DOI: 10.5061/dryad.mcvdncjz2
title: Extreme mobility of the world’s largest flying mammals creates key challenges for management and conservation

description: Background: Effective conservation management of highly mobile species
 depends upon detailed knowledge of movements of individuals across their
 range; yet, data are rarely available at appropriate spatiotemporal
 scales. Flying-foxes (Pteropus spp.), are large bats that forage by night
 on floral resources and rest by day in arboreal roosts that may contain
 colonies of many thousands of individuals. They are the largest mammals
 capable of powered flight, and they are highly mobile, which makes them
 key seed and pollen dispersers in forest ecosystems. However, their
 mobility also facilitates transmission of zoonotic diseases and brings
 them in conflict with humans, and so require a precarious balancing of
 conservation and management concerns throughout their Old World range.
 Here we analyse the Australia-wide movements of 201 satellite-tracked
 individuals, providing unprecedented detail on the inter-roost movements
 of three flying-fox species: Pteropus alecto, P. poliocephalus, and P.
 scapulatus across jurisdictions over up to five years. Results:
 Individuals were estimated to travel long distances among a network of 755
 roosts, with P. alecto reaching more than 1,800 kilometers a year, P.
 poliocephalus up to 2,500 kilometers a year and P. scapulatus up to 6,000
 kilometers a year, but with little uniformity among their directions of
 travel. This indicates that flying-fox populations are composed of
 extremely mobile individuals that move nomadically and at species-specific
 rates. Individuals of all three species exhibited very low fidelity to
 roosts, resulting in very high estimated colony turnover rates. This
 indicates that flying-fox roosts form nodes in a vast continental network
 of ‘staging posts’ through which highly mobile individuals travel far and
 wide across their species range.  Conclusions: The extreme
 inter-roost mobility reported here demonstrates the extent of the
 ecological linkages that nomadic flying-foxes provide across Australia’s
 contemporary fragmented landscape, with profound implications for the
 ecosystem services and zoonotic dynamics of flying-fox populations. In
 addition, the extreme mobility of the species means that impacts from
 local management actions can readily reverberate across jurisdictions
 throughout the species ranges; therefore, local management actions need to
 be assessed with reference to actions elsewhere and hence require national
 coordination. These findings underscore the need for sound understanding
 of animal movement dynamics to support evidence-based, transboundary
 conservation and management policy, tailored to the unique movement
 ecologies of species.  
description: ARGOS PTTs were fitted to 99 flying-foxes, n=49 males, 50
 females.We managed data from deployed PTTs in a standardized format in
 Movebank (http://www.movebank.org/node/2). Prior to analysis, we examined
 the datasets for inconsistencies, and fixes with ARGOS code Z, along with
 fixes with longitudes &gt;140 or latitudes &lt;0, were removed. We
 used daytime fixes (between 10 am and 4 pm) to assign animals to a “roost
 site” (as mainland Australian flying-foxes do not forage during the day).
 If high resolution (ARGOS location code 3) daytime fixes occurred within
 3.5 km of a “known colony”, we assumed animals were roosting at that site.
 Where accurate daytime fixes were more than 3.5 km from a known roost
 location, we manually assigned animals to a new “roost site” located at
 the center of the cluster of fixes. If multiple tracked individuals
 roosted at the same location, this new roost site was confidently
 considered to be a previously unidentified ‘colony’ of
 flying-foxes.  Data consists of 3 csv files of monthly
 directional movements, movements and distance between roost sites and
 seasonal directed movement.