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Mike Letnic - One of the best experts on this subject based on the ideXlab platform.
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geographic hot spots of dingo genetic ancestry in southeastern australia despite hybridisation with domestic dogs
Conservation Genetics, 2020Co-Authors: Kylie M. Cairns, Mike Letnic, Bradley J Nesbitt, Shawn W Laffan, Mathew S CrowtherAbstract:Hybridisation resulting from human-driven shifts in species ranges is a global conservation concern. In Australia, hybridisation between Dingoes (Canis dingo) and domestic dogs (Canis familiaris) has been identified as an extinction threat to the dingo, and is thought to be particularly widespread in south-eastern Australia. Here, we investigated the extent of hybridisation between Dingoes and dogs in a sample of 783 wild-caught canids from eastern New South Wales, using an established 23-microsatellite test. We then mapped the distribution of these samples and identified three areas that are geographic hotspots of high dingo genetic ancestry using geospatial analysis. Between 9 and 23% of the wild canids that we sampled were classified as only having or likely to have only dingo ancestry. Only 0.6% of the wild canids we sampled were classified as having no dingo ancestry. Introgression from domestic dogs into the southeastern dingo gene pool has been extensive, with 76–88% of sampled Dingoes carrying some dog ancestry. Spatial analyses revealed several geographic hotspots of high dingo genetic ancestry within north-eastern New South Wales (NSW) where there was a higher than expected prevalence of Dingoes with no domestic dog ancestry. A key finding of our study is the observation of several regions where Dingoes were largely free of admixture from dogs. There is an ongoing need for evidence-based strategies to reduce human-driven hybridisation by identifying and maintaining natural barriers to reproduction or limiting opportunities for wild-domesticate hybridisation. Globally, legislators and land managers may need to consider less restrictive species definitions to conserve endangered or ecologically significant taxa.
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apex predators decouple population dynamics between mesopredators and their prey
Ecosystems, 2019Co-Authors: Anna Feit, Benjamin Feit, Mike LetnicAbstract:The mesopredator release hypothesis (MRH) predicts that the removal of apex predators should lead to increased abundance of smaller predators through relaxation of suppressive, top-down effects. However, apex predators’ effects on mesopredators are also likely to be modulated by interactions with human activities and ecosystem productivity. The exploitation ecosystems hypothesis (EEH) predicts that biomass of apex predators will scale with primary productivity but herbivore and mesopredator biomass will remain constant due to top-down control. Here, we take advantage of the manipulation of dingo abundance across Australia’s Dingo Fence to explore the primacy of top-down and bottom-up effects as drivers of feral cat abundance. Using field data collected across the Dingo Fence, we test the predictions generated by MRH and EEH that cat populations should be bottom-up controlled by prey abundance (a proxy for primary productivity) where top-down control exerted by Dingoes was weak but not where it was strong. We examined dingo and cat scats to provide mechanistic support for the idea that Dingoes control cats through killing and exploitative competition. Overall, cats were more abundant where Dingoes were rare. Cat abundance was correlated positively with prey abundance where Dingoes were rare but was not correlated with prey abundance where Dingoes were common. Cat remains were present in 1% of dingo scats, and dietary overlap between cats and Dingoes was high (0.75–0.82). Our study provides evidence that top-down control exerted by apex predators can decouple population dynamics between mesopredators and their prey and thus have primacy over bottom-up effects.
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indirect commensalism between an introduced apex predator and a native avian predator
Biodiversity and Conservation, 2019Co-Authors: James D Rees, Richard T Kingsford, Glenyss L Rees, Mike LetnicAbstract:In ecosystems, some organisms facilitate others indirectly, by interacting with one or more common mediator organisms. Thus, the indirect effects of introducing or removing species can be resonant, sometimes leading to successional extinctions. The dingo (Canis dingo) is the apex predator in Australian deserts and was introduced to the continent between 3000 and 5000 years ago. Dingoes suppress the abundances of introduced mesopredators, the red fox (Vulpes vulpes) and feral cat (Felis catus) and in so doing mitigate small mammal declines wreaked by these mesopredators. Given the positive association between the abundances of Dingoes and small mammals, we predicted that Dingoes indirectly facilitate a specialised native predator of small mammals, the Barn owl, Tyto alba. We tested our prediction by monitoring the abundances of Dingoes, foxes, cats, small mammals and barn owls and investigating barn owl diets in areas where Dingoes were common versus areas where Dingoes were functionally extinct on either side of the dingo barrier fence (DBF) in the Strzelecki Desert. Foxes and cats were less abundant in areas where Dingoes were common. Conversely, small mammals and barn owls were more abundant where Dingoes were common. Owls in areas where Dingoes were common fed almost exclusively on small mammals, but owls in areas where Dingoes were functionally extinct fed on greater proportion of birds and invertebrates. The findings of our study provide evidence that an introduced apex predator may indirectly facilitate a native predator and illustrates the myriad of far-reaching indirect effects that can result from apex predator suppression.
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Interactions between Dingoes and introduced wild ungulates: concepts, evidence and knowledge gaps
Australian Mammalogy, 2019Co-Authors: David M Forsyth, Mike Letnic, A. David M. Latham, Naomi E. Davis, Peter Caley, Paul D. Moloney, Luke Woodford, Andrew P. WoolnoughAbstract:The dingo (Canis dingo or C. familiaris, including hybrids with feral dogs) is the apex carnivore on mainland Australia. Fifteen non-native ungulate species have established wild populations in Australia. Dingoes are managed to reduce impacts on domestic ungulates, and introduced wild ungulates are managed to reduce impacts on natural ecosystems and to minimise competition with domestic ungulates. There is speculation about the extent to which (1) Dingoes limit the abundances of introduced wild ungulates, and (2) introduced wild ungulates sustain dingo populations. We reviewed the literature to identify potential ecological interactions between Dingoes and introduced wild ungulates, and to synthesise evidence for interactions between Dingoes and each ungulate species (including the percentage frequency occurrence (%FO) of ungulates in dingo diets). Eleven of the 15 ungulate species were recorded in the diet of Dingoes, with the highest %FO occurrences reported for feral goats (73%) and cattle (60%). Two studies concluded that Dingoes reduced ungulate abundances (feral goat (Capra hircus) and feral donkey (Equus asinus)), and two studies concluded that Dingoes did not regulate feral pig (Sus scrofa) abundances. A fifth study concluded that Dingoes exhibited a Type III functional response to increasing sambar deer (Cervus unicolor) abundances. A sixth study concluded that Dingoes made relatively little use of hunter-shot sambar deer carcasses. We propose that interactions between Dingoes and introduced wild ungulates depend on the sex–age classes vulnerable to dingo predation, dingo pack sizes, the availability of escape terrain for ungulates and the availability of alternative foods for Dingoes. The interplay between environmental conditions and the population growth rate of ungulates, and hence their ability to sustain losses from predation, could also be important. We predict that Dingoes will have most impact on the abundance of smaller ungulate species and neonates.
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Pets and pests: a review of the contrasting economics and fortunes of Dingoes and domestic dogs in Australia, and a proposed new funding scheme for non-lethal dingo management
Wildlife Research, 2019Co-Authors: Henry Brink, Mike Letnic, Robert G. Appleby, Brad V. Purcell, Hugh S. Webster, Neil R JordanAbstract:Carnivore conservation and management is complex and expensive, and significant ongoing management costs may inhibit the development of new tools and any subsequent transition away from lethal control. We review and compare the economic costs and benefits of Dingoes and domestic dogs in Australia and suggest that public affinity for domestic dogs may be co-opted into yielding more positive management outcomes for Dingoes. Whereas Australians spend over AU$10 billion annually on purchasing and maintaining 4.2 million domestic dogs, landowners and government spend at least AU$30 million attempting to limit the density and distribution of Dingoes, feral dogs, and their hybrids. These contrasting investments highlight the dual response of society towards domestic and wild members of the Canis genus. We suggest that a modest conservation levy on the sale of pet dogs or dog food, or both, could secure long-term funding to support efficacious non-lethal management of dingo impacts. A modest levy could generate AU$30 million annually, funding the development of non-lethal dingo-management tools without compromising existing management practices while new tools are investigated. Ultimately, a transition away from controlling Dingoes through culling or exclusion fencing, to managing the negative impacts of Dingoes could result in both more successful and sustainable management outcomes of Dingoes and support the ecological, cultural and economic benefits they confer as Australia’s apex predator.
Luke K.-p. Leung - One of the best experts on this subject based on the ideXlab platform.
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utilisation of stranded marine fauna washed ashore on k gari fraser island australia by Dingoes
Australian Journal of Zoology, 2018Co-Authors: Linda Behrendorff, Luke K.-p. Leung, Benjamin L. AllenAbstract:Stranded marine fauna have been identified as a potentially significant food resource for terrestrial carnivores, but how such subsidisation influences terrestrial species ecology is not well understood. We describe the dietary and behavioural responses of Dingoes (Canis familiaris) to the occurrence of large-animal marine strandings (e.g. dead cetaceans, marine turtles and pinnipeds) between 2006 and 2016 on K’gari (Fraser Island), Australia, to better understand the trophic links between marine and terrestrial systems. A total of 309 strandings were recorded during this period (~3.1 strandings per month), yielding an annual average of 30.3 tons of available carrion to the 100–200 Dingoes present on the island. Carcass monitoring with camera traps showed that Dingoes used carcasses almost daily after a short period of decomposition. Whole packs of up to seven Dingoes of all age classes at a time were observed visiting carcasses for multiple successive days. These data demonstrate that large-animal marine subsidies can be a common, substantial and important food source for Dingoes, and that the estimated daily dietary needs of roughly 5–10% of the island’s dingo population were supported by this food source. Our data suggest that marine subsidisation can influence terrestrial carnivore diet, behaviour and abundance, which may produce cascading indirect effects for terrestrial ecosystems in contexts where subsidised carnivores interact strongly with other species.
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Dingoes at the Doorstep: Home Range Sizes and Activity Patterns of Dingoes and Other Wild Dogs around Urban Areas of North-Eastern Australia
Animals : an open access journal from MDPI, 2016Co-Authors: Alice T. Mcneill, Luke K.-p. Leung, Mark Goullet, Matthew Gentle, Benjamin L. AllenAbstract:Top-predators around the world are becoming increasingly intertwined with humans, sometimes causing conflict and increasing safety risks in urban areas. In Australia, Dingoes and dingo×domesticdoghybridsarecommoninmanyurbanareas,andposeavarietyofhumanhealth and safety risks. However, data on urban dingo ecology is scant. We GPS-collared 37 Dingoes in north-easternAustraliaandcontinuouslymonitoredthemeach30minfor11-394days. MostDingoes were nocturnal, with an overall mean home range size of 17.47 km2. Overall mean daily distance travelled was 6.86 km/day. At all times Dingoes were within 1000 m of houses and buildings. Home ranges appeared to be constrained to patches of suitable vegetation fragments within and around human habitation. These data can be used to reallocate dingo management effort towards mitigating actual conflicts between humans and Dingoes in urban areas.
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Insects for breakfast and whales for dinner: the diet and body condition of Dingoes on Fraser Island (K’gari)
Scientific Reports, 2016Co-Authors: Linda Behrendorff, Luke K.-p. Leung, Allan Mckinnon, Jon Hanger, Grant Belonje, Jenna Tapply, Darryl Jones, Benjamin L. AllenAbstract:Top-predators play stabilising roles in island food webs, including Fraser Island, Australia. Subsidising generalist predators with human-sourced food could disrupt this balance, but has been proposed to improve the overall health of the island’s dingo ( Canis lupus dingo ) population, which is allegedly ‘starving’ or in ‘poor condition’. We assess this hypothesis by describing the diet and health of Dingoes on Fraser Island from datasets collected between 2001 and 2015. Medium-sized mammals (such as bandicoots) and fish were the most common food items detected in dingo scat records. Stomach contents records revealed additional information on diet, such as the occurrence of human-sourced foods. Trail camera records highlighted dingo utilisation of stranded marine fauna, particularly turtles and whales. Mean adult body weights were higher than the national average, body condition scores and abundant-excessive fat reserves indicated a generally ideal-heavy physical condition, and parasite loads were low and comparable to other dingo populations. These data do not support hypotheses that Fraser Island Dingoes have restricted diets or are in poor physical condition. Rather, they indicate that Dingoes on Fraser Island are capable of exploiting a diverse array of food sources which contributes to the vast majority of Dingoes being of good-excellent physical condition.
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diet of Dingoes and other wild dogs in peri urban areas of north eastern australia
Scientific Reports, 2016Co-Authors: Benjamin L. Allen, Mark Goullet, Matthew Gentle, Lee R. Allen, Erin Carmelito, Matthew Amos, James D M Speed, Luke K.-p. LeungAbstract:Knowledge of the resource requirements of urban predators can improve our understanding of their ecology and assist town planners and wildlife management agencies in developing management approaches that alleviate human-wildlife conflicts. Here we examine food and dietary items identified in scats of Dingoes in peri-urban areas of north-eastern Australia to better understand their resource requirements and the potential for Dingoes to threaten locally fragmented populations of native fauna. Our primary aim was to determine what peri-urban Dingoes eat, and whether or not this differs between regions. We identified over 40 different food items in dingo scats, almost all of which were mammals. Individual species commonly observed in dingo scats included agile wallabies, northern brown bandicoots and swamp wallabies. Birds were relatively common in some areas but not others, as were invertebrates. Dingoes were identified as a significant potential threat to fragmented populations of koalas. Dietary overlap was typically very high or near-identical between regions, indicating that peri-urban Dingoes ate the same types or sizes of prey in different areas. Future studies should seek to quantify actual and perceived impacts of, and human attitudes towards, peri-urban Dingoes, and to develop management strategies with a greater chance of reducing human-wildlife conflicts.
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interactions between two naturalised invasive predators in australia are feral cats suppressed by Dingoes
Biological Invasions, 2015Co-Authors: Benjamin L. Allen, Lee R. Allen, Luke K.-p. LeungAbstract:Top-predators can play important roles in terrestrial food webs, fuelling speculation that top-predators might be used as biocontrol tools against invasive mesopredators. Feral cats are believed to be largely responsible for the current declines of native fauna across tropical northern Australia, where substantial beef cattle production occurs. Dingoes are known to impact cattle production there and are predicted to impact native fauna also. However, Dingoes are forecasted to curtail the impacts of cats and reverse native fauna declines. We review (1) empirical studies investigating the relationships between Dingoes and cats, and dingo control and cats, (2) records of cat remains in dingo diets, and (3) historical records of lethal dingo control using 1080-poisoned baits across Australia between 1999 and 2008 to show how two naturalised invasive species can interact in dynamic agro-ecological landscapes. From the 35 studies assessed, most reported no detectable relationship between Dingoes and cats; negative or positive relationships were seldom detected. Dingoes do not appear to exclude cats beyond fine scales, but may alter cat activity periods under certain conditions. Cat remains were found in only 0.63 % of over 31,000 dingo diet records. Lethal dingo control occurs (in varying degrees) across about two-thirds of Australia and does not appear to substantially influence dingo-cat relationships. We conclude that the presently available data provides little evidence that bolstering dingo populations will reduce the impacts of cats. Much more work is needed to identify situations where top-predators might be used as effective biocontrol tools against invasive mesopredators in agro-ecological systems.
Benjamin L. Allen - One of the best experts on this subject based on the ideXlab platform.
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utilisation of stranded marine fauna washed ashore on k gari fraser island australia by Dingoes
Australian Journal of Zoology, 2018Co-Authors: Linda Behrendorff, Luke K.-p. Leung, Benjamin L. AllenAbstract:Stranded marine fauna have been identified as a potentially significant food resource for terrestrial carnivores, but how such subsidisation influences terrestrial species ecology is not well understood. We describe the dietary and behavioural responses of Dingoes (Canis familiaris) to the occurrence of large-animal marine strandings (e.g. dead cetaceans, marine turtles and pinnipeds) between 2006 and 2016 on K’gari (Fraser Island), Australia, to better understand the trophic links between marine and terrestrial systems. A total of 309 strandings were recorded during this period (~3.1 strandings per month), yielding an annual average of 30.3 tons of available carrion to the 100–200 Dingoes present on the island. Carcass monitoring with camera traps showed that Dingoes used carcasses almost daily after a short period of decomposition. Whole packs of up to seven Dingoes of all age classes at a time were observed visiting carcasses for multiple successive days. These data demonstrate that large-animal marine subsidies can be a common, substantial and important food source for Dingoes, and that the estimated daily dietary needs of roughly 5–10% of the island’s dingo population were supported by this food source. Our data suggest that marine subsidisation can influence terrestrial carnivore diet, behaviour and abundance, which may produce cascading indirect effects for terrestrial ecosystems in contexts where subsidised carnivores interact strongly with other species.
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Intraspecific killing behaviour of canids: how Dingoes kill Dingoes
Ethology Ecology & Evolution, 2017Co-Authors: Linda Behrendorff, Grant Belonje, Benjamin L. AllenAbstract:Intraspecific conflict is an important process structuring carnivore populations. However, few data are available describing the precise mode of killing used by carnivores, especially medium-sized carnivores that can exhibit behaviours typically associated with either smaller or larger species. From records of free-ranging Australian Dingoes killed during intraspecific fighting, we describe the types, location and frequency of injuries sustained, to assist in identifying killing behaviours common to medium-sized carnivores, or mesopredators. Observed injuries included superficial minor cuts and other wounds, deep punctures (bite marks or holes), severe lacerations to internal organs, tissue bruising and crushing, mutilation of muscle tissue, perforation of the chest and abdominal cavities, and a variety of bone fractures. The Dingoes in this study predominately died from gross internal haemorrhaging caused by crushing bites coupled with vigorous shaking to the head, throat, neck and ventral chest areas. O...
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Dingoes at the Doorstep: Home Range Sizes and Activity Patterns of Dingoes and Other Wild Dogs around Urban Areas of North-Eastern Australia
Animals : an open access journal from MDPI, 2016Co-Authors: Alice T. Mcneill, Luke K.-p. Leung, Mark Goullet, Matthew Gentle, Benjamin L. AllenAbstract:Top-predators around the world are becoming increasingly intertwined with humans, sometimes causing conflict and increasing safety risks in urban areas. In Australia, Dingoes and dingo×domesticdoghybridsarecommoninmanyurbanareas,andposeavarietyofhumanhealth and safety risks. However, data on urban dingo ecology is scant. We GPS-collared 37 Dingoes in north-easternAustraliaandcontinuouslymonitoredthemeach30minfor11-394days. MostDingoes were nocturnal, with an overall mean home range size of 17.47 km2. Overall mean daily distance travelled was 6.86 km/day. At all times Dingoes were within 1000 m of houses and buildings. Home ranges appeared to be constrained to patches of suitable vegetation fragments within and around human habitation. These data can be used to reallocate dingo management effort towards mitigating actual conflicts between humans and Dingoes in urban areas.
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Insects for breakfast and whales for dinner: the diet and body condition of Dingoes on Fraser Island (K’gari)
Scientific Reports, 2016Co-Authors: Linda Behrendorff, Luke K.-p. Leung, Allan Mckinnon, Jon Hanger, Grant Belonje, Jenna Tapply, Darryl Jones, Benjamin L. AllenAbstract:Top-predators play stabilising roles in island food webs, including Fraser Island, Australia. Subsidising generalist predators with human-sourced food could disrupt this balance, but has been proposed to improve the overall health of the island’s dingo ( Canis lupus dingo ) population, which is allegedly ‘starving’ or in ‘poor condition’. We assess this hypothesis by describing the diet and health of Dingoes on Fraser Island from datasets collected between 2001 and 2015. Medium-sized mammals (such as bandicoots) and fish were the most common food items detected in dingo scat records. Stomach contents records revealed additional information on diet, such as the occurrence of human-sourced foods. Trail camera records highlighted dingo utilisation of stranded marine fauna, particularly turtles and whales. Mean adult body weights were higher than the national average, body condition scores and abundant-excessive fat reserves indicated a generally ideal-heavy physical condition, and parasite loads were low and comparable to other dingo populations. These data do not support hypotheses that Fraser Island Dingoes have restricted diets or are in poor physical condition. Rather, they indicate that Dingoes on Fraser Island are capable of exploiting a diverse array of food sources which contributes to the vast majority of Dingoes being of good-excellent physical condition.
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diet of Dingoes and other wild dogs in peri urban areas of north eastern australia
Scientific Reports, 2016Co-Authors: Benjamin L. Allen, Mark Goullet, Matthew Gentle, Lee R. Allen, Erin Carmelito, Matthew Amos, James D M Speed, Luke K.-p. LeungAbstract:Knowledge of the resource requirements of urban predators can improve our understanding of their ecology and assist town planners and wildlife management agencies in developing management approaches that alleviate human-wildlife conflicts. Here we examine food and dietary items identified in scats of Dingoes in peri-urban areas of north-eastern Australia to better understand their resource requirements and the potential for Dingoes to threaten locally fragmented populations of native fauna. Our primary aim was to determine what peri-urban Dingoes eat, and whether or not this differs between regions. We identified over 40 different food items in dingo scats, almost all of which were mammals. Individual species commonly observed in dingo scats included agile wallabies, northern brown bandicoots and swamp wallabies. Birds were relatively common in some areas but not others, as were invertebrates. Dingoes were identified as a significant potential threat to fragmented populations of koalas. Dietary overlap was typically very high or near-identical between regions, indicating that peri-urban Dingoes ate the same types or sizes of prey in different areas. Future studies should seek to quantify actual and perceived impacts of, and human attitudes towards, peri-urban Dingoes, and to develop management strategies with a greater chance of reducing human-wildlife conflicts.
Mathew S Crowther - One of the best experts on this subject based on the ideXlab platform.
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geographic hot spots of dingo genetic ancestry in southeastern australia despite hybridisation with domestic dogs
Conservation Genetics, 2020Co-Authors: Kylie M. Cairns, Mike Letnic, Bradley J Nesbitt, Shawn W Laffan, Mathew S CrowtherAbstract:Hybridisation resulting from human-driven shifts in species ranges is a global conservation concern. In Australia, hybridisation between Dingoes (Canis dingo) and domestic dogs (Canis familiaris) has been identified as an extinction threat to the dingo, and is thought to be particularly widespread in south-eastern Australia. Here, we investigated the extent of hybridisation between Dingoes and dogs in a sample of 783 wild-caught canids from eastern New South Wales, using an established 23-microsatellite test. We then mapped the distribution of these samples and identified three areas that are geographic hotspots of high dingo genetic ancestry using geospatial analysis. Between 9 and 23% of the wild canids that we sampled were classified as only having or likely to have only dingo ancestry. Only 0.6% of the wild canids we sampled were classified as having no dingo ancestry. Introgression from domestic dogs into the southeastern dingo gene pool has been extensive, with 76–88% of sampled Dingoes carrying some dog ancestry. Spatial analyses revealed several geographic hotspots of high dingo genetic ancestry within north-eastern New South Wales (NSW) where there was a higher than expected prevalence of Dingoes with no domestic dog ancestry. A key finding of our study is the observation of several regions where Dingoes were largely free of admixture from dogs. There is an ongoing need for evidence-based strategies to reduce human-driven hybridisation by identifying and maintaining natural barriers to reproduction or limiting opportunities for wild-domesticate hybridisation. Globally, legislators and land managers may need to consider less restrictive species definitions to conserve endangered or ecologically significant taxa.
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the dingo menace an historic survey on graziers management of an australian carnivore
Pacific Conservation Biology, 2019Co-Authors: Lily M Van Eeden, Mathew S Crowther, Bradley P. Smith, Chris R Dickman, Thomas M. NewsomeAbstract:Studies of environmental history provide an important lens through which to analyse our contemporary thinking and practices. Here we consider historic management of the conflict caused by dingo predation on livestock. We present unpublished findings of a comprehensive national survey of graziers’ attitudes, knowledge and interactions with Dingoes that was conducted by Professor N. W. G. Macintosh in the 1950s. By analysing the 137 responses from this survey, we sought to determine the factors that shaped graziers’ attitudes and management decisions. The four most popular management methods employed to protect livestock from Dingoes were trapping (80%), ground-baiting (68%), fencing (44%), and shooting (34%). Whether a respondent had sheep or not was the strongest determinant of which management methods were used, with sheep graziers less likely to use ground-baiting and shooting and more likely to use trapping and fencing. While some patterns among responses were evident, the study reveals the complex nature of graziers’ experiences with Dingoes and suggests that, given the lack of scientific evidence available to them at the time of Macintosh’s survey, their decisions, observations, and attitudes were influenced by contextual factors. We use this analysis to consider how history has shaped contemporary dingo management. While the economic, social and environmental context has changed since Macintosh’s survey over 60 years ago, some historical attitudes and practices surrounding Dingoes have endured and attacks on livestock by Dingoes continue to be regarded as a major threat to graziers.
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resolving the value of the dingo in ecological restoration
Restoration Ecology, 2015Co-Authors: Mathew S Crowther, Thomas M. Newsome, Peter J. S. Fleming, Guy Ballard, Justin A Dellinger, Alistair S Glen, Aaron C Greenville, Christopher N. JohnsonAbstract:There is global interest in restoring populations of apex predators, both to conserve them and to harness their ecological services. In Australia, reintroduction of Dingoes (Canis dingo) has been proposed to help restore degraded rangelands. This proposal is based on theories and the results of studies suggesting that Dingoes can suppress populations of prey (especially medium- and large-sized herbivores) and invasive predators such as red foxes (Vulpes vulpes) and feral cats (Felis catus) that prey on threatened native species. However, the idea of dingo reintroduction has met opposition, especially from scientists who query the dingo's positive effects for some species or in some environments. Here, we ask ‘what is a feasible experimental design for assessing the role of Dingoes in ecological restoration?’ We outline and propose a dingo reintroduction experiment—one that draws upon the existing dingo-proof fence—and identify an area suitable for this (Sturt National Park, western New South Wales). Although challenging, this initiative would test whether Dingoes can help restore Australia's rangeland biodiversity, and potentially provide proof-of-concept for apex predator reintroductions globally.
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an updated description of the australian dingo canis dingo meyer 1793
Journal of Zoology, 2014Co-Authors: Mathew S Crowther, Nick J Colman, Melanie Fillios, Mike LetnicAbstract:A sound understanding of the taxonomy of threatened species is essential for setting conservation priorities and the development of management strategies. Hybridization is a threat to species conservation because it compromises the integrity of unique evolutionary lineages and can impair the ability of conservation managers to identify threatened taxa and achieve conservation targets. Australia’s largest land predator, the dingo Canis dingo, is a controversial taxon that is threatened by hybridization. Since their arrival <5000 yBP (years Before Present) Dingoes have been subject to isolation, leading to them becoming a unique canid. However, the dingo’s taxonomic status is clouded by hybridization with modern domesticated dogs and confusion about how to distinguish ‘pure’ Dingoes from dingo-dog hybrids. Confusion exists because there is no description or series of original specimens against which the identities of putative hybrid and ‘pure’ Dingoes can be assessed. Current methods to classify Dingoes have poor discriminatory abilities because natural variation within Dingoes is poorly understood, and it is unknown if hybridization may have altered the genome of post19th century reference specimens. Here we provide a description of the dingo based on pre-20th century specimens that are unlikely to have been influenced by hybridization. The dingo differs from the domestic dog by relatively larger palatal width, relatively longer rostrum, relatively shorter skull height and relatively wider top ridge of skull. A sample of 19th century dingo skins we examined suggests that there was considerable variability in the colour of Dingoes and included various combinations of yellow, white, ginger and darker variations from tan to black. Although it remains difficult to provide consistent and clear diagnostic features, our study places morphological limits on what can be considered a dingo.
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dietary niche overlap of free roaming Dingoes and domestic dogs the role of human provided food
Journal of Mammalogy, 2014Co-Authors: Mathew S Crowther, Thomas M. Newsome, Peter J. S. Fleming, Guy Ballard, Chris R DickmanAbstract:As both companion animals and opportunistic predators, dogs (Canis lupus spp.) have had a long and complex relationship with humans. In Australia, the dingo (C. l. dingo) was introduced 4,000 years ago and, other than humans, is now the continent's top mammalian predator. Domestic dogs (C. l. familiaris) were introduced by Europeans more recently and they interbreed with Dingoes. This hybridization has caused growing concern about the roles that domestic dogs and Dingoes play in shaping ecosystem processes. There is also considerable debate about whether anthropogenic environmental changes can alter the ecological roles of Dingoes. We used scat analysis to test whether the dingo, as the longer-established predator, occupies a different dietary niche from that of free-roaming domestic dogs, irrespective of human influence. Our results demonstrate considerable dietary overlap between Dingoes and domestic dogs in areas where humans provide supplementary food, providing evidence against our hypothesis. However, the consumption by Dingoes of a greater diversity of prey, in association with historical differences in the interactions between Dingoes and humans, suggests a partial separation of their dietary niche from that of domestic dogs. We conclude that anthropogenic changes in resource availability could prevent Dingoes from fulfilling their trophic regulatory or pre-European roles. Effective management of human-provided food is therefore required urgently to minimize the potential for subsidized populations of Dingoes and domestic dogs to negatively affect co-occurring prey.
Euan G Ritchie - One of the best experts on this subject based on the ideXlab platform.
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interspecific and geographic variation in the diets of sympatric carnivores Dingoes wild dogs and red foxes in south eastern australia
PLOS ONE, 2015Co-Authors: Naomi E. Davis, David M Forsyth, Euan G Ritchie, Barbara Triggs, Charlie Pascoe, Joe Benshemesh, Alan Robley, Jenny Lawrence, Dale G Nimmo, Lindy LumsdenAbstract:Dingoes/wild dogs (Canis dingo/familiaris) and red foxes (Vulpes vulpes) are widespread carnivores in southern Australia and are controlled to reduce predation on domestic livestock and native fauna. We used the occurrence of food items in 5875 dingo/wild dog scats and 11,569 fox scats to evaluate interspecific and geographic differences in the diets of these species within nine regions of Victoria, south-eastern Australia. The nine regions encompass a wide variety of ecosystems. Diet overlap between Dingoes/wild dogs and foxes varied among regions, from low to near complete overlap. The diet of foxes was broader than Dingoes/wild dogs in all but three regions, with the former usually containing more insects, reptiles and plant material. By contrast, Dingoes/wild dogs more regularly consumed larger mammals, supporting the hypothesis that niche partitioning occurs on the basis of mammalian prey size. The key mammalian food items for Dingoes/wild dogs across all regions were black wallaby (Wallabia bicolor), brushtail possum species (Trichosurus spp.), common wombat (Vombatus ursinus), sambar deer (Rusa unicolor), cattle (Bos taurus) and European rabbit (Oryctolagus cuniculus). The key mammalian food items for foxes across all regions were European rabbit, sheep (Ovis aries) and house mouse (Mus musculus). Foxes consumed 6.1 times the number of individuals of threatened Critical Weight Range native mammal species than did Dingoes/wild dogs. The occurrence of intraguild predation was asymmetrical; Dingoes/wild dogs consumed greater biomass of the smaller fox. The substantial geographic variation in diet indicates that Dingoes/wild dogs and foxes alter their diet in accordance with changing food availability. We provide checklists of taxa recorded in the diets of Dingoes/wild dogs and foxes as a resource for managers and researchers wishing to understand the potential impacts of policy and management decisions on Dingoes/wild dogs, foxes and the food resources they interact with.
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A comment on the influence of Dingoes on the Australian sheep flock
Australian veterinary journal, 2014Co-Authors: David M Forsyth, Euan G Ritchie, M. Kennedy, Andrew P. Woolnough, Dale G Nimmo, A Pople, I WatsonAbstract:fAllen and West recently proposed that Dingoes (Canis dingo, including hybrids with feral dogs C. lupus familiaris) are a critical causal factor in the decline of Australia’s sheep (Ovis aries) flock and implied that Dingoes would cause the rangeland sheep industry to disappear within 30−40 years. 1 We agree that dingo predation can reduce the profitability of affected sheep properties and has important negative social effect on rural communities, and that exclusion fences and a range of lethal control methods are options for reducing those negative effects. However, we argue that the importance of Dingoes as a cause of the decline in Australia’s sheep flock has been overstated.
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effects of predator control on behaviour of an apex predator and indirect consequences for mesopredator suppression
Journal of Applied Ecology, 2012Co-Authors: Leila A Brook, Christopher N. Johnson, Euan G RitchieAbstract:1. Apex predators can benefit ecosystems through top–down control of mesopredators and herbivores. However, apex predators are often subject to lethal control aimed at minimizing attacks on livestock. Lethal control can affect both the abundance and behaviour of apex predators. These changes could in turn influence the abundance and behaviour of mesopredators. 2. We used remote camera surveys at nine pairs of large Australian rangeland properties, comparing properties that controlled Dingoes Canis lupus dingo with properties that did not, to test the effects of predator control on dingo activity and to evaluate the responses of a mesopredator, the feral cat Felis catus. 3. Indices of dingo abundance were generally reduced on properties that practiced dingo control, in comparison with paired properties that did not, although the effect size of control was variable. Dingoes in uncontrolled populations were crepuscular, similar to major prey. In populations subject to control, Dingoes became less active around dusk, and activity was concentrated in the period shortly before dawn. 4. Shifts in feral cat abundance indices between properties with and without dingo control were inversely related to corresponding shifts in indices of dingo abundance. There was also a negative relationship between predator visitation rates at individual camera stations, suggesting cats avoided areas where Dingoes were locally common. Reduced activity by Dingoes at dusk was associated with higher activity of cats at dusk. 5. Our results suggest that effective dingo control not only leads to higher abundance of feral cats, but allows them to optimize hunting behaviour when Dingoes are less active. This double effect could amplify the impacts of dingo control on prey species selected by cats. In areas managed for conservation, stable dingo populations may thus contribute to management objectives by restricting feral cat access to prey populations. 6. Synthesis and applications. Predator control not only reduces indices of apex predator abundance but can also modify their behaviour. Hence, indicators other than abundance, such as behavioural patterns, should be considered when estimating a predator's capacity to effectively interact with lower trophic guilds. Changes to apex predator behaviour may relax limitations on the behaviour of mesopredators, providing enhanced access to resources and prey.
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Top predators as biodiversity regulators: the dingo Canis lupus dingo as a case study.
Biological reviews of the Cambridge Philosophical Society, 2011Co-Authors: Mike Letnic, Euan G Ritchie, Chris R DickmanAbstract:Top-order predators often have positive effects on biological diversity owing to their key functional roles in regulating trophic cascades and other ecological processes. Their loss has been identified as a major factor contributing to the decline of biodiversity in both aquatic and terrestrial systems. Consequently, restoring and maintaining the ecological function of top predators is a critical global imperative. Here we review studies of the ecological effects of the dingo Canis lupus dingo, Australia's largest land predator, using this as a case study to explore the influence of a top predator on biodiversity at a continental scale. The dingo was introduced to Australia by people at least 3500 years ago and has an ambiguous status owing to its brief history on the continent, its adverse impacts on livestock production and its role as an ecosystem architect. A large body of research now indicates that Dingoes regulate ecological cascades, particularly in arid Australia, and that the removal of Dingoes results in an increase in the abundances and impacts of herbivores and invasive mesopredators, most notably the red fox Vulpes vulpes. The loss of Dingoes has been linked to widespread losses of small and medium-sized native mammals, the depletion of plant biomass due to the effects of irrupting herbivore populations and increased predation rates by red foxes. We outline a suite of conceptual models to describe the effects of Dingoes on vertebrate populations across different Australian environments. Finally, we discuss key issues that require consideration or warrant research before the ecological effects of Dingoes can be incorporated formally into biodiversity conservation programs.
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demonising the dingo how much wild dogma is enough
Current Zoology, 2011Co-Authors: Mike Letnic, Mathew S Crowther, Chris R Dickman, Euan G RitchieAbstract:The roles that top predators play in regulating the structure and function of ecosystems have long been controversial. This is particularly the case when predators pose adverse risks for human life and/or economic interests. The critique of literature on Dingoes and their ecological roles in Australia provided by Allen et al. (2011) shows that top predators remain a potentially polarising issue. In opposition to Allen et al. we argue that these widespread patterns of species’ abundances, attributed to the effects of Dingoes and evident at scales ranging from the foraging behaviour of individuals through to continental scale patterns of species abundances, constitute strong support for the mesopredator release hypothesis and provide evidence that Dingoes benefit biodiversity conservation by inducing community wide trophic cascades. Harnessing the positive ecological effects of Dingoes while at the same time minimising their impacts on agriculture is a major socio-political challenge in Australia [Current Zoology 57 (5): 668-670].