienced declines since European colonisation due to habitat destruction and persecution, and the Grey-headed and the Spectacled flying-fox are listed as threatened nationally.
Flying-fox roosts are now increasingly urban, potentially because of the feeding opportunities these areas provide and loss of habitat elsewhere. This causes community concern because roosting flying-foxes are noisy, smelly, can damage vegetation and property, and are often perceived as carriers of diseases. Concern is exacerbated when local mass flowering leads to the sudden (and often short-term) arrival of thousands of flying-foxes. This is usually interpreted to mean that there has been an overall population increase, causing some to question the species’ protected status and to call for ‘dispersal’ involving the use of disturbances to encourage the bats to move elsewhere. Urban dispersals require sustained effort over long periods, can cost millions of dollars, and typically either fail to move the bats along or force them into even more contentious areas.
There is an urgent need to experimentally test the efficacy of alternative mitigation measures, and to cater local management to the social context of each roost. Approaches currently being trialled include the installation of double-glazing and shade cloth to buffer noise and smell, vegetation pruning and revegetation to increase the distance between roosts and people’s amenity, and education programs to change perceptions. These have the potential to deliver longer-term socially acceptable outcomes.