Vertebrate Pest Research Section

Forrestfield, Australia

Vertebrate Pest Research Section

Forrestfield, Australia
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Spencer P.B.S.,Murdoch University | Giustiniano D.,Murdoch University | Hampton J.O.,Murdoch University | Gee P.,Rural Solutions | And 4 more authors.
Journal of Wildlife Management | Year: 2012

The dromedary camel (Camelus dromedarius) is a significant invasive species in Australia. It is an unusual pest species that is of large body size with relatively low fecundity compared with other pest species. Camels are highly adapted to the arid regions that characterize a large proportion of Australia and occupy an almost completely undisturbed area of ≥3 million km 2. They have no history of invasion elsewhere in the world. Despite this, their population has been expanding at approximately 80,000 camels per annum, with the most recent estimate of population size around 1,000,000 individuals. We employed a landscape-genetic approach to evaluate the population structure and molecular ecology of Australian camels. We combined mitochondrial control region sequence (n = 209 animals) with 18 microsatellite markers to profile over 800 adult camels to identify the presence of a single panmictic population. We showed that demographically defined neighborhoods for wild camels are about 200 km; this value was supported by home range estimates. Distances greater than this display no pattern of isolation by distance across the Australian continent. The result is the largest single geographical population so far recorded for an invasive species in Australia. This pattern may be explained by the impressive and near-nomadic dispersal pattern of camels, in combination with an unpredictable environment virtually devoid of barriers to movement and predatory suppression. Although it is technically feasible, the reality is that it would not be economically or politically viable to have continental eradication of wild camels in Australia because of the vast size and movement dynamics of the camel population. As such, we advocate a change away from an expensive solution to an intractable reduction program (that is almost entirely focused on protection of biological refugia) and moves to include cultural, economic, and biodiversity asset protection for the management of this most unorthodox of invasive species. © 2012 The Wildlife Society.

Woolnough A.P.,Vertebrate Pest Research Section | Woolnough A.P.,Australian Department of Primary Industries and Fisheries | Hampton J.O.,Vertebrate Pest Research Section | Campbell S.,Vertebrate Pest Research Section | And 4 more authors.
Journal of Wildlife Diseases | Year: 2012

The Judas technique is a method used for landscape control of feral donkeys (Equus asinus) in northern Australia. Central to the success of any Judas program is the safe, efficient, and humane attachment of the telemetry device. For feral donkeys, this involves the use of field immobilization. We examine the replacement of the current chemical capture agent, succinylcholine, with contemporary immobilization agents to achieve positive animal welfare outcomes. A combination of medetomidine and ketamine delivered by remote injection from a helicopter was used to capture 14 free-ranging feral donkeys for the fitting of telemetry collars in Western Australia in November 2010. Dose rates of 0.14 mg/kg medetomidine and 4.1 mg/kg ketamine were appropriate to immobilize animals in 9 min (±SD53). Mean recovery time (total time in recumbency) was 21 min (±14). All animals recovered uneventfully after being administered atipamezole, a specific antagonist of medetomidine, intramuscularly at 0.35 mg/kg. Physiologic parameters were recorded during recumbency, with environment-related hyperthermia being the only abnormality recognized. No significant complications were encountered, and this drug combination represents an efficient approach to capturing wild donkeys. This new method allows a rapid, safe, cost-effective approach to the immobilization of feral donkeys for use as Judas animals. This drug combination will replace the relatively inhumane succinylcholine for the field immobilization of feral donkeys. © Wildlife Disease Association 2012.

Campbell S.,Vertebrate Pest Research Section | Cook S.,University of Ballarat | Mortimer L.,University of Ballarat | Palmer G.,University of Ballarat | And 3 more authors.
Wildlife Research | Year: 2012

Context Worldwide, invasive fauna species present one of the most intractable problems for agriculture and natural systems. Our ability to improve control techniques to combat the global invasive species predicament is constrained within the bounds of both economic and ethical considerations. In south-eastern Australia, the common starling (Sturnus vulgaris) is an established invasive avian pest that is now making incursions into areas of Western Australia (WA) that are currently free of this species. The most cost-effective and widely implemented starling control tool is trapping with live-lure birds. In recent years, the use of live-lure birds has been questioned on both economic and ethical grounds, and consequently alternative lure methods need investigating. Aims To evaluate the effectiveness of different trap and lure combinations for the capture of starlings in western South Australia (SA). Methods Modified Australian Crow (MAC) traps, used traditionally in WA to trap starlings, and Myna traps, originally designed for trapping common mynas (Sturnus tristis), were set during the peaks in starling flocking activity (Austral summer, 2007) using three different lure types: (1) live lure (live starlings); (2) moving water; and (3) acoustic lures. A trapping grid consisting of a single Myna trap with live lure and three MAC traps, each with one type of lure (live, water or acoustic) was established at five sites on the Eyre Peninsula in SA and monitored twice daily for 28 days. Key results Live lures were significantly more effective at attracting starlings into traps compared with both water and sound lures. We also trapped at an additional three sites and showed that Myna traps caught ∼1.5 times more starlings than MAC traps when both traps were fitted with live-lure birds. Conclusions Neither moving water nor acoustic play-back lures proved suitable replacements for the use of live-lure birds to capture starlings. The efficacy of alternative lure types may depend on several factors and may include neophobic response(s) to novel signals and also the length of time that an invasive population has been established. Implications We recommend that use of live lures is continued in ongoing starling control programs, and that MAC traps currently in use be modified to capitalise on known starling behaviour. Further research and development of traps that do not contain live lures will improve the welfare of invasive species control programs. © 2012 CSIRO.

Campbell S.,University of Melbourne | Campbell S.,Vertebrate Pest Research Section | Coulson G.,University of Melbourne | Lumsden L.F.,Arthur Rylah Institute for Environmental Research
Acta Chiropterologica | Year: 2010

The thermal environment of day roosts is considered one of the most influential factors affecting the survival, growth and reproduction of microbats. The use of torpor is a common energy saving strategy employed by microbats in temperate regions. The efficiency of entry into, and arousal from, torpor is governed by roost microclimate, primarily roost temperature. The large-footed myotis Myotis macropus roosts in both tree cavities and a man-made tunnel at Yan Yean reservoir in Victoria, Australia. We investigated the thermal properties of both roost types in comparison to available tree cavities and ambient temperature over four time periods from October 2003 to May 2005. Tree cavities and tunnel roosts remained significantly warmer at night, cooler during the day, and were more stable than ambient temperatures. In addition, roost tree cavities were significantly cooler between 10:0013:00 h compared to available tree cavities, and there was a trend for roost tree cavities to be slightly warmer at night and slower to reach maximum temperature relative to available tree cavities during the breeding season (OctoberJanuary). In contrast, there was little difference in roost and available tree cavity temperatures outside of the breeding season (AprilMay). Temperatures inside tunnel roosts were more stable and were significantly cooler during the afternoon compared to roost tree cavities during both the breeding and non-breeding seasons. Myotis macropus may actively trade-off the enhanced thermoregulatory benefits of warm roosts for reduced predation risk associated with the tunnel roosting environment. © Museum and Institute of Zoology PAS.

Rollins L.A.,University of New South Wales | Rollins L.A.,Deakin University | Whitehead M.R.,University of New South Wales | Whitehead M.R.,The Australian National University | And 5 more authors.
Current Zoology | Year: 2015

Although population genetic theory is largely based on the premise that loci under study are selectively neutral, it has been acknowledged that the study of DNA sequence data under the influence of selection can be useful. In some circumstances, these loci show increased population differentiation and gene diversity. Highly polymorphic loci may be especially useful when studying populations having low levels of diversity overall, such as is often the case with threatened or newly established invasive populations. Using common starlings Sturnus vulgaris sampled from invasive Australian populations, we investigated sequence data of the dopamine receptor D4 gene (DRD4), a locus suspected to be under selection for novelty-seeking behaviour in a range of taxa including humans and passerine birds. We hypothesised that such behaviour may be advantageous when species encounter novel environments, such as during invasion. In addition to analyses to detect the presence of selection, we also estimated population differentiation and gene diversity using DRD4 data and compared these estimates to those from microsatellite and mitochondrial DNA sequence data, using the same individuals. We found little evidence for selection on DRD4 in starlings. However, we did find elevated levels of within-population gene diversity when compared to microsatellites and mitochondrial DNA sequence, as well as a greater degree of population differentiation. We suggest that sequence data from putatively nonneutral loci are a useful addition to studies of invasive populations, where low genetic variability is expected. © 2015 Current Zoology.

Rollins L.A.,Deakin University | Rollins L.A.,University of New South Wales | Woolnough A.P.,Transport and Resources | Woolnough A.P.,Vertebrate Pest Research Section | And 9 more authors.
Molecular Biology and Evolution | Year: 2016

Mitochondria are critical for life, yet their underlying evolutionary biology is poorly understood. In particular, little is known about interaction between two levels of evolution: between individuals and within individuals (competition between cells, mitochondria or mitochondrial DNA molecules). Rapid evolution is suspected to occur frequently in mitochondrial DNA, whose maternal inheritance predisposes advantageous mutations to sweep rapidly though populations. Rapid evolution is also predicted in response to changed selection regimes after species invasion or removal of pathogens or competitors. Here, using empirical and simulated data from a model invasive bird species, we provide the first demonstration of rapid selection on the mitochondrial genome within individuals in the wild. Further, we show differences in mitochondrial DNA copy number associated with competing genetic variants, which may provide a mechanism for selection. We provide evidence for three rarely documented phenomena: selection associated with mitochondrial DNA abundance, selection on the mitochondrial control region, and contemporary selection during invasion. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved.

Spencer P.B.S.,Murdoch University | Woolnough A.P.,Vertebrate Pest Research Section
Livestock Science | Year: 2010

Camels are substantial providers of transport, milk, sport, meat, shelter, fuel, security and capital in many countries. In Australia there are estimated to be over a million individuals, and growing at more than 80,000 per year. Australian dromedary camels may therefore represent a considerable resource for the world's camel production herd. Here we document the structure and assess the genetic diversity over a very large sampling area (> 3 million km2). Using a total of 484 reproductive individuals belonging to six sampling locations of dromedary camel (Camelus dromedaries) we analysed 28 microsatellite markers to assess polymorphism in the Australian herd. Eighteen of these markers were polymorphic, producing a total of 185 alleles. Unlike camel breeds from elsewhere in the world, the classification of Australian camels into distinguishable breeds was not supported by the program STRUCTURE at the microsatellite level. Australian camels also showed very weak levels of sampling structure (and genetic diversity) suggesting a small historical founder size. © 2010 Elsevier B.V. All rights reserved.

Rollins L.A.,University of New South Wales | Woolnough A.P.,Vertebrate Pest Research Section | Sinclair R.,Khan Research Laboratories | Mooney N.J.,2 Torrens Road | Sherwin W.B.,University of New South Wales
Molecular Ecology | Year: 2011

Mitochondrial DNA (mtDNA) can be a powerful genetic marker for tracing origins and history of invasive populations. Here, we use mtDNA to address questions relevant to the understanding of invasion pathways of common starlings (Sturnus vulgaris) into Western Australia (WA) and discuss the utility of this marker to provide information useful to invasive species management. Mitochondrial sequence data indicate two geographically restricted genetic groups within Australia. Evidence of dispersal from genetically distinct sources outside the sampled range of starlings in Australia suggests increased vigilance by management agencies may be required to prevent further incursions from widely separated localities. Overall, genetic diversity in Australia was lower than in samples from the native range. Within Australia, genetic diversity was lowest in the most recently colonized area in the west, indicating that demographic bottlenecks have occurred in this area. Evidence of restricted dispersal between localities on the edge of the range expansion (ERE) in WA and other Australian sampling localities suggests that localized control within the ERE may be effective in preventing further range expansion. Signatures of spatial and demographic expansion are present in mismatch analyses from sampling localities located at the ERE, but neutrality indices did not support this finding, suggesting that the former may be more sensitive to recent expansion. Additionally, mismatch analyses support the presence of admixture, which is likely to have occurred pre-introduction. We compare our findings with those from a microsatellite study of the same samples and discuss how the mtDNA analyses used here offer valuable and unique insights into the invasion history of introduced species. © 2011 Blackwell Publishing Ltd.

Campbell S.,University of Melbourne | Campbell S.,Vertebrate Pest Research Section
Australian Zoologist | Year: 2011

Increasing exploitation of natural systems by humans is the driving force behind global devastation of biodiversity. Extinction risk is however not apportioned evenly across all taxa and specialist species are inherently more vulnerable compared to generalists. World-wide, 16 species of microchiropterans exhibit adaptations for specialist trawling foraging behaviours. Approximately half of these species are relatively well represented in the literature. Amongst these, the Large-footed Myotis, Myotis macropus, exhibits typical trawling bat behaviour; spending the majority (∼88%) of foraging time over water, feeding predominantly on aquatic prey items and selecting roosts close (>500m) to permanent water. These traits are broadly representative of all trawling bats and reflect convergence of the group on common, specialised behaviours. Such convergence places trawling bats at risk of very similar conservation threats, primarily disruptions to water-ways used for foraging, disturbance at cave roost sites and the possible reduction of suitable foraging habitat associated with aspects of human-enhanced climate change. These overarching conservation issues are highlighted by several studies of just a few species, but likely represent the same threats faced by all trawling bats, including those for which there is currently little published research available. Conservation of trawling bats world-wide will therefore benefit from actions that, in the least, address the common threats identified throughout this review.

Twigg L.E.,Vertebrate Pest Research Section | Parker R.W.,Alan Fletcher Research Station
Animal Welfare | Year: 2010

1080 (sodium fluoroacetate)-baiting programmes are an important and often the only option for reducing the impact of invasive vertebrate pests on biodiversity and agricultural production in Australia and New Zealand. These programmes are generally recognised as being target specific, and environmentally and user safe. Nevertheless, although 1080 has few recognised long-term side-effects, its potential to disrupt endocrine systems has been recently raised, and there is some conjecture regarding the humaneness of 1080 for certain target species. However, the assessment of the humaneness of any vertebrate pesticide must be commensurate with its mode of action, metabolism, target specificity, and operational use. This has not always occurred with 1080, particularly regarding these aspects, and its overall effects. The actual risk faced by non-target species during baiting operations is not accurately reflected simply by their sensitivity to 1080. 1080 is not endocrine-disrupting or carcinogenic, and because of the lag phase before signs of poisoning occur, the time from ingestion to death is not a reliable indicator of its humaneness. Moreover, functional receptors and neurological pathways are required to experience pain. However, as 1080 impairs neurological function, mainly through effects on acetylcholine and glutamate, and as this impairment includes some pain receptors, it is difficult to interpret the behaviour of affected animals, or to assess their ability to experience discomfort and pain. This has implications for assessing the merits of including ameliorative agents in 1080 baits aimed at further improving welfare outcomes. We also suggest that the assessment of the humaneness of any vertebrate pesticide should follow the ethical pest control approach, and on this basis, believe that the use of 1080 to reduce the detrimental impacts of invasive vertebrates is ethical, particularly with respect to the expectations of the wider community. © 2010 Universities Federation for Animal Welfare.

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