The establishment and dynamics of a recently established urban camp of flying foxes (Pteropus poliocephalus) outside their geographic range


R. van der Ree, Australian Research Centre for Urban Ecology, Royal Botanic Gardens Melbourne, C/- School of Botany, University of Melbourne, 3010, Victoria, Australia


Grey-headed flying foxes Pteropus poliocephalus (Megachiroptera: Pteropodidae), listed nationally in Australia as vulnerable, have been recorded infrequently in low numbers in Melbourne from the first record of the species in 1884 till the early 1980s. The number of individuals and duration of their visit to Melbourne increased dramatically in the early 1980s, with the first year-round presence occurring in 1986 within the Royal Botanic Gardens, Melbourne. Anecdotal information suggests that the Melbourne colony has been continuously present since 1986; however, counts of roosting animals were sporadic between 1987 and 1993. Regular monthly counts that began in December 1993 confirm the continuous presence of the species in Melbourne from that date onwards. The growth of the size of the colony from 1994 onwards was exponential, with a peak in March 2003 (when counting ceased) at between 20 000 (static count) and 30 000 (flyout count) individuals. The number of P. poliocephalus within the colony fluctuated across the year, with a peak in summer/autumn (December–May) and a trough in winter/spring (July–October). The exact timing of the influx of animals varied slightly from year to year. The establishment of the permanent camp in urban Melbourne is a range expansion for the species.