The Spectacled Flying-fox, Pteropus conspicillatus (Chiroptera: Pteropodidae), in north Queensland. I. Roost sites and di stribution panerns.

Abstract

Multiple regression analyses elucidated that the proximity of Pteropus conspicillatus roost sites to tracts of rainforest was the major factor determining distribution patterns. Colonies were found no further than 6.5 km from this resource in areas where annual rainfall was 1400 mm or greater. Colonies of the Black Flying-fox (P. alecto) located within the distribution of P. conspicillatus were in areas with similar or lower annual rainfall and averaged 61.2 km from rainforest. Six vegetation types were used as traditional roosts by P. conspicillatus, but of the 55 sites located, rainforest tracts or riverine rainforest were used significantly more than mangroves, paperbark swamps, tall eucalypt forest or Acacia spp. trees. Many colonies roosted throughout the year at coastal sites, but some colonies moved to upland areas. Movemem panerns may reflect the later ripening in upland areas of rainforest fruits distributed across both areas. Rainforest types in each area are different, and movements may also occur as colonies seek a different range of fruits. Mixing of P. conspicillatus in other colonies of Pteropus spp. was rare (5/166 observations), but was difficult to measure. Association with P. alecto occurred only when P. conspicillatus was in very low numbers at the P. alecto roost. Pteropus conspicillatus were never seen in P. scapulatus colonies, in fact, P. conspicillatus appeared to deliberately avoid this species. Some responses of P. conspicillatus to a severe tropical cyclone were to feed on clear ground for fallen fruit, and for colonies to fragment into small groups and roost in sites not previously occupied.