Assessing the affiliative behaviors of captive ghost bats (Macroderma gigas) at Perth Zoo, Western Australia
Australia: Rainforest, Reef, and Cultural Ecology
The ghost bat (Macroderma gigas) is the largest microchiropteran and only carnivorous bat species endemic to Australia. Since European settlement, habitat loss from activities such as mining have limited the ghost bat’s preferred roosting sites, causing the species to contract its range northward. Through captive breeding programs, Perth Zoo has successfully maintained a colony of ghost bats since 1977 with recent intent for re-introduction to the wild in the future. Perth Zoo wanted to monitor the affiliative behaviors of M. gigas prior to the upcoming breeding season and assess any aggressive interactions between the bats. The current study found that both male and female bats exhibit a majority of time hanging, with the females in proximity to each other more than the males. Although rarely observed, the males exhibited more negative affiliative behavior than the females. The males exhibited territorial establishment whereas the females exhibited a more consistent spatial use of their enclosure. Both sexes preferred roosting sites with mock rock or wire substrates, in the upper level of the enclosure and in close proximity to heat lamps or cave entrances. During day-light, both sexes showed positive affiliative behavior towards the “colony” however, this behavior was decreased in hours of darkness. No negative affiliative behavior was observed for both sexes while feeding, suggesting that there was no resource competition for food. Findings of the current study suggest that the overall welfare of M. gigas is good prior to the breeding season. The current study provides baseline data to compare bat behavior throughout the coming seasons. Ghost bats are endemic to Australia, and with populations at risk in the wild it is important that Perth Zoo continues to monitor and maintain its captive breeding programs for possible re-introduction of this species in the future.