Vigilance is an important anti‐predator behaviour that can be an indicator of the predation risk ... more Vigilance is an important anti‐predator behaviour that can be an indicator of the predation risk faced by potential prey animals. Here, we assess the collective vigilance, or the vigilance level of an entire group, of corvids (Family: Corvidae) at experimentally placed carcasses in a desert environment in Australia. Specifically, we explore the relationship between collective vigilance levels and the habitat in which the carcass was placed, the time since a potential predator (dingo Canis dingo, wedge‐tailed eagle Aquila audax or red fox Vulpes vulpes) was present at a carcass, and the group size of corvids around the carcass. We found that corvids are more vigilant in open habitat, but that group size and the recent presence of a potential predator does not affect the collective vigilance behaviour of corvids. The results demonstrate the important link between habitat and vigilance, and that animals may adopt anti‐predator behaviours irrespective of the size of the group in which t...
Carrion is an ubiquitous resource that drives the dynamics of scavenger populations and shapes th... more Carrion is an ubiquitous resource that drives the dynamics of scavenger populations and shapes the structure and composition of their communities. Corvids (Family: Corvidae) are among the most common scavengers globally, facilitating carcass discovery by other species and contributing to carcass biomass removal. Here, we examine how environmental factors influence corvid scavenging dynamics in an arid region of Central Australia. Specifically, we investigate how habitat, season and a major flood event affect corvid discovery and visitation time, and group size around carcass sites. To do so, we used data collected from camera traps monitoring 80 experimentally positioned red kangaroo (Osphranter rufus) carcasses stratified across closed and open habitats, spring and winter seasons, and before and after a flood event. Corvids took longer to discover carcasses in closed compared to open habitats, but habitat did not affect how long corvids spent visiting carcasses, or corvid group siz...
Abstract In addition to feeding on animal remains, many scavengers also function as predators. Ca... more Abstract In addition to feeding on animal remains, many scavengers also function as predators. Carcasses may therefore affect local animal communities by attracting facultative scavengers and increasing predation risk for other species in the vicinity of the carcasses. This risk may be elevated in low productivity environments, especially where humans increase carcass production and where facultative scavengers include invasive species. In June and October 2018, we monitored experimentally placed red kangaroo (Osphranter rufus) carcasses and artificial bird nests in two different habitats in the Simpson Desert, Australia, to identify the nest predators attracted to the carcasses, and to determine how carcasses affect overall and predator-specific nest predation. We modelled our nests to approximate those of the ground nesting little buttonquail (Turnix velox) and the endangered night parrot (Pezoporus occidentalis). Native Corvus spp. and then invasive red foxes (Vulpes vulpes) were the top carcass visitors and nest egg predators. Carcass presence and open habitat increased overall nest predation and fewer artificial parrot nest eggs were depredated compared to those of quail. Open habitat and carcass presence only increased predator-specific nest predation by foxes, but corvid nest predation was highest in June 2018, and for the artificial quail nest types. Foxes were the main predator of eggs from night parrot nests. Our study shows that carcass provisioning by humans may have indirect, deleterious effects on ground nesting birds, and indicates that foxes might pose a greater threat to night parrot populations than previously recognised.
Public opposition has shaped management of wild animals in Australia, but public interest in ding... more Public opposition has shaped management of wild animals in Australia, but public interest in dingo control has been minimal. We hypothesised that this is due to lack of awareness of dingo management practices, in part because using the term “wild dogs” to describe management renders “dingoes” invisible, framing the issue as one of control of introduced pests rather than control of an iconic Australian animal. We distributed an online questionnaire survey to the Australian public (N = 811) to measure how the public perceived dingoes and their management, how these views compared with other animals managed as pests in Australia, and whether the term “wild dogs” has shaped views and knowledge of dingo management. Most respondents (84.6%) considered dingoes to be native to Australia and there was low approval of lethal control methods, except when justification was provided (e.g., to protect livestock or endangered native species). Only 19.1% were aware that “wild dog” management includ...
Livestock producers and governments have managed predators to protect livestock for millennia. Bu... more Livestock producers and governments have managed predators to protect livestock for millennia. But in recent decades attitudes towards predators and their management have shifted from solely killing towards coexistence and even conservation. In Australia, a continent-wide survey of graziers conducted in the 1950s provides an opportunity to consider how attitudes and practices surrounding dingo management have changed over the last 60 years. We created a survey that repeated questions and themes from the 1950s study and sent this to 75 of the properties where the original survey had been completed. We received 23 complete or semicomplete responses. Ground-baiting and shooting continue to form a major focus of management on the focal properties, while fewer respondents used trapping and fencing in the current survey than in the 1950s. Ten properties had adopted either or both of two lethal methods (aerial baiting and hiring professional doggers) since the 1950s survey. Unlike the 1950...
Studies of environmental history provide an important lens through which to analyse our contempor... more 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 re...
Carnivore predation on livestock often leads people to retaliate. Persecution by humans has contr... more Carnivore predation on livestock often leads people to retaliate. Persecution by humans has contributed strongly to global endangerment of carnivores. Preventing livestock losses would help to achieve three goals common to many human societies: preserve nature, protect animal welfare, and safeguard human livelihoods. Between 2016 and 2018, four independent reviews evaluated >40 years of research on lethal and nonlethal interventions for reducing predation on livestock. From 114 studies, we find a striking conclusion: scarce quantitative comparisons of interventions and scarce comparisons against experimental controls preclude strong inference about the effectiveness of methods. For wise investment of public resources in protecting livestock and carnivores, evidence of effectiveness should be a prerequisite to policy making or large-scale funding of any method or, at a minimum, should be measured during implementation. An appropriate evidence base is needed, and we recommend a coa...
ABSTRACT Australia has a range of native and introduced large herbivores that could affect the ab... more ABSTRACT Australia has a range of native and introduced large herbivores that could affect the abundance of small mammals through direct and indirect effects. Here we study the relationship between occurrence of the introduced rusa deer (Rusa timorensis) and the native swamp wallaby (Wallabia bicolor), and the abundance of four species of native small mammals in coastal heath vegetation with varying fire history.The abundance of two species, the brown antechinus (Antechinus stuartii) and bush rat (Rattus fuscipes), was related to occurrence of large herbivores and was dependent also on fire history. Abundance of swamp rats (R. lutreolus) and New Holland mice (Pseudomys novaehollandiae) was not related to the occurrence of any of the large herbivores, and did not depend on fire history. At sites burned within the last 9 years, captures of brown antechinus were negatively related to both deer and wallaby occurrence, and captures of bush rats were negatively related to deer occurrence. However, at sites that burned more than 15 years ago, captures of brown antechinus and bush rats were not related to large herbivore occurrence. Overall there was either no relationship, or a negative one, between small mammals and the large herbivores.This mensurative study has demonstrated relationships between deer and wallabies and small mammals, with fire as an additional important factor. From the results of the current study we put forward a series of hypotheses that need to be tested by future experiments.
Choosing the appropriate method to detect and monitor wildlife species is difficult if the specie... more Choosing the appropriate method to detect and monitor wildlife species is difficult if the species is rare or cryptic in appearance or behaviour. We evaluated the effectiveness of the following four methods for detecting red foxes (Vulpes vulpes) on the basis of equivalent person hours in a rural landscape in temperate Australia: camera traps, hair traps (using morphology and DNA from hair follicles), scats from bait stations (using DNA derived from the scats) and spotlighting. We also evaluated whether individual foxes could be identified using remote collection of their tissues. Genetic analysis of hair samples was the least efficient method of detection among the methods employed because of the paucity of samples obtained and the lack of follicles on sampled hairs. Scat detection was somewhat more efficient. Scats were deposited at 17% of bait stations and 80% of scats were amplified with a fox-specific marker, although only 31% of confirmed fox scats could be fully genotyped at ...
Proceedings of the Royal Society B: Biological Sciences, 2009
Alien predators can have catastrophic effects on ecosystems and are thought to be much more harmf... more Alien predators can have catastrophic effects on ecosystems and are thought to be much more harmful to biodiversity than their native counterparts. However, trophic cascade theory and the mesopredator release hypothesis predict that the removal of top predators will result in the reorganization of trophic webs and loss of biodiversity. Using field data collected throughout arid Australia, we provide evidence that removal of an alien top-predator, the dingo, has cascading effects through lower trophic levels. Dingo removal was linked to increased activity of herbivores and an invasive mesopredator, the red fox ( Vulpes vulpes ), and to the loss of grass cover and native species of small mammals. Using species distribution data, we predict that reintroducing or maintaining dingo populations would produce a net benefit for the conservation of threatened native mammals across greater than 2.42 × 10 6 km 2 of Australia. Our study provides evidence that an alien top predator can assume a ...
Mating in the marsupial genus Antechinus is a synchronous annual event that is characterized by m... more Mating in the marsupial genus Antechinus is a synchronous annual event that is characterized by monoestry in females and abrupt postmating mortality in males. Male semelparity (multiple copulations during a single breeding season per lifetime) is often assumed to occur as a consequence of the intense mating effort expended by males in the rut, but the forces selecting for this remain elusive. Here, we investigate selection in male brown antechinus, Antechinus stuartii, and test two hypotheses for the evolution of semelparity: intermale competition and sperm competition. If intermale competition drives semelparity, we predicted that males would be under strong selection for large body size. If sperm competition is important, we predicted that selection would be strongest on scrotal size, a surrogate for testes volume. Using microsatellite markers, we found that 92% of females in free‐living conditions mated with multiple males, producing litters of eight that had up to four fathers. ...
Aim To determine whether latitudinal and longitudinal gradients in seed mass are related to vari... more Aim To determine whether latitudinal and longitudinal gradients in seed mass are related to variation in climatic features including temperature, solar radiation and rainfall.Location Australia.Methods Seed mass was estimated from over 1600 provenances covering the latitudinal and longitudinal extents of 34 perennial Glycine taxa in Australia. Climatic data were obtained from ANUCLIM 5.1 for collection locations based on long‐term meteorological records across Australia. These climatic data were subject to principal components analysis to extract three components as climatic indices. Generalized linear models were used in three separate sets of analyses to evaluate whether seed mass–latitude and seed mass–longitude relationships persisted after taking climatic variation into account. First, relationships were examined across species in analyses that did not explicitly consider phylogenetic relationships. Secondly, phylogenetic regressions were performed to examine patterns of cor...
The introduction of invasive alien predators often has catastrophic effects on populations of naï... more The introduction of invasive alien predators often has catastrophic effects on populations of naïve native prey, but in situations where prey survive the initial impact a predator may act as a strong selective agent for prey that can discriminate and avoid it. Using two common species of Australian small mammals that have persisted in the presence of an alien predator, the European red fox Vulpes vulpes, for over a century, we hypothesised that populations of both would perform better where the activity of the predator was low than where it was high and that prey individuals would avoid signs of the predator's presence. We found no difference in prey abundance in sites with high and low fox activity, but survival of one species-the bush rat Rattus fuscipes-was almost twofold higher where fox activity was low. Juvenile, but not adult rats, avoided fox odour on traps, as did individuals of the second prey species, the brown antechinus, Antechinus stuartii. Both species also showe...
Vigilance is an important anti‐predator behaviour that can be an indicator of the predation risk ... more Vigilance is an important anti‐predator behaviour that can be an indicator of the predation risk faced by potential prey animals. Here, we assess the collective vigilance, or the vigilance level of an entire group, of corvids (Family: Corvidae) at experimentally placed carcasses in a desert environment in Australia. Specifically, we explore the relationship between collective vigilance levels and the habitat in which the carcass was placed, the time since a potential predator (dingo Canis dingo, wedge‐tailed eagle Aquila audax or red fox Vulpes vulpes) was present at a carcass, and the group size of corvids around the carcass. We found that corvids are more vigilant in open habitat, but that group size and the recent presence of a potential predator does not affect the collective vigilance behaviour of corvids. The results demonstrate the important link between habitat and vigilance, and that animals may adopt anti‐predator behaviours irrespective of the size of the group in which t...
Carrion is an ubiquitous resource that drives the dynamics of scavenger populations and shapes th... more Carrion is an ubiquitous resource that drives the dynamics of scavenger populations and shapes the structure and composition of their communities. Corvids (Family: Corvidae) are among the most common scavengers globally, facilitating carcass discovery by other species and contributing to carcass biomass removal. Here, we examine how environmental factors influence corvid scavenging dynamics in an arid region of Central Australia. Specifically, we investigate how habitat, season and a major flood event affect corvid discovery and visitation time, and group size around carcass sites. To do so, we used data collected from camera traps monitoring 80 experimentally positioned red kangaroo (Osphranter rufus) carcasses stratified across closed and open habitats, spring and winter seasons, and before and after a flood event. Corvids took longer to discover carcasses in closed compared to open habitats, but habitat did not affect how long corvids spent visiting carcasses, or corvid group siz...
Abstract In addition to feeding on animal remains, many scavengers also function as predators. Ca... more Abstract In addition to feeding on animal remains, many scavengers also function as predators. Carcasses may therefore affect local animal communities by attracting facultative scavengers and increasing predation risk for other species in the vicinity of the carcasses. This risk may be elevated in low productivity environments, especially where humans increase carcass production and where facultative scavengers include invasive species. In June and October 2018, we monitored experimentally placed red kangaroo (Osphranter rufus) carcasses and artificial bird nests in two different habitats in the Simpson Desert, Australia, to identify the nest predators attracted to the carcasses, and to determine how carcasses affect overall and predator-specific nest predation. We modelled our nests to approximate those of the ground nesting little buttonquail (Turnix velox) and the endangered night parrot (Pezoporus occidentalis). Native Corvus spp. and then invasive red foxes (Vulpes vulpes) were the top carcass visitors and nest egg predators. Carcass presence and open habitat increased overall nest predation and fewer artificial parrot nest eggs were depredated compared to those of quail. Open habitat and carcass presence only increased predator-specific nest predation by foxes, but corvid nest predation was highest in June 2018, and for the artificial quail nest types. Foxes were the main predator of eggs from night parrot nests. Our study shows that carcass provisioning by humans may have indirect, deleterious effects on ground nesting birds, and indicates that foxes might pose a greater threat to night parrot populations than previously recognised.
Public opposition has shaped management of wild animals in Australia, but public interest in ding... more Public opposition has shaped management of wild animals in Australia, but public interest in dingo control has been minimal. We hypothesised that this is due to lack of awareness of dingo management practices, in part because using the term “wild dogs” to describe management renders “dingoes” invisible, framing the issue as one of control of introduced pests rather than control of an iconic Australian animal. We distributed an online questionnaire survey to the Australian public (N = 811) to measure how the public perceived dingoes and their management, how these views compared with other animals managed as pests in Australia, and whether the term “wild dogs” has shaped views and knowledge of dingo management. Most respondents (84.6%) considered dingoes to be native to Australia and there was low approval of lethal control methods, except when justification was provided (e.g., to protect livestock or endangered native species). Only 19.1% were aware that “wild dog” management includ...
Livestock producers and governments have managed predators to protect livestock for millennia. Bu... more Livestock producers and governments have managed predators to protect livestock for millennia. But in recent decades attitudes towards predators and their management have shifted from solely killing towards coexistence and even conservation. In Australia, a continent-wide survey of graziers conducted in the 1950s provides an opportunity to consider how attitudes and practices surrounding dingo management have changed over the last 60 years. We created a survey that repeated questions and themes from the 1950s study and sent this to 75 of the properties where the original survey had been completed. We received 23 complete or semicomplete responses. Ground-baiting and shooting continue to form a major focus of management on the focal properties, while fewer respondents used trapping and fencing in the current survey than in the 1950s. Ten properties had adopted either or both of two lethal methods (aerial baiting and hiring professional doggers) since the 1950s survey. Unlike the 1950...
Studies of environmental history provide an important lens through which to analyse our contempor... more 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 re...
Carnivore predation on livestock often leads people to retaliate. Persecution by humans has contr... more Carnivore predation on livestock often leads people to retaliate. Persecution by humans has contributed strongly to global endangerment of carnivores. Preventing livestock losses would help to achieve three goals common to many human societies: preserve nature, protect animal welfare, and safeguard human livelihoods. Between 2016 and 2018, four independent reviews evaluated >40 years of research on lethal and nonlethal interventions for reducing predation on livestock. From 114 studies, we find a striking conclusion: scarce quantitative comparisons of interventions and scarce comparisons against experimental controls preclude strong inference about the effectiveness of methods. For wise investment of public resources in protecting livestock and carnivores, evidence of effectiveness should be a prerequisite to policy making or large-scale funding of any method or, at a minimum, should be measured during implementation. An appropriate evidence base is needed, and we recommend a coa...
ABSTRACT Australia has a range of native and introduced large herbivores that could affect the ab... more ABSTRACT Australia has a range of native and introduced large herbivores that could affect the abundance of small mammals through direct and indirect effects. Here we study the relationship between occurrence of the introduced rusa deer (Rusa timorensis) and the native swamp wallaby (Wallabia bicolor), and the abundance of four species of native small mammals in coastal heath vegetation with varying fire history.The abundance of two species, the brown antechinus (Antechinus stuartii) and bush rat (Rattus fuscipes), was related to occurrence of large herbivores and was dependent also on fire history. Abundance of swamp rats (R. lutreolus) and New Holland mice (Pseudomys novaehollandiae) was not related to the occurrence of any of the large herbivores, and did not depend on fire history. At sites burned within the last 9 years, captures of brown antechinus were negatively related to both deer and wallaby occurrence, and captures of bush rats were negatively related to deer occurrence. However, at sites that burned more than 15 years ago, captures of brown antechinus and bush rats were not related to large herbivore occurrence. Overall there was either no relationship, or a negative one, between small mammals and the large herbivores.This mensurative study has demonstrated relationships between deer and wallabies and small mammals, with fire as an additional important factor. From the results of the current study we put forward a series of hypotheses that need to be tested by future experiments.
Choosing the appropriate method to detect and monitor wildlife species is difficult if the specie... more Choosing the appropriate method to detect and monitor wildlife species is difficult if the species is rare or cryptic in appearance or behaviour. We evaluated the effectiveness of the following four methods for detecting red foxes (Vulpes vulpes) on the basis of equivalent person hours in a rural landscape in temperate Australia: camera traps, hair traps (using morphology and DNA from hair follicles), scats from bait stations (using DNA derived from the scats) and spotlighting. We also evaluated whether individual foxes could be identified using remote collection of their tissues. Genetic analysis of hair samples was the least efficient method of detection among the methods employed because of the paucity of samples obtained and the lack of follicles on sampled hairs. Scat detection was somewhat more efficient. Scats were deposited at 17% of bait stations and 80% of scats were amplified with a fox-specific marker, although only 31% of confirmed fox scats could be fully genotyped at ...
Proceedings of the Royal Society B: Biological Sciences, 2009
Alien predators can have catastrophic effects on ecosystems and are thought to be much more harmf... more Alien predators can have catastrophic effects on ecosystems and are thought to be much more harmful to biodiversity than their native counterparts. However, trophic cascade theory and the mesopredator release hypothesis predict that the removal of top predators will result in the reorganization of trophic webs and loss of biodiversity. Using field data collected throughout arid Australia, we provide evidence that removal of an alien top-predator, the dingo, has cascading effects through lower trophic levels. Dingo removal was linked to increased activity of herbivores and an invasive mesopredator, the red fox ( Vulpes vulpes ), and to the loss of grass cover and native species of small mammals. Using species distribution data, we predict that reintroducing or maintaining dingo populations would produce a net benefit for the conservation of threatened native mammals across greater than 2.42 × 10 6 km 2 of Australia. Our study provides evidence that an alien top predator can assume a ...
Mating in the marsupial genus Antechinus is a synchronous annual event that is characterized by m... more Mating in the marsupial genus Antechinus is a synchronous annual event that is characterized by monoestry in females and abrupt postmating mortality in males. Male semelparity (multiple copulations during a single breeding season per lifetime) is often assumed to occur as a consequence of the intense mating effort expended by males in the rut, but the forces selecting for this remain elusive. Here, we investigate selection in male brown antechinus, Antechinus stuartii, and test two hypotheses for the evolution of semelparity: intermale competition and sperm competition. If intermale competition drives semelparity, we predicted that males would be under strong selection for large body size. If sperm competition is important, we predicted that selection would be strongest on scrotal size, a surrogate for testes volume. Using microsatellite markers, we found that 92% of females in free‐living conditions mated with multiple males, producing litters of eight that had up to four fathers. ...
Aim To determine whether latitudinal and longitudinal gradients in seed mass are related to vari... more Aim To determine whether latitudinal and longitudinal gradients in seed mass are related to variation in climatic features including temperature, solar radiation and rainfall.Location Australia.Methods Seed mass was estimated from over 1600 provenances covering the latitudinal and longitudinal extents of 34 perennial Glycine taxa in Australia. Climatic data were obtained from ANUCLIM 5.1 for collection locations based on long‐term meteorological records across Australia. These climatic data were subject to principal components analysis to extract three components as climatic indices. Generalized linear models were used in three separate sets of analyses to evaluate whether seed mass–latitude and seed mass–longitude relationships persisted after taking climatic variation into account. First, relationships were examined across species in analyses that did not explicitly consider phylogenetic relationships. Secondly, phylogenetic regressions were performed to examine patterns of cor...
The introduction of invasive alien predators often has catastrophic effects on populations of naï... more The introduction of invasive alien predators often has catastrophic effects on populations of naïve native prey, but in situations where prey survive the initial impact a predator may act as a strong selective agent for prey that can discriminate and avoid it. Using two common species of Australian small mammals that have persisted in the presence of an alien predator, the European red fox Vulpes vulpes, for over a century, we hypothesised that populations of both would perform better where the activity of the predator was low than where it was high and that prey individuals would avoid signs of the predator's presence. We found no difference in prey abundance in sites with high and low fox activity, but survival of one species-the bush rat Rattus fuscipes-was almost twofold higher where fox activity was low. Juvenile, but not adult rats, avoided fox odour on traps, as did individuals of the second prey species, the brown antechinus, Antechinus stuartii. Both species also showe...
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