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Interactions between a Top Order Predator and Exotic Mesopredators in the Australian Rangelands
Abstract and Figures
An increase in mesopredators caused by the removal of top-order predators can have significant implications for threatened wildlife. Recent evidence suggests that Australia’s top-order predator, the dingo, may suppress the introduced cat and red fox. We tested this relationship by reintroducing 7 foxes and 6 feral cats into a 37 km
2
fenced paddock in arid South Australia inhabited by a male and female dingo. GPS datalogger collars recorded locations of all experimental animals every 2 hours. Interactions between species, mortality rates, and postmortems were used to determine the mechanisms of any suppression. Dingoes killed all 7 foxes within 17 days of their introduction and no pre-death interactions were recorded. All 6 feral cats died between 20 and 103 days after release and dingoes were implicated in the deaths of at least 3 cats. Dingoes typically stayed with fox and cat carcasses for several hours after death and/or returned several times in ensuing days. There was no evidence of intraguild predation, interference competition was the dominant mechanism of suppression. Our results support anecdotal evidence that dingoes may suppress exotic mesopredators, particularly foxes. We outline further research required to determine if this suppression translates into a net benefit for threatened prey species.
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... Aligning or joining our review to this earlier one required slight adjustment to our reported sample sizes (numbers of studies) to avoid re-reviewing or double-counting studies already reviewed (e.g. Moseby et al., 2012), or to accommodate the conversion of grey literature reports completed and reviewed prior to 2012 later being published after 2012 (e.g. compare Allen, 2005or Eldridge et al., 2002with Allen et al., 2013a; see also Edwards et al., 2021). ...
... collected over larger spatiotemporal scales provides more information on population-level relationships between predators than a smaller amount of data collected over smaller spatiotemporal scales, especially when greater amounts of data are collected within an inferentially strong experimental design . We concur with Moseby et al. (2012) that studies reliant on scales and sample sizes at the smaller end of these spectrums are unable to yield reliable inferences about dingo-mesopredator relationships at population-level scales relevant to predator managers and policy makers. As valuable as large amounts of data collected over large spatiotemporal scales are (as did Arthur et al., 2013), even they cannot be reliably used to make causal inferences when they are derived from correlations. ...
... The ecological roles of dingoes are also debated, particularly with regard to their ability to suppress abundant herbivores, including kangaroos (specifically Osphranter and Macropus species), emus (Dromaius novaehollandiae), feral goats (Capra hircus), European rabbits (Oryctolagus cuniculus), feral pigs (Sus scrofa), and smaller predators including feral cats (Felis catus) and European red foxes (Vulpes vulpes) Emmott, 2021;Fancourt et al., 2019;Fleming et al., 2013;Letnic et al., , 2012Moseby et al., 2012;Ritchie et al., 2012). These proposed ecological functions potentially provide conservation benefits for threatened species Hayward & Marlow, 2014;Letnic & Dworjanyn, 2011;Morrant et al., 2017;Nimmo et al., 2015;Wallach et al., 2009) and in some cases livestock production (Allen & Gonzalez, 1998;Emmott, 2021;Forsyth et al., 2014;Prowse et al., 2015). ...
... Contested evidence on how dingoes affect local wildlife populations, including native and nonnative species, and livestock production Wallach et al., 2009;Letnic & Dworjanyn, 2011;Johnson & Ritchie, 2012;Letnic et al., , 2012Moseby et al., 2012;Ritchie et al., 2012;Allen, Fleming, et al., 2013;Fleming et al., 2013;Hayward & Marlow, 2014;Nimmo et al., 2015;Morrant et al., 2017;Fancourt et al., 2019;Allen et al., 2021;Castle et al., 2021;Emmott, 2021;Kreplins et al., 2021 Management practices ...
Expert elicitation can be valuable for informing decision-makers on conservation and wildlife management issues. To date, studies eliciting expert opinions have primarily focused on identifying and building consensus on key issues. Nonetheless , there are drawbacks of a strict focus on consensus, and it is important to understand and emphasize dissent, too. This study adopts a dissensus-based Del-phi to understand conflict among dingo experts. Twenty-eight experts participated in three rounds of investigation. We highlight disagreement on most of the issues explored. In particular, we find that disagreement is underpinned by what we call "conflict over values" and "conflict over evidence." We also note the broader role played by distrust in influencing such conflicts. Understanding and recognizing the different elements shaping disagreement is critical for informing and improving decision-making and can also enable critique of dominant paradigms in current practices. We encourage greater reflexivity and open deliberation on these aspects and hope our study will inform similar investigations in other contexts.
... In an experiment where artificial night parrot nests were created in spinifex hummocks in the Simpson Desert, foxes were the main predator to remove eggs from nests within spinifex (Spencer et al. 2021). Although fox is not commonly recorded in dingo diet, dingoes are known to kill foxes and not eat them (Moseby et al. 2012) and it is likely that foxes avoid areas with a heavy dingo presence. Thus, even though we cannot prove that dingoes play a key role in the ecosystem night parrots inhabit at Ngururrpa, we suggest that any actions that might disrupt dingo populations could be risky and should be avoided. ...
Context
The Endangered night parrot (Pezoporus occidentalis) is one of the rarest birds in Australia, with fewer than 20 known to occur in Queensland and, prior to 2020, only occasional detections from a handful of sites in Western Australia (WA). Here, we provide an introduction to night parrots on the Ngururrpa Indigenous Protected Area (IPA) in WA from the perspectives of both Indigenous rangers and scientists working together to understand their ecology.
Aims
We aimed to identify night parrot sites on the Ngururrpa IPA, compare habitat and likely threats with those in Queensland and identify appropriate management practices.
Methods
Between 2020 and 2023, we used songmeters (a type of acoustic recorder) to survey for the presence of night parrots at 31 sites (>2 km apart). At sites where parrots were detected, we used camera-traps to survey predators and collected predator scats for dietary analysis. Forty years of Landsat images were examined to assess the threat of fire to roosting habitat.
Key results
Night parrots were detected at 17 of the 31 sites surveyed on the Ngururrpa IPA. Positive detections were within an area that spanned 160 km from north to south and 90 km from east to west. Ten roosting areas were identified, and these occurred in habitat supporting the same species of spinifex (lanu lanu or bull spinifex, Triodia longiceps) used for roosting in Queensland. However, the surrounding landscapes differ in their vegetation types and inherent flammability, indicating that fire is likely to be a more significant threat to night parrots in the Great Sandy Desert than in Queensland. Dingoes (Canis dingo) were the predator species detected most frequently in night parrot roosting habitat and the feral cat was found to be a staple prey for dingoes at night parrot sites.
Conclusions
Our surveys indicated that there could be at least 50 night parrots on the Ngururrpa IPA, which is the largest known population in the world. Fire is a key threat to roosting habitat, occurring in the surrounding sandplain country every 6–10 years. Dingoes are common in night parrot habitat and regularly eat feral cats, which are only occasionally detected in roosting habitat.
Implications
We recommend management that focuses on strategic burning to reduce fuel loads in the surrounding landscape, and limiting predator control to methods that do not harm dingoes.
... The reserve is divided into six paddocks, with cats, foxes, and rabbits (Oryctolagus cuniculus) removed from four of these, totalling 60 km 2 , whereas the remaining two paddocks 'Red Lake' (25 km 2 ) and the 'Experimental Paddock' (37 km 2 ) contain populations of feral cats and rabbits and are used for landscapescale manipulation experiments (e.g. Moseby et al. 2012;West et al. 2018;Ross et al. 2019;McGregor et al. 2020a). ...
Context
Animal-borne devices can affect animal survival, reproduction, and behaviour through both the addition of weight and bulk and the direct effects of initial and subsequent capture. Researchers commonly employ a general rule of thumb that weight of the device must be less than 5% of bodyweight for terrestrial animals; however, this threshold has little empirical basis.
Aims
We evaluated the effects of environmental variables, repeated capture, and weight of animal-borne devices on bodyweight in free-ranging feral cats.
Methods
We recaptured feral cats at varying frequencies, wearing GPS and/or VHF collars that ranged from 0.29% to 4.88% of bodyweight, and recorded change in cat weight over time.
Key results
Collar weight as a percentage of bodyweight was not a significant predictor of feral cat weight change. Rather, change in bodyweight was best described by a negative relationship with an increasing temperature and number of captures, and a positive relationship with time since collar attachment.
Conclusions
Capture had a significant influence on feral cat weight but collar weights up to 5% of bodyweight did not significantly contribute to weight loss. However, the absence of control cats without collars hindered definitive conclusions on the effect of collar weight on cat weight change.
Implications
Researchers should space capture and handling events more than 30 days apart to reduce effects of weight loss from capture and handling. Researchers should also consider increasing collar weight and reducing frequency of capture (where collars are less than 5% of bodyweight), particularly if cat bodyweight is a parameter of interest.
... For example, a key facet of an apex predator is that it induces trophic cascades. 1 Dingoes can and do cause trophic cascades by suppressing the abundance of prey and/or mesopredators (either through direct predation or landscapes of fear) and thus indirectly benefitting vegetation and the prey of mesopredators, respectively (Letnic et al 2009;Moseby et al 2012). Several studies indicate that dingoes strongly suppress herbivores weighing 7-100kg and introduced mesopredators in some locations (but see Fancourt et al 2019), and can have beneficial effects on populations of small mammals and ground-nesting birds due to release from predation by mesopredators and vegetation suppression by herbivores (eg Letnic et al 2009;Letnic et al 2012;Gordon et al 2017). ...
THE DINGO: IDENTITY, ORIGIN AND CONTROVERSY
The continent of Australia is home to the dingo (Canis dingo Meyer, 1793), a free-ranging member of the genus Canis. Affectionately known as the ‘king of the Australian bush’, the dingo is the largest extant mammalian predator (other than humans) in Australia. Yet, at an average of 16kg (range 10–25kg) and standing approximately 55cm to the shoulder, they are relatively small for an apex predator. The quintessential dingo is lean with short fur, has erect ears atop a broad head, fluffy tail and is often yellow or ginger in colour with white points on its toes, feet and tail (Smith 2015). However, coat colours and white patches of pure dingoes vary considerably, including sandy white/cream, black and tan, and everything in between (Fig 15.1; Cairns et al 2021a). The dingo is a highly adaptable and resilient predator. It is: present across the entire mainland and occupies all habitat types of Australia; lives in strict social hierarchies and exhibits complex communication; is highly territorial, with a home range that varies greatly depending on the region; and is a generalist and opportunistic hunter that kills and eats a variety of prey, including species much larger than itself (eg kangaroos, Macropus spp.). Due to the threat it may pose to livestock (Fleming et al 2001), the dingo is considered a pest species across much of its range and remains unprotected in many regions and jurisdictions of Australia. Historical and ongoing persecution by humans, primarily in urban and agricultural areas, remains the dingo's biggest threat, and is likely a leading cause of hybridisation events with domestic dogs (Cairns et al 2021b).
The dingo is a naturalised Australian species. The oldest archeological dingo remains have been carbon-dated to be between 3000 and 3500 years old (Balme et al 2018), setting this as a minimum time the species has been present in Australia. Molecular dating efforts indicate that the dingo has been genetically distinct from both dogs and wolves for at least 8000–11,000 years (Cairns and Wilton 2016; Bergstrom et al 2020; Zhang et al 2020). This timing firmly places dingoes as having evolved pre-agriculture and prior to the diversification of other dogs into domestic breeds via intensive artificial selection.
... For example, a key facet of an apex predator is that it induces trophic cascades. 1 Dingoes can and do cause trophic cascades by suppressing the abundance of prey and/or mesopredators (either through direct predation or landscapes of fear) and thus indirectly benefitting vegetation and the prey of mesopredators, respectively (Letnic et al 2009;Moseby et al 2012). Several studies indicate that dingoes strongly suppress herbivores weighing 7-100kg and introduced mesopredators in some locations (but see Fancourt et al 2019), and can have beneficial effects on populations of small mammals and ground-nesting birds due to release from predation by mesopredators and vegetation suppression by herbivores (eg Letnic et al 2009;Letnic et al 2012;Gordon et al 2017). ...
... The region also contains two canid predators; the dingo (Canis dingo: 12 − 20 kg) and the recently introduced red fox (Vulpes vulpes; 3-14 kg). The foraging behaviours and interactions between these predators are of great ecological and economic significance due to their heavily debated impacts on vulnerable native mammal populations and farming practices (Moseby et al. 2012;Cooke and Soriguer 2017). The dingo is Australia's largest terrestrial predator and has coexisted with extant native prey species since its arrival on the continent ~ 5000 years ago (Fleming et al. 2001;Savolainen et al. 2004). ...
Unprecedented anthropogenic changes to biodiversity and biogeography demand a greater understanding of the consequences of altered faunal composition for ecosystem functioning. Selective predation has important, yet poorly understood effects on ecosystem stability, and can be strongly influenced by the relative frequencies of different prey types in the environment. Yet, how predators adjust their selection for prey according to their environmental frequency is often overlooked. Here, we assessed frequency dependent selection of prey by dingoes and foxes in the Australian desert, biannually, across a nine-year period (2007–2016). Both predators exhibited potentially destabilizing, negative frequency dependent selection for prey. Foxes persisted to preferentially consume a threatened, native rodent (Notomys fuscus) when it was environmentally scarce. Bolstered by the observation that N.fuscus occurs at low densities in areas where foxes are common, our results suggest that N.fuscus is particularly vulnerable to predation by this predator; possibly because it is naïve and/or lacks adaptations to avoid or escape predation by the relatively recently introduced fox. Dingoes tended to consume reptiles when they were scarce; potentially constituting a conservation concern if selected reptilian taxa are threatened. Foxes avoided, thus were unlikely to control populations of overabundant kangaroos, while both foxes and dingoes showed a preference for, and may therefore control populations of invasive rabbits. The integration of our results into the relative suites of (de)stabilizing influences exerted by dingoes and foxes is important to provide a more dynamic insight into how each predator impacts their naturally fluctuating ecosystems.
... The tracks in the sand from Arid Recovery show the race a fox made for its life while being chased by a dingo during an experimental translocation to study the interactions between these species (Moseby et al., 2012). Clearly, this interaction would have been highly stressful for the fox throughout the chase, until the dingo ultimately killed it. ...
The 'Compassionate Conservation' movement is gaining momentum through its promotion of 'ethical' conservation practices based on self-proclaimed principles of 'first-do-no-harm' and 'individuals matter'. We argue that the tenets of 'Compassionate Conservation' are ideological-that is, they are not scientifically proven to improve conservation outcomes, yet are critical of the current methods that do. In this paper we envision a future with 'Compassionate Conservation' and predict how this might affect global biodiversity conservation. Taken
Neophobia is an ecologically relevant personality trait that manifests as aversion to new or unfamiliar stimuli. Fear and subsequent avoidance of novel stimuli represents a challenge for pest management programs, as control tools that induce a neophobic response will reduce their effectiveness. Additionally, neophobia can be a plastic trait induced by exposure to high‐risk environments, and so can be exacerbated by repeated harassment, which often occurs in pest management programs that are conducted at high intensity. We investigated the propensity of feral cats (Felis catus) to exhibit neophobic behavior towards a novel control device. We also tested whether neophobia was altered by capture and radio‐collaring or changed over time. We found that there is significant potential for initial avoidance of control devices by some feral cats, and that capture and handling significantly increased the likelihood of avoidance. Neophobia generally declined over time suggesting that long‐term deployment may reduce the impact of neophobia. Avoidance of novel control tools could severely limit their effectiveness, especially if deployed to remove the last remaining cats from confined areas. Remaining cats may have avoided repeated attempts at conventional control techniques and so may be more neophobic. In such circumstances, control tool deployments should be lengthened considerably, to take advantage of waning neophobia over time, and, concealed effectively to hide them from neophobic cats. The increased neophobia recorded in cats that were handled and radio‐collared for monitoring suggests that results from experiments that test new control devices may not be indicative of the behavior of naïve cats. Changes to methodology such as minimizing capture and handling may be required to reduce neophobia and provide valid research results when testing novel control tools.
The role of the Dingo (variously Canis familiaris, C. familiaris dingo or C. lupus dingo, and hereafter C. dingo) in suppressing Red Fox (Vulpes vulpes) populations in Australia has been investigated, with various data tending to show an inverse relationship between densities of the two species (e.g. Letnic et al. 2012; Johnson and VanDerWal 2009). There are very few examples in the literature where direct killing was either observed or inferred (but see Moseby et al. 2012), making each a valuable datapoint. Here, we present a short description of a young adult female Red Fox presumed to have been killed by Dingo in Myall Lakes National Park on the basis of: (1) the close proximity of a Dingo pack (within approximately 20m) to the carcass; (2) the overlap between recorded values of inter-canine distance in Dingo and the wounds on the Red Fox; and (3) the location of those wounds on the body.
Felis catus, the domestic cat, occurs throughout the Australian mainland as well as on more than 40 islands off the Australian coast. Cats exploit diverse habitats, including deserts, forests, woodlands, grasslands, towns and cities, and occur from sea level to altitudes above 2000 m. The classification of cats as domestic, stray or feral (Moodie 1995) reflects the varied ecology of cats and their dichotomous status in Australia — as both a valued pet species and an introduced feral predator.
Impacts
Feral cats are carnivorous hunters that depredate animals up to 2 kg, but more often take prey under 200 g. The feral cat is linked to the early continental extinctions of up to seven species of mammals. They are also linked to island and regional extinctions of native mammals and birds and have caused the failure of reintroduction attempts aimed at re-establishing threatened species. Today, 35 vulnerable and endangered bird species, 36 mammal species, seven reptile species and three amphibian species are thought to be adversely affected by feral cats. Other species are potentially affected by infectious diseases transmitted by cats. The true environmental and economic impact of feral cats has not been calculated.
Legislation
In most Australian states and territories, legislation has been introduced to restrict the reproductive and predation potential of owned domestic cats. Many local government areas have introduced cat-specific legislation, with restrictions including the banning of cats as pets in some communities, compulsory neutering, individual identification, and containment of pet cats. Predation by feral cats was listed as a Key Threatening Process under the Federal Endangered Species Protection Act 1992 (now incorporated in the Environment Protection and Biodiversity Conservation Act 1999). A Threat Abatement Plan for Predation by Feral Cats was produced in 1999 and amended in 2008 to promote the recovery of vulnerable and endangered native species and threatened ecological communities (Environment Australia 1999 and DEWHA 2008).
Estimating abundance
The three most common techniques for estimating cat abundance in Australia are spotlighting, counting tracks, and bait uptake estimates. The accuracy of spotlighting is dependent upon the density of vegetative cover and cat behaviour; the accuracy of track counts depends upon where track pads are set and the competence of the operative in recognising tracks; and most bait uptake studies provide data on cat activity rather than relative abundance or densities. All three techniques are best suited to open, dry habitats with low vegetative cover. In wetter, more closed and productive habitats with high vegetative cover, techniques such as remote photography and the analysis of DNA extracted from scats or hairs provide alternatives for estimating abundance or density. Such estimates are a necessary prerequisite for the implementation of control or eradication programs to avoid over- or under-commitment of labour, time and money, and are also necessary to measure the efficacy of management programs.
Techniques for control or eradication
A nationally co-ordinated program of feral cat control across Australia is not feasible, as it is with other introduced species, and control efforts are best targeted at protecting threatened species or habitats. All successful cat eradication programs in Australia have been conducted on islands or within areas bounded by predator-proof fencing, and most have required the use of more than one control method. Successful techniques for the control or eradication of cats on islands have proved largely impractical on the mainland. Hunting, trapping and shooting are time and labour intensive and not economically viable over large areas. Trap-neuter-return is unsuccessful in open populations and not practical over large areas. The introduction of disease (e.g. panleucopaenia) is restricted by the probable impact on owned domestic cats and the low transmission rate amongst widely dispersed feral cats. Toxins presently registered for cat baiting may have unacceptable environmental impacts on many habitats. Research into more felid-specific toxins, cat attracting baits and lures and cat-specific toxin delivery systems may lead to the adoption of poisoning as the most widely used technique for the control or eradication of feral cats.
Management at the regional and local level
Management of feral cats requires reliable data on the density or relative abundance of cats in targeted areas, and analysis of the cost effectiveness and efficacy of the various control measures that may be implemented. At the regional and local level, eradication of cat colonies and the management of resource-rich artificial habitats to discourage colonisation by cats should be an adjunct to any feral cat control program. Implementation of companion animal legislation that requires firmer controls on the owned, domestic cat population is also an important consideration for the longer-term reduction of the feral cat population in Australia.
Factors limiting effective management
Although adequate legislation is in place in some jurisdictions, the problems associated with cat control programs in Australia include: the time, cost and social impacts associated with enforcing companion animal legislation; the acceptance in some states of cats as pest control agents; variable cat densities between habitats; relatively low bait acceptance by feral cats; a lack of programs aimed specifically at stray cat colonies exploiting highly modified habitats; little data on the impact of cat removal on populations of introduced rodents and rabbits; and few accurate estimates of the density or relative abundance of feral cats. Research is needed to define the most successful methods for gaining public acceptance of the importance of maintaining effective companion animal legislation; estimating densities of cats in various habitats; the cost effectiveness of control techniques including broadscale baiting; assessing the impact of the removal of colony-forming cats in resource-rich artificial habitats on the broader feral cat population; and assessing the impact of cat removal on both native and introduced small mammal populations and the further indirect effects of removal on other components of the biota.
Burrowing bettings Bettongia lesueur and golden bandicoots Isoodon auratus were reintroduced from an island off the NW coast of Western Australia to the Gibson Desert on the Australian mainland. Both species quickly adapted to their new mainland habitat and had gained weight within a few weeks. The golden bandicoots also bred well. Measures to control introduced predators successfully reduced dingo Canis familiaris dingo and fox Vulpes vulpes numbers but resulted in increased numbers of feral cats Felis catus. The reintroduced species showed different biological and behavioural traits affecting their vulnerability to predation. Betongs were highly vulnerable to predation by feral cats so it will be difficult to establish this species, and others with similar traits, in the presence of anything but extremely low densities of introduced predators. Golden bandicoots were less vulnerable to predation so it should be possible to establish viable populations of this species in the arid zone, providing introduced predator numbers are significantly reduced and animals are released into areas of optimum habitat. -from Authors
The population dynamics of five remnant rock-wallaby populations (Petrogale lateralis) persisting on granite outcrops in the central wheatbelt region of Western Australia were monitored over a six year period. From 1979 to 1982 all populations remained relatively static or declined for unknown reasons, but circumstantial evidence implicated fox predation. A fox control program was implemented in 1982 on two outcrops and was maintained for four years with the result that the two resident rock-wallaby populations increased by 138 and 223%. Two rock-wallaby populations occupying sites not subjected to fox control declined by 14 and 85%, and the third population increased by 29%. It was concluded that the fox has probably been a significant factor in the demise and decline of native mammals in the past, and that surviving populations are still at risk. Control of predation pressure on nature reserves was shown to be feasible from a management perspective.
The mammals of inland Australia were seriously affected by European settlement, and a high proportion declined dramatically in range or became extinct. Native birds fared much better, and no species are certainly extinct. Reptiles have suffered no extinctions and no apparent reductions of range. Among the mammals there are clear biases in the species which suffered most; medium-sized species, most of them herbivorous or omnivorous, were devastated. It proposed that the environment of inland Australia was originally difficult for herbivorous and omnivorous mammals to inhabit because of the infertility of the soils, and the consequent restriction of digestible production to small fertile areas. This problem was exacerbated by the uncertain climate with its droughts of irregular length. The consequent restriction of these types of mammals to scattered pockets of suitable habitat during droughts exposed them to high probabilities of local disappearance. The arrival of grazing stock and the rabbit Oryctolagus cuniculus upset the balance between local disappearance and reinvasion after drought. The introduced herbivores maintained extraordinarily high populations for a short time and, in doing so, altered the vegetational composition of the very habitats upon which the native species had been dependent for refuge during droughts. This degradation, together with the pressure of introduced predators and, in some places, altered patterns of fire, caused increased probabilities of local disappearance. Several droughts later, extinctions resulted. -from Author
Bait uptake by feral cats has shown variability both on a temporal and spatial scale. This study examined whether bait uptake is influenced by short-term weather parameters and/or the time of year and if so, when bait uptake is at its peak. We aimed to determine the optimum timing of baiting programs to maximize efficiency. The result was that bait uptake by feral cats displayed a high degree of short-term variability but clearly became more frequent and consistent into late summer/early autumn. A number of temperature factors were significantly related to bait uptake over the entire sampling period (long-term weather conditions) but insignificant when bait uptake was a regular occurrence. The exception was fluctuations in minimum temperature, which was of significance in both the long and short-term. Of the other environmental factors, rabbit abundance had a significant relationship with bait uptake. As rabbit abundance decreased from late spring through to early autumn, there was an increase in bait uptake. The two most important environmental factors that affected bait uptake in the short-term were wind speed and fluctuations in minimum temperature. There was a significant preference for the kangaroo meat sausage bait over a chicken meat sausage bait and day-old cockerel and this could be potentially enhanced by the use of visual lures. Baiting efficacy was also significantly affected by non-target species, particularly Varanids and Corvids, consuming baits, reducing bait availability to feral cats.
The coyote (Canis latrans) is a common resident in urban areas throughout the United States, yet little is known about coyote diets in these environments. I characterized the annual diet of coyotes in an urban environment of western Washington by analyzing their scat from three areas representing typical patterns of human occupation and density: residential (1413 humans/km2), mixed agricultural residential (348 humans/km2), and mixed forest-residential (126 humans/km2). Coyote scats were collected twice a month for 1 year (Nov. 1989-Oct. 1990) in each habitat type. Fruits and mammals were the largest classes of food items in all habitat types and their seasonal use was similar among habitats. Apple (Malus spp.) and cherry (Prunus spp.) were the most abundant fruits in the scats, and ranged from 22-41% and 9-13% of the annual diet, respectively. Vole (Microtus spp.) was the most abundant mammalian food item (41.7%) of coyotes in mixed agricultural-residential habitat while house cat (Felis catus) and squirrel (Sciurus spp. and Tamiasciurus spp.) were the two most abundant mammalian food items (13.1 and 7.8%, respectively) of coyotes in residential habitat. No single mammalian species made up >6.0% of the coyote diet in mixed forest-residential habitat. Coyotes in my western Washington study area rely on foods that result from human activity but those foods, particularly mammals, may change as land use patterns change.
