Dry season camps of flying‐foxes (Pteropus spp.) in Kakadu World Heritage Area, north Australia

Abstract

We investigated camps of black Pteropus alecto and red¯ying-fox P. scapulatus in the early dry season of 1992 (April±June) in Kakadu National Park, a World Heritage Area in the wet-dry tropics of north Australia. Fifteen camp-sites were located and two types of camps were de®ned: main camps containing > 1000 animals and a signi®cant component of young (P. alecto, n = 4; P. scapulatus, n = 2) and satellite camps of lesser size (P. alecto, n = 9; P. scapulatus, n = 3). The two species shared three camp-sites. All camps were in dense riparian vegetation (fresh and saltwater mangroves, paperbark forests, closed forest and bamboo), overhanging or adjacent to water inhabited by crocodiles, that would provide a protected microclimate and protection from predators. All camps were within 5 km or less of one or more unoccupied sites that were indistinguishable in landform or vegetation from camp-sites. In Kakadu NP riparian vegetation makes up about 6% of the park and is a non-limiting resource for¯ying-fox roosting. We propose that the initial colonization of camp-sites is essentially random when roost vegetation is nonlimiting and that factors such as predation by humans, cyclones and ®res determine the persistence and size of camps at the local level. At a broader temporal and spatial scale, interaction between the seasonal availability of forage and reproductive cycles is known to in¯uence the location, size and structure of Pteropus camps. We advance the hypothesis that colonies of¯ying-foxes could be moved to new campsites, a strategy that would facilitate resolution of the frequently problematic management of these animals.

Climate Change Could Increase the Geographic Extent of Hendra Virus Spillover Risk

“…Sources of uncertainty may be related to: (1) the type of presence only data used limits the number of analytical methods that can be used and hampers the identification of limiting factors; (2) the effects of climate on HeV spillover act at several different levels of ecological organisation and are not well understood, for instance temperature, humidity and ground vegetation might also limit the available pathways for HeV transmission to horses (Martin et al 2017), and temperature can regulate the flowering status of native plants (Hudson et al 2010), the main source of food for flying foxes; (3) flying fox species distributions do not depend entirely on climate (Tidemann et al 1999; Vardon et al 2001), but are greatly affected by native plant phenology (Giles et al 2016), and have an apparently innate preference for fragmented and urbanised landscapes (Tait et al 2014); (4) the predicted distributions of flying foxes in response to climate change do not account for other organisms’ shifting distributions that affect bats’ distributions. Other organisms shifting distributions might give rise to novel and unpredictable interactions and effects on bats’ distributions (Eby et al 1999; Eby and Law 2008; Giles et al 2016); and (5) climate change could also affect horse behaviour and susceptibility to diseases.…”

Seasonal habitat use by flying‐foxes, Pteropus alecto and P. scapulatus (Megachiroptera), in monsoonal Australia

“…In such circumstances the observed pattern of habitat use may be predominantly artefactual, being dictated largely by the availability of remnant vegetation. Most species in these conditions are declining, suggesting that environmental conditions are far from optimal (Mickleburgh et al, 1992;Tidemann et al, 1999). Northern Australia retains much of its natural vegetation (Whitehead, Bowman & Tidemann, 1992;Woinarski, Whitehead et al, 1992;Woinarski, Connors & Oliver, 1996) and the study of¯ying-foxes in this environment should avoid the inevitable biases of studies of species in disrupted habitats .…”

“…The black¯ying-fox Pteropus alecto and little red ying-fox P. scapulatus are common in northern Australia , 1998Tidemann et al, 1999). Pteropus alecto is one of the world's largest bats, with the maximum weight of males exceeding 1100 g (C. Tidemann & M. Vardon, pers.…”

Changing resource landscapes and spillover of henipaviruses

“…46,82 Similar patterns are being observed in numerous species elsewhere around the world, with additional studies from Australia, Thailand (Pteropus lylei), Fiji (Pteropus tonganus), India (Cynopterus sphinx), Pakistan (P. medius), Japan (Pteropus dasymallus inopinautus), and Malaysia (Pteropus vampyrus and Pteropus hypomelanus) suggesting that food resource limitation following habitat loss drives fruit bats to feed and roost in urban and agricultural landscapes. [42][43][44][45][46][47][89][90][91] Such changes in flying fox distribution in response to urban and agricultural habitats could change the spatial dynamics of HNVs and the risk of spillover. Urban habituation increases the overlap of bats and spillover recipient hosts of disease.…”