Little is known about the effects of temperature extremes on natural systems. This is of increasing concern now that climate models predict dramatic increases in the intensity, duration and frequency of such extremes. Here we examine the effects of temperature extremes on behaviour and demography of vulnerable wild flying-foxes (Pteropus spp.). On 12 January 2002 in New South Wales, Australia, temperatures exceeding 428C killed over 3500 individuals in nine mixed-species colonies. In one colony, we recorded a predictable sequence of thermoregulatory behaviours (wing-fanning, shade-seeking, panting and saliva-spreading, respectively) and witnessed how 5-6% of bats died from hyperthermia. Mortality was greater among the tropical black flying-fox, Pteropus alecto (10-13%) than the temperate grey-headed flying-fox, Pteropus poliocephalus (less than 1%), and young and adult females were more affected than adult males (young, 23-49%; females, 10-15%; males, less than 3%). Since 1994, over 30 000 flying-foxes (including at least 24 500 P. poliocephalus) were killed during 19 similar events. Although P. alecto was relatively less affected, it is currently expanding its range into the more variable temperature envelope of P. poliocephalus, which increases the likelihood of die-offs occurring in this species. Temperature extremes are important additional threats to Australian flying-foxes and the ecosystem services they provide, and we recommend close monitoring of colonies where temperatures exceeding 42.08C are predicted. The effects of temperature extremes on flying-foxes highlight the complex implications of climate change for behaviour, demography and species survival.

The foraging movements of 13 Pteropus alecto from four camps in suburban Brisbane were monitored over two summer and one winter season between 1998 and 2000. By means of radio-telemetry, the flying-foxes were tracked to their foraging sites over 49 nights for a total of 237 h. Data from flying-foxes tracked from dusk to dawn showed that bats travelled directly to a foraging site early in the night and undertook smaller movements between foraging sites for the remainder of the night. Bats undertook a greater number of nocturnal movements during a food resource shortage than during a season of greater resource abundance. Mean distances (±s.e.) travelled from camps to foraging sites varied between camps and ranged from 2.9 ± 0.3 km (n = 24) to 7.6 ± 0.07 km (n = 2). In all three seasons, flying-foxes foraged on a variety of native and exotic plant species. Dominant exotics included Cocos palms (Sygarus romanzoffiana), Chinese elm trees (Celtis sinensis) and Cadaghi (Corymbia torrelliana), while highly utilised native food plants included figs (Ficus spp.), grevilleas (Grevillea spp.) and bottlebrushes (Callistemon spp.).

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ABSTRACT. The aim of the study was to monitor the social development of infant and juvenile common chimpanzees (Pan troglodytes) through their play behaviour at Taronga Zoo in Sydney in order to examine the possible effects of captivity (such as limited opportunities to play) on social development. Play behaviour was observed by focal animal sampling to determine individual differences, and their relationship to age, sex, and relatedness of the subjects. Analysis revealed marked individual variations in social, solitary, and object play behaviours indicative of a relatively wellbalanced social and physical environment. Subjects showed a marked preference for play-partners of a different age compared to their own, and initiated interactions with similar frequency with members of both sexes. Many social-play dyads consisted of related individuals, and familiarity with prospective play-mates was the most decisive factor in social interactions.