Diet of dingoes and other wild dogs in peri-urban areas of north-eastern Australia

Anthropogenic and environmental factors associated with koala deaths due to dog attacks and vehicle collisions in South-East Queensland, Australia, 2009-2013

Populations of the iconic Australian koala are under constant decline. Their deaths are associated with rapid and extensive urbanization and the fragmentation of habitat areas. Using citizen science data on reported koala mortalities, we quantified the association between anthropogenic and environmental factors and the two leading causes of koala deaths, dog attacks and vehicle collisions. We achieved this objective using a case-control study design to compare the odds of exposure to a given risk factor for cases (a given cause of death) with the odds of exposure to a given risk factor for controls (all other causes of death). Koala deaths due to dog attacks were positively associated with registered dog population density and negatively associated with lot density whereas koala deaths due to vehicle collisions were positively associated with road density (road length per square kilometer) and negatively associated with human population density and distance to primary and secondary roads. The results of this research can be used to develop strategies to mitigate the risk of deaths due to dog attacks, for example by conducting educational awareness programs, promoting registration of dogs and discouraging free roaming of dogs. In a similar manner, in high-risk areas for vehicle collisions, over- or underpasses can be built to facilitate safe movement of koalas for road crossings or speed limits could be introduced to reduce the likelihood of premature koala deaths due to vehicle collisions.

Diet of the Dingo in Subtropical Australian Forests: Are Small, Threatened Macropods at Risk?

Carnivores fulfil important ecological roles in natural systems yet can also jeopardise the persistence of threatened species. Understanding their diet is, therefore, essential for managing populations of carnivores, as well as those of their prey. This study was designed to better understand the diet of an Australian apex predator, the dingo, and determine whether it poses a threat to at-risk small macropods in two floristically different yet geographically close reserves in subtropical Australia. Based on an analysis of 512 scats, dingo diets comprised 34 different prey taxa, of which 50% were common between reserves. Our findings add support to the paradigm that dingoes are opportunistic and generalist predators that prey primarily on abundant mammalian fauna. Their diets in the Border Ranges were dominated by possum species (frequency of occurrence (FOC) = 92.5%), while their diets in Richmond Range were characterised by a high prevalence of pademelon species (FOC = 46.9%). Medium-sized mammals were the most important dietary items in both reserves and across all seasons. The dietary frequency of medium-sized mammals was generally related to their availability (indexed by camera trapping); however, the avoidance of some species with high availability indicates that prey accessibility may also be important in dictating their dietary choices. Other prey categories were supplementary to diets and varied in importance according to seasonal changes in their availability. The diets included two threatened macropods, the red-legged pademelon and black-striped wallaby. Our availability estimates, together with earlier dietary studies spanning 30 years, suggest that the red-legged pademelon is resilient to the observed predation. The black-striped wallaby occurred in only two dingo scats collected from Richmond Range and was not detected by cameras so the threat to this species could not be determined. Two locally abundant but highly threatened species (the koala and long-nosed potoroo) were not detected in the dingoes' diets, suggesting dingoes do not at present pose a threat to these populations. Our study highlights the importance of site-based assessments, population monitoring and including data on prey availability in dietary investigations.

Distinctive diets of eutherian predators in Australia

Introduction of the domestic cat and red fox has devastated Australian native fauna. We synthesized Australian diet analyses to identify traits of prey species in cat, fox and dingo diets, which prey were more frequent or distinctive to the diet of each predator, and quantified dietary overlap. Nearly half (45%) of all Australian terrestrial mammal, bird and reptile species occurred in the diets of one or more predators. Cat and dingo diets overlapped least (0.64 ± 0.27, n = 24 location/time points) and cat diet changed little over 55 years of study. Cats were more likely to have eaten birds, reptiles and small mammals than foxes or dingoes. Dingo diet remained constant over 53 years and constituted the largest mammal, bird and reptile prey species, including more macropods/potoroids, wombats, monotremes and bandicoots/bilbies than cats or foxes. Fox diet had greater overlap with both cats (0.79 ± 0.20, n = 37) and dingoes (0.73 ± 0.21, n = 42), fewer distinctive items (plant material, possums/gliders) and significant spatial and temporal heterogeneity over 69 years, suggesting the opportunity for prey switching (especially of mammal prey) to mitigate competition. Our study reinforced concerns about mesopredator impacts upon scarce/threatened species and the need to control foxes and cats for fauna conservation. However, extensive dietary overlap and opportunism, as well as low incidence of mesopredators in dingo diets, precluded resolution of the debate about possible dingo suppression of foxes and cats.

Before Azaria: A Historical Perspective on Dingo Attacks

This paper investigates the origin of the once popular belief in Australian society that wild dingoes do not attack humans. To address this problem, a digital repository of archived newspaper articles and other published texts written between 1788 and 1979 were searched for references to dingoes attacking non-Indigenous people. A total of 52 accounts spanning the period between 1804 and 1928 was identified. A comparison of these historical accounts with the details of modern dingo attacks suggests that at least some of the former are credible. The paper also examined commonly held attitudes towards dingoes in past Australian society based on historical print media articles and other records. Early chroniclers of Australian rural life and culture maintained that dingoes occasionally killed and ate humans out of a predatory motivation. By the early decades of the 20th century, however, an opposing view of this species had emerged: namely, that dingoes were timid animals that continued to pose a danger to livestock, but never to people. This change in the cultural image of dingoes can possibly be linked to more than a century of lethal dingo control efforts greatly reducing the frequency of human–dingo interactions in the most populous parts of the country. This intensive culling may also have expunged the wild genetic pool of dingoes that exhibited bold behaviour around people and/or created a dingo population that was largely wary of humans.

Predation and Scavenging in the City: A Review of Spatio-Temporal Trends in Research

Many researchers highlight the role of urban ecology in a rapidly urbanizing world. Despite the ecological and conservation implications relating to carnivores in cities, our general understanding of their potential role in urban food webs lacks synthesis. In this paper, we reviewed the scientific literature on urban carnivores with the aim of identifying major biases in this topic of research. In particular, we explored the number of articles dealing with predation and scavenging, and assessed the geographical distribution, biomes and habitats represented in the scientific literature, together with the richness of species reported and their traits. Our results confirmed that scavenging is largely overlooked compared to predation in urban carnivore research. Moreover, research was biased towards cities located in temperate biomes, while tropical regions were less well-represented, a pattern that was more evident in the case of articles on scavenging. The species reported in both predation and scavenging articles were mainly wild and domestic mammals with high meat-based diets and nocturnal habits, and the majority of the studies were conducted in the interior zone of cities compared to peri-urban areas. Understanding the trophic role of carnivores in urban environments and its ecological consequences will require full recognition of both their predation and scavenging facets, which is especially desirable given the urban sprawl that has been predicted in the coming decades.

A population of free-living highland wild dogs in Indonesian Papua

A 10-day rapid assessment has confirmed a small population of indigenous wild-living dogs in the highlands of Papua Province, Indonesia. The goal of the assessment was to observe, census, assess health and reproductive status, and collect biological samples or other data for this understudied canid. Trail cameras and DNA hair traps were deployed and baited with scent attractants, and game calls were used to elicit vocal responses or lure the dogs within observation range. Adults and pups of both sexes as well as a den were documented in 149 photographs. DNA testing of scat samples confirmed a canid origin with a close relationship to other oceanic canids including NGSD (New Guinea Singing Dog) and dingoes.

High rates of cannibalism and food waste consumption by dingoes living at a remote mining operation in the Great Sandy Desert, Western Australia

Mining operations in remote Australia represent a unique opportunity to examine the impact of supplementary food and water provision on local wildlife. Here, we present a dietary analysis of dingoes living at a mine site in the Great Sandy Desert, Western Australia. A total of 270 faeces (scats) were collected from across the mine footprint on two occasions three months apart. The most frequently consumed food resource was anthropogenic (rubbish), which was found in 218 of 270 faeces (80.7% of scats and 65.3% of scat volume). Also of note was a high proportion of dingo remains, which was found in 51 of 270 faeces (18.9% of scats and 10.4% of scat volume), suggesting the occurrence of cannibalism. These findings highlight the potential influence of human-modified areas and associated resource availability on the diet of dingoes, and have implications for the environmental management of areas surrounding mining operations.

Geographical distribution and risk factors for Echinococcus granulosus infection in peri-urban wild dog populations

The transmission of zoonotic pathogens associated with wildlife in peri-urban environments can be influenced by the interplay of numerous socioecological factors. Echinococcus granulosus is known to be common within peri-urban wild dog populations however knowledge of the factors that influence its presence is limited. We investigated the demographic distribution of adult cestode abundance (ACA: defined as the product between prevalence of infection and adult cestode infection intensity) and the role of the physical environment, climate and individual factors in determining the geographical variation of E. granulosus infection in wild dog populations from southeast Queensland and surrounds. Our results align with previous studies that show significant E. granulosus aggregation in that 15.8% of peri-urban wild dogs sampled were responsible for ∼70% of the total adult cestode infection intensity. On average, female dogs were found to have a higher ACA than male dogs, and the average ACA generally decreased with age. Significant geographical variation was found in the prevalence of E. granulosus, with a strong propensity for clustering. The average size of clusters was 22.5 km. The probability of finding E. granulosus infection significantly increased with maximum temperature, relative humidity, and rainfall, and after accounting for individual and climatic variables, the model accounted for the majority of the spatial dependence in prevalence. Our predictive map of E. granulosus prevalence in peri-urban wild dogs confirms that E. granulosus is highly endemic in the eastern Australia study area. The prediction map provides a useful tool for targeting potential disease management strategies in peri-urban areas, where broad scale management of wild dog populations is difficult to implement.

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E. granulosus is common in peri-urban wild dog populations.

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E. granulosus worm burdens in peri-urban wild dogs are highly aggregated.

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Bitches and pups have higher adult cestode infection intensity than males and older animals.

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High endemic regions of E. granulosus are present within human developed environs.

Flexible Use of Urban Resources by the Yellow Mongoose Cynictis penicillata

Several species are negatively impacted by urbanization, while others thrive in urban areas by exploiting anthropogenic habitats matching their pre-existing niche preferences, or by modifying their behavior for urban life. We studied the ecology of a recent urban resident, the yellow mongoose, in an urban ecological estate in South Africa. We assessed urban dwelling yellow mongooses' diet, spatial and temporal occurrence, home range size, and whenever possible, compared our findings to the published literature on their non-urban conspecifics. Additionally, we evaluated occurrence overlap with residential gardens. Similar to their non-urban counterparts, scat analyses revealed that yellow mongooses in urban areas fed mainly on insects, particularly during spring/summer. In the colder months, anthropogenic items, small mammals and birds in scats increased. Camera trap surveys showed that the mongooses were common in open habitats, similar to previous studies, and exhibited a species-typical bimodal diurnal activity pattern. The occurrence of these mongooses was greater near human residences than at sites further away. Home range sizes were considerably smaller than those of non-urban mongoose. Mongoose occurred in residential gardens, more so during the colder months. The urban yellow mongooses' diet, habitat preference and activity patterns were similar to non-urban conspecifics. Nonetheless, the exploitation of anthropogenic food sources, occurrence in residential gardens and smaller home range sizes showed that they respond flexibly to urbanization, and these modifications might aid in their success in urban areas.

Dietary overlap of two sympatric African mongoose species in an urban environment

Urbanisation creates challenges and opportunities for wildlife. Globally, small carnivores have colonised urban spaces, but we do not know whether or how sympatric carnivores partition resources in order to co-exist. We studied the diet and degree of dietary overlap of two sympatric herpestid mongooses – yellow, Cynictis penicillata, and slender, Galerella sanguinea mongoose – in a small urban nature area in South Africa. The composition of 2600 yellow and 2000 slender mongoose scats was sampled over a year in an Eco-Estate, where wildlife have contact with humans, and a Nature Estate, where contact is reduced. We analysed the frequency of occurrence of invertebrates, mammals, birds, plants and anthropogenic items in scats. Invertebrates and mammals were most abundant for both species in the Nature Estate and for slender mongoose in the Eco-Estate, while anthropogenic items were more prevalent in yellow mongoose scats in the Eco-Estate. Both species included anthropogenic items in their diet in the Eco-Estate only. Scat components varied seasonally. In summer, invertebrates were more abundant in scats of both species, yet during the colder months, invertebrates decreased and vertebrates (more so in the slender mongoose) and anthropogenic items (more so in the yellow mongoose) increased. Dietary overlap was greatest in summer and lowest in winter. Nonetheless, the specialised slender mongoose diet and a generalist yellow mongoose diet potentially facilitates their co-existence.

The association between diet of periurban wild dogs and zoonotic pathogen carriage

Established wildlife populations in periurban environments provide an opportunity to spread zoonotic pathogens within human-associated environments. Characteristics of prevalent pathogens harboured by periurban wild dogs suggest that dietary preference could influence their infection status; however, data comparing diet composition and pathogen presence are rarely available. We analysed the stomach contents of 170 periurban wild dogs (Canis familiaris) for the occurrence and biomass of prey items, and then associated this with their known infection status of key zoonotic pathogens. The staple prey items detected were mammalian prey species, most commonly swamp wallabies (Wallabia bicolor) (20.6±6.1%), canines (C. familiaris) (prey) (10.6±4.6%), eastern grey kangaroos (Macropus giganteus) (10.0±4.5%), and deer (various species) (10.0±4.5%). Unidentified bird species (10.0±4.5%) were also common. Wild dogs that were positive for Echinococcus granulosus were significantly more likely to have consumed swamp wallabies. These findings demonstrate the importance of managing both the definitive and intermediate stages of E. granulosus, and suggest that diet correlates with pathogen presence in some cases. This information may assist the development of specific strategies to manage zoonotic pathogens of wild dogs, which are currently lacking.

Zoonotic and economically significant pathogens of peri-urban wild dogs across north-eastern New South Wales and south-eastern Queensland, Australia

Context Peri-urban wild dogs are known to reside within high-risk and densely populated regions and are capable of harbouring a variety of zoonotic pathogens. Despite recognising the potential of peri-urban wild dogs to carry zoonotic pathogens, limited prevalence data are currently available to assist in understanding the potential risks that peri-urban wild dogs pose within developed communities. Aims The aim of the present research was to establish the current status of key zoonotic and economically significant pathogens in peri-urban wild dogs. Methods Two hundred and one peri-urban wild dog cadavers were collected from south-eastern Queensland and northern New South Wales. In addition, whole blood, serum and faecal samples were also collected. Pathogens were identified through several morphological, microbiological and molecular methods. Key results Helminth parasites were detected within 79.6% of peri-urban wild dogs; Echinococcus granulosus was the most common pathogen, with adult worms being detected within 50.7 ± 6.9% of intestines, followed by Spirometra erinacei (36.6 ± 6.4%); hookworms, including Ancylostoma caninum and Uncinaria stenocephala (28.8 ± 7.1%); Toxocara canis (5.4 ± 3.1%) and Taenia spp., including T. serialis and T. pisiformis (4.5 ± 2.8%). Bacterial pathogens detected included methicillin-resistant Escherichia coli (20.0 ± 10.1%), Salmonella spp. (3.7 ± 4.0%) and methicillin-sensitive Staphylococcus aureus (3.3 ± 2.7%). Conclusions The present study is the most comprehensive investigation of zoonotic pathogen carriage in peri-urban wild dogs in Australia. Parasitic infections in peri-urban wild dogs are common, with tapeworms representing the majority of intestinal pathogens. Important zoonotic bacterial pathogens are carried by peri-urban wild dogs, although at a much lower prevalence than are parasites. Implications The presence of these pathogens in free-ranging peri-urban dog populations suggests a strong potential for public health risk, most notably from E. granulosus. These data are inherently important as baseline information, which is essential to guide risk-based management of peri-urban wild dog impacts.

Utilisation of stranded marine fauna washed ashore on K’gari (Fraser Island), Australia, by dingoes

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.

Prey use by dingoes in a contested landscape: Ecosystem service provider or biodiversity threat?

In Australia, dingoes (Canis lupus dingo) have been implicated in the decline and extinction of a number of vertebrate species. The lowland Wet Tropics of Queensland, Australia is a biologically rich area with many species of rainforest-restricted vertebrates that could be threatened by dingoes; however, the ecological impacts of dingoes in this region are poorly understood. We determined the potential threat posed by dingoes to native vertebrates in the lowland Wet Tropics using dingo scat/stomach content and stable isotope analyses of hair from dingoes and potential prey species. Common mammals dominated dingo diets. We found no evidence of predation on threatened taxa or rainforest specialists within our study areas. The most significant prey species were northern brown bandicoots (Isoodon macrourus), canefield rats (Rattus sordidus), and agile wallabies (Macropus agilis). All are common species associated with relatively open grass/woodland habitats. Stable isotope analysis suggested that prey species sourced their nutrients primarily from open habitats and that prey choice, as identified by scat/stomach analysis alone, was a poor indicator of primary foraging habitats. In general, we find that prey use by dingoes in the lowland Wet Tropics does not pose a major threat to native and/or threatened fauna, including rainforest specialists. In fact, our results suggest that dingo predation on "pest" species may represent an important ecological service that outweighs potential biodiversity threats. A more targeted approach to managing wild canids is needed if the ecosystem services they provide in these contested landscapes are to be maintained, while simultaneously avoiding negative conservation or economic impacts.

The denning behaviour of dingoes (Canis dingo) living in a human-modified environment

Little is known about reproduction and den site selection by free-ranging dingoes. We present observations of den sites used by dingoes inhabiting a large-scale mining operation located in the Great Sandy Desert, Western Australia. We observed 24 dens concentrated within a 1-km radius. Den sites were generally situated in elevated positions overlooking the surrounding area, were a short distance from food and water resources, required vegetation (particularly spinifex grass) to provide a firm foundation and stable ceiling in the soft sand, and had single den openings that faced away from the rising and daytime sun. Distance to human structures or activity did not appear to influence site selection. Four of the dens were active, containing a total of 37 pups aged between two and four weeks of age. One den contained 18 pups of different ages, indicating that communal denning was also occurring. The high number of breeding females within close proximity suggests that multiple family groups are able to share resources and live in close proximity. Our findings highlight the importance of human-modified areas and abundance of resources in the reproduction and breeding site selection of dingoes.

Dingoes at the Doorstep: Home Range Sizes and Activity Patterns of Dingoes and Other Wild Dogs around Urban Areas of North-Eastern Australia

Simple summary

Conflicts with dingoes and other wild dogs are becoming increasingly common in and around urban areas of Australia. A lack of basic information about wild dog movement ecology hampers efficient planning and allocation of resources to mitigate human–wild dog conflicts. We captured, collared and released 37 wild dogs in urban areas of north-eastern Australia to investigate their movement ecology. In general, wild dogs occupied small fragments of bushland within an urban matrix, were active at all times of the day, and lived within a few hundred meters of houses and humans at all times. We conclude that wild dog management strategies in urban areas should focus on the mitigation of impacts at the individual or group level, and not population-level reductions in numbers.

Abstract

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 × domestic dog hybrids are common in many urban areas, and pose a variety of human health and safety risks. However, data on urban dingo ecology is scant. We GPS-collared 37 dingoes in north-eastern Australia and continuously monitored them each 30 min for 11–394 days. Most dingoes 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.