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Context. Many invasive animals are typically active across large areas, making monitoring and control programs expensive. To be efficacious, monitoring devices and control tools need to be strategically located to maximise the probability of encounter. This requires an understanding of how the target species uses the landscape, through identifying key habitat or landscape features that are preferred and used disproportionately more frequently by the species. Spatial analysis of animal movements can help identify high use areas. Aims. The variability introduced by different range calculation methods can lead to uncertainty in subsequent habitat analyses. We aimed to determine which method is superior for accurate delineation of core areas for feral cats. Methods. We analysed spatial data from 35 collared feral cats across four Australian study sites between 2016 and 2019, and compared the core areas generated using seven commonly used home range estimation methods. Key results. We found that the a-hull method provided a higher precision of polygon placement, resulting in lower Type I and II errors and higher conformity to landscape features than other methods. The a-hull used a single default parameter and required no subjective input, making it a more objective, superior method. Conclusions. We recommend that the a-hull method be used to define core activity areas for feral cats, enabling more robust habitat analysis, and identification of key habitat and landscape features to strategically target for monitoring and control programs. Implications. This strategic approach could significantly improve cost efficiencies, particularly where existing management is widely dispersed, and core activity areas are clumped. [ABSTRACT FROM AUTHOR]

Reducing the damage caused by feral cats (Felis catus) to wildlife, livestock and human health is a key objective for many land managers and human health agencies globally. The lack of safe and efficacious lethal control tools in many regions, however, makes the control of feral cats and their impacts challenging. We performed a baiting trial in central Queensland to measure the efficacy and safety of Eradicat®, a feral cat bait currently approved for use only in the state of Western Australia, as a potential tool for the broadscale control of feral cats in eastern Australian environments. We used camera traps, cat-borne GPS collars and chemical residue analysis to monitor mortality and changes in feral cat populations following baiting. We also used camera traps and bird count surveys to monitor the response of key at-risk non-target species, specifically wild dogs (Canis familiaris), common brush-tailed possums (Trichosurus vulpecula) and 10 bird species at risk of consuming baits. Feral cat abundance reduced significantly (29–40%) following baiting, with reductions observed across 83% of the site. There were no significant changes in wild dog, possum or potentially bait-consuming bird populations following baiting. Our findings suggest that Eradicat® could potentially be a safe and efficacious tool for the landscape control of feral cats at some sites in eastern Australia. Future research is required to test the safety and efficacy of Eradicat® at other sites in eastern Australia, as suites of non-target species will vary among sites in different environments. [ABSTRACT FROM AUTHOR]

Feral cats (Felis catus) pose a significant threat to wildlife, agriculture, and human health through predation, disease transmission, and competition with native animals. Controlling feral cats and their impacts, however, is challenging. New and emerging 1080‐based feral cat baits have shown promising results in western and central Australia; however, the safety of these new baits for nontarget species in eastern Australia, where many native animals are more sensitive to compound 1080 (sodium fluoroacetate) than their western conspecifics, has not been assessed. We investigated the uptake of 499 toxic Eradicat® baits by nontarget animals across five different eastern Australian environs and the uptake of nontoxic Eradicat and Hisstory® baits at an additional two sites. Using field‐based observations of species eating or removing baits, we determined that 13 nontarget species (eight mammals, four birds, and one reptile) were at high risk of individual mortality, with individuals of 11 of those 13 species (seven mammals, four birds) observed consuming enough toxic Eradicat in a single visit to ingest a lethal dose of 1080. Feral cats (the target species) consumed only 3.1% of monitored baits, which was only 52% of the 31 baits they encountered. We recommend undertaking targeted population monitoring of species identified at high risk of individual mortality, to determine whether Eradicat baits present a population‐level risk to these species. Our findings suggest that the small‐sized Eradicat baits present a greater risk to nontarget species in eastern Australia than the larger traditional 1080‐based meat baits used for the control of wild dogs and foxes. Our study highlights the importance of performing risk assessments for different bait types, even when the same toxin is used, and of performing site‐specific nontarget risk assessments of new baits such as Eradicat to assist developing guidelines for their safe and effective use in different environs. Integr Environ Assess Manag 2022;18:224–244. © 2021 State of Queensland. Integrated Environmental Assessment and Management © 2021 SETAC. KEY POINTS: New feral cat baits have shown promising results in western and central Australia and are considered safe for many non‐target native species in those regions due to a long‐term evolutionary exposure to fluoroacetate‐bearing plants, giving them an increased tolerance to the toxin used in baits. We present a comprehensive field assessment of the risk of Eradicat® feral cat baits to non‐target species in eastern Australian environs, where native animals do not share the same evolutionary exposure and tolerance to the toxin as their western conspecifics. Most baits were swiftly removed by non‐target native mammals, birds and reptiles, 13 of which were at high risk of individual mortality, with most species consuming more than enough toxic bait in a single visit to ingest a lethal dose. Our findings will help inform operational risk assessments, thereby enabling land managers to adapt control programs to manage non‐target risks to local faunal communities on a site‐by‐site basis in accordance with local management requirements and objectives. [ABSTRACT FROM AUTHOR]

The role of apex predators in structuring ecosystems through the suppression of mesopredator activity and abundance is receiving increasing attention, largely due to the potential benefits for biodiversity conservation. In Australia, invasive mesopredators such as feral cats (Felis catus) have been identified as major contributors to Australia's mass mammal extinctions since European arrival. The introduced dingo (Canis familiaris) has been proposed as a novel way to suppress the impacts of feral cats, however, scientific evidence of the dingo's suppressive role is equivocal.We used camera traps to investigate whether a large introduced predator (dingo) suppresses the activity of an established introduced mesopredator (feral cat) across a national park site conserving endangered species, and an agricultural site supporting cattle grazing enterprises.Feral cats and dingoes exhibited marked overlap in both temporal and spatial activity, indicating coexistence. Some temporal separation was evident at the agricultural site, however, this reflected higher diurnal activity by dingoes, not a responsive shift in cat activity. Cat activity times were unrelated to dingo presence and did not differ between areas occupied by dingoes and dingo‐free areas. There was no evidence of dingoes excluding cats from patches at either site, nor was there evidence of within‐night fine‐scale spatiotemporal avoidance of dingoes by cats.Species co‐occurrence models revealed dingoes had no negative effect on the probability of cat presence. The probability of detecting a cat on the national park was significantly higher in areas with dingoes than in dingo‐free areas, while on agricultural land, cat detectability did not differ between areas with and without dingoes. Cats remained active, abundant and widespread across both sites, with evidence of cats hunting and breeding successfully in areas occupied by dingoes.Synthesis and applications. Our findings indicate that feral cats can coexist with dingoes, without apparent suppression of cat activity, abundance or fitness. Proposals to reintroduce or restore dingoes and other large predators to suppress invasive mesopredators and conserve biodiversity should be carefully evaluated on a site‐by‐site basis, as their ability to suppress cats and protect species of conservation significance will likely be context dependent. [ABSTRACT FROM AUTHOR]

Camera traps are now the most commonly used technique for indexing feral cat (Felis catus) and predator populations. Camera flash-type has been suggested to influence an animal's behaviour and their redetection by similar cameras, with white-flash cameras being shown to reduce the probability of redetecting some species. We investigated the influence of camera flash-type on the behaviour of feral cats by categorising their behavioural response to white-flash and infrared-flash cameras and assessing the frequency with which individual cats were redetected by the same white-flash camera or a different white-flash camera at the same site following their initial detection. We found no evidence that flash type had any influence on the cats' observed behavioural responses towards cameras, or that cats captured by white-flash cameras avoided redetection. Our findings suggest that white-flash cameras are suitable for the detection and redetection of cats, and provide better-quality images from which to identify individual cats. We investigated the influence of camera-trap flash type on the behaviour of feral cats by categorising their behavioural response to white-flash and infrared-flash cameras and assessing the frequency with which individual cats were redetected by the same white-flash camera or a different white-flash camera at the same site following their initial detection. We found no evidence that flash type had any influence on the cats' observed behavioural responses towards cameras, or that cats captured by white-flash cameras avoided redetection. [ABSTRACT FROM AUTHOR]

Reducing the impacts of invasive predators is a key objective for conservation managers, livestock producers and human health agencies globally. The efficacy of invasive predator control programs, however, is highly variable. To improve control efficacy, managers require a fundamental understanding of the factors that contribute to the success or failure of a control program. Using a predator baiting program as a case study, we measured the efficacy of baiting as a control tool to significantly reduce feral cat (Felis catus) populations. We used camera traps and cat-borne GPS collars to monitor changes in feral cat populations at a baited site and an unbaited site, using a Before-After, Control-Impact (BACI) design. We also identified five key elements required for a successful baiting program (bait encounter rate, availability, attractiveness, palatability and lethality) and simultaneously measured these to identify areas for potential improvement. Baiting was ineffective at reducing feral cat populations; collared cat mortality was only 11% (1/9), with camera traps revealing negligible reductions in the number of cat detection events (9%), naïve occupancy (15%), and no significant change in the relative abundance of feral cats (F 1,54 = 0.8641, P = 0.357). Several factors contributed to the poor control efficacy. Bait encounter rates were low, with cats active along tracks (where baits were laid) < 4% of the time. Cats encountered only 14% (7/50) of monitored baits, but none were eaten. Initially, baits appeared attractive to cats; however meat ants and desiccation rapidly decreased bait palatability. Bait availability to cats declined rapidly, with 36% of monitored baits (18/50) removed by non-target species within the first 48 h. The mortality of one collared cat and chemical assays confirmed that, on average, each bait contained sufficient 1080 to kill a large (>5 kg) feral cat. Our findings suggest that altering bait deployment patterns, increasing bait densities and improving bait palatability could potentially improve the efficacy of baiting programs to reduce feral cat populations. Our study provides a framework to measure and evaluate the key elements that contribute to efficacy of pest control programs, and to identify opportunities for improving outcomes of future control programs. • Invasive predator control programs often achieve variable levels of success. • To be effective, control tools such as baits need to be encountered, available, attractive, palatable and lethal. • To increase control efficacy, we need to understand these criteria and how they could be improved. • Low bait encounter rates, availability and rapid unpalatability contribute to failure of feral cat baiting programs. • Increased baiting densities, off-track deployment and improved palatability could increase efficacy of feral cat baits. [ABSTRACT FROM AUTHOR]