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Lapidge S.J.,University of Sydney | Lapidge S.J.,Invasive Animals Cooperative Research Center | Munn A.J.,University of Wollongong
Australian Journal of Zoology | Year: 2011

Captive breeding and release is a tool used by conservation biologists to re-establish populations of endangered or locally extinct species. Reintroduced animals that have been bred in captivity must learn to meet the challenges posed by free living, and to adjust to local environmental conditions, food and water sources. How well reintroduced animals might meet these challenges is uncertain as few longitudinal studies have investigated the physiology of reintroduced animals or the implications of this for successful establishment of new populations. Here we have evaluated long-term, seasonal energy and water use by reintroduced yellow-footed rock-wallabies (Petrogale xanthopus celeris), an endangered medium-sized marsupial that inhabits rocky outcrops across Australia's arid and semiarid rangelands. Captive-bred rock-wallabies were reintroduced to an area within the known boundaries of their former range, in south-western Queensland, Australia. Post-release water turnover rates (WTR) and field metabolic rates (FMR) were measured during their first wet summer and dry winter, by means of the doubly labelled water method. Total body water (73.1%), FMR (1650.0kJday-1), female fecundity (100%), and male and female body masses and survival were consistent between seasons, but rates of water turnover were significantly lower for all animals during the dry winter (174.3mLday-1) than during the wet summer (615.0mLday-1). There were no significant differences in WTR or FMR between males and lactating females (in either season). © CSIRO 2011.

Bengsen A.J.,University of Queensland | Leung L.K.-P.,University of Queensland | Lapidge S.J.,Invasive Animals Cooperative Research Center | Gordon I.J.,CSIRO | Gordon I.J.,James Hutton Institute
Journal of Wildlife Management | Year: 2011

The lack of variance estimates constrain the utility of abundance indices calculated from camera-trap data. We adapted a General Index model, which allows variance estimation, to analyze camera-trap observations of feral pigs (Sus scrofa) for population monitoring in a tropical rainforest. We tested whether the index would respond to population manipulation, and found that it decreased by 57% following removal of 24 pigs and remained low in the following period. Our method is useful for monitoring other large animals in difficult landscapes, and the model can be used to enhance the value of existing data sets. © 2011 The Wildlife Society.

Nystrom K.,University of Nantes | Le Gall-Recule G.,Laboratoire Of Ploufragan Plouzane | Grassi P.,Imperial College London | Abrantes J.,University of Nantes | And 8 more authors.
PLoS Pathogens | Year: 2011

Rabbit Hemorrhagic disease virus (RHDV), a calicivirus of the Lagovirus genus, and responsible for rabbit hemorrhagic disease (RHD), kills rabbits between 48 to 72 hours post infection with mortality rates as high as 50-90%. Caliciviruses, including noroviruses and RHDV, have been shown to bind histo-blood group antigens (HBGA) and human non-secretor individuals lacking ABH antigens in epithelia have been found to be resistant to norovirus infection. RHDV virus-like particles have previously been shown to bind the H type 2 and A antigens. In this study we present a comprehensive assessment of the strain-specific binding patterns of different RHDV isolates to HBGAs. We characterized the HBGA expression in the duodenum of wild and domestic rabbits by mass spectrometry and relative quantification of A, B and H type 2 expression. A detailed binding analysis of a range of RHDV strains, to synthetic sugars and human red blood cells, as well as to rabbit duodenum, a likely gastrointestinal site for viral entrance was performed. Enzymatic cleavage of HBGA epitopes confirmed binding specificity. Binding was observed to blood group B, A and H type 2 epitopes in a strain-dependent manner with slight differences in specificity for A, B or H epitopes allowing RHDV strains to preferentially recognize different subgroups of animals. Strains related to the earliest described RHDV outbreak were not able to bind A, whereas all other genotypes have acquired A binding. In an experimental infection study, rabbits lacking the correct HBGA ligands were resistant to lethal RHDV infection at low challenge doses. Similarly, survivors of outbreaks in wild populations showed increased frequency of weak binding phenotypes, indicating selection for host resistance depending on the strain circulating in the population. HBGAs thus act as attachment factors facilitating infection, while their polymorphism of expression could contribute to generate genetic resistance to RHDV at the population level. © 2011 Nyström et al.

Rovero F.,Sezione di Biodiversita Tropicale | Rovero F.,Udzungwa Ecological Monitoring Center | Zimmermann F.,KORA | Berzi D.,Canis lupus Italia | And 2 more authors.
Hystrix | Year: 2013

Automatically triggered cameras taking photographs or videos of passing animals (camera traps) have emerged over the last decade as one of the most powerful tool for wildlife research. In parallel, a wealth of camera trap systems and models has become commercially available, a phenomenon mainly driven by the increased use of camera traps by sport hunters. This has raised the need for developing criteria to choose the suitable camera trap model in relation to a range of factors, primarily the study aim, but also target species, habitat, trapping site, climate and any other aspect that affects camera performance. There is also fragmented information on the fundamentals of sampling designs that deploy camera trapping, such as number of sampling sites, spatial arrangement and sampling duration. In this review, we describe the relevant technological features of camera traps and propose a set of the key ones to be evaluated when choosing camera models. These features are camera specifications such as trigger speed, sensor sensitivity, detection zone, flash type and flash intensity, power autonomy, and related specifications. We then outline sampling design and camera features for the implementation of major camera trapping applications, specifically: (1) faunal inventories, (2) occupancy studies, (3) density estimation through Capture-Mark-Recapture and (4) density estimation through the Random Encounter Model. We also review a range of currently available models and stress the need for standardized testing of camera models that should be frequently updated and widely distributed. Finally we summarize the "ultimate camera trap", as desired by wildlife biologists, and the current technological limitations of camera traps in relation to their potential for a number of emerging applications. © 2013 Associazione Teriologica Italiana.

Sutherland D.R.,Invasive Animals Cooperative Research Center
Herpetologica | Year: 2011

Dietary separation is an important means of differentiating ecological niches and avoiding interspecific competition between sympatric species. Congeneric species that overlap in geographic distribution provide an excellent opportunity to explore the mechanisms of coexistence. Two monitor lizards, Varanus gouldii and V. rosenbergi (Varanidae), are sympatric at a local scale in the northern Jarrah Forest of Western Australia. Both species are wide-ranging terrestrial predators of a similar size and may differentiate their ecological niche by utilizing alternative foraging strategies resulting in dietary separation. Because varanid lizards are an important group of terrestrial high-order predators in the Old World, any such separation may have important implications for faunal community structure. In total, 169 scat and stomach samples were analyzed revealing extensive dietary overlap between the species. Dietary intake was not distinguishable between species or related to individual body size. Invertebrates were most important in terms of frequency and volume, although reptiles, mammals and birds were also commonly identified. Dietary partitioning is not the mechanism allowing these congeneric varanid lizards to coexist. © 2011 The Herpetologists' League, Inc.

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