Grey-headed flying fox  (Pteropus poliocephalus)

Although once thought to number in their millions, in 2002 there were estimated to be around 400,000 grey-headed flying foxes remaining (20). The most significant threat facing the bat is the destruction of foraging and roosting habitat due to expanding urbanisation and agriculture (7) (15). Climate change may also pose a threat to the grey-headed flying-fox as climate models are predicting significant increases in the occurrence of temperature extremes and recent research has shown that since 1994, more than 24,500 grey-headed flying foxes have died in their roosts when temperatures exceeded 42 degrees Celsius (21). Another serious threat is direct killing of animals in orchards and destruction of roosts. Many farmers perceive the bats to be pests due to the destruction they cause to crops and often kill them (22). Further more, negative public perception and consequent persecution of the species has intensified in the last decade with the discovery that it carries three new diseases that are potentially fatal to humans, Hendravirus, Menanglevirus and Australian Bat Lyssavirus (23) (24) (25). The exact numbers of bats killed is unknown, but estimates have been made as high as 100,000 annually, with the death of pregnant or lactating females obviously having an additional knock-on impact on the survival of their young (26). There is also a tendency for these bats to fly into power lines and die from electrocution. Black flying foxes (Pteropus alecto) pose a further threat through competition for food and habitat, and hybridisation between the grey-headed flying fox and the black flying fox has been observed (7) (27) (28).

In response to these growing threats, roost sites have been legally protected since 1986 in New South Wales and 1994 in Queensland (22). The grey-headed flying fox was also listed as vulnerable under the Environment Protection and Biodiversity Conservation Act in 1999, and the New South Wales Threatened Species Conservation Act Schedule 2 in 1995, which required that a Recovery Plan be prepared by 2006 (27) (29) (30). Conservation reserves are limited, and future efforts to protect more key foraging areas would be extremely beneficial, by helping to ensure that food supplies are available throughout the year (2). Research into alternative, non-lethal crop protection mechanisms, and encouragement of horticulturists to use them, is also crucial in the fight to protect this species (2). As important pollinators and seed dispersal agents, these bats are integral in maintaining healthy forest ecosystems (16). Thus, unless swift action is taken to halt further population reductions, the decline of the grey-headed flying fox is likely to have a serious negative, long-term impact on the regeneration of Australia’s forests, and the host of unique fauna they harbour.