Lethal Control Research Articles

Incorporating geographic context into coyote and wolf livestock depredation research

AbstractApplying research results to new locations and situations can be confounded by differences in the geographic context between the original and the applied study sites. Replication studies and meta‐analyses may be similarly hindered. We investigated how often canid management research reports (e.g., journal articles, conference proceedings) included information on historical/current lethal control, alternative prey availability, landscape features, and seasonal and settlement characteristics. We included experimental research published between 1970 and 2018, focusing on livestock depredations by wolves and coyotes in North America. Reporting on contextual factors was highly variable; seasonal context was included in 83% of research findings; human settlement characteristics were reported in only 8%. Contextual information was more common in journal versus grey literature, and in reports with academic versus government‐affiliated primary authors. Discussions of the effects of contextual factors on livestock depredation mitigation strategies were underdeveloped. Yet, geographic context of research is vital; it can alter animal behaviour and reduce the efficacy of applied mitigation. We suggest reporting guidelines to improve comparisons and meta‐analysis opportunities, which may enhance comparisons and management decision making.

Unravelling negative interactions between humans, mammalian carnivores and raptors in South America

Human-wildlife interactions can be negative when the needs and behavior of wildlife negatively influence human goals, or vice-versa, and management of these interactions may lead to conflict. Here, we review information on negative interactions between humans and wildlife in South America contained in 136 scientific publications, focusing on terrestrial mammalian predators and raptors. We found that most studies were conducted in Brazil, Argentina, Chile and Colombia. The methodology most commonly used to investigate negative interactions was interviews with rural inhabitants. Studies were performed mainly on interactions involving large felids such as Panthera onca and Puma concolor, and —to a lesser extent— on other mammalian predators and raptors such as eagles or scavenger birds. The main drivers of negative interactions involved perceived or actual impacts on human economy (material) (e.g., livestock or crop losses) or were based on non-material (intangible) aspects (e.g., fear, myths, and religious beliefs). The studies showed that negative attitudes and perceptions toward terrestrial mammalian predators and raptors are widespread in South America. Although non-lethal strategies for mitigation of negative interactions have been proposed, most are not widely used and lethal controls are still very common. A multidisciplinary approach is required, based on multiple actions (e.g., improving livestock practices, running educational programs, increasing stakeholder involvement, providing farmers with solutions), which would minimize negative interactions and promote coexistence between humans and wildlife. This is key to maintaining threatened species, ecological interactions and healthy environments in the anthropized landscapes of biodiverse South America.

Problematic of human-wildlife conflicts in Kongo central province in the Democratic Republic of the Congo (Africa)

A study on the issue of Human-Wildlife Conflicts (HWC) was carried out from January 1, 2018 to June 30, 2020 in the province of Kongo Central. It consisted of: (1) Identifying the causes of Human-Wildlife Conflicts in the province, (2) Determining the social impacts generated by Human-Wildlife Conflicts and (3) Identifying the prevention and mitigation measures applied to resolve the problems of Human-Wildlife Conflicts in the province. Semi-structured surveys were carried out on the basis of an interview guide among the populations of 8 territories. The sample size was 384 households per territory chosen by the simple random sampling technique. The results showed that the competition of humans and wildlife for spaces was the leading cause of Human-Wildlife Conflicts in Kongo Central province to have been cited in 41.16% of the responses of the respondents. The loss of agricultural or pastoral production cited in 27.81% of the respondents' responses would be identified as the most significant socio-economic impact that the populations would suffer. Lethal control would be the preferred measure to prevent conflict in Kongo Central province with 30.44% of citations. Finally, community awareness and compensation by the State in the event of damage would be the measures proposed in 34.93% and 23.57% respectively of the responses of the populations.

Evaluating the utility of pest control sourced rats for zoonotic pathogen surveillance

Norway rats (Rattus norvegicus) inhabit cities worldwide and live in close association with humans. Studies of urban rat zoonoses often rely on live-trapping, with fewer studies using rats sourced through lethal pest control interventions. Our objectives were to evaluate the utility of rats collected by pest control professionals for zoonotic pathogen surveillance and determine whether we could detect Leptospira interrogans and Streptobacillus moniliformis in pest control sourced rats. Rat carcasses were submitted from Windsor, Canada by pest control professionals between November 2018 and March 2020. Submissions were categorized by season and land use. Necropsies were performed to classify carcass quality, collect tissue samples, and record demographic data. The association between carcass quality and the ability to collect tissue samples for pathogen surveillance was assessed via an exact logistic regression model. Using PCR, a subset of kidney and spleen samples were tested for L.interrogans and S.moniliformis, respectively. Our sample of pest control sourced rats had similar sex and age distributions to those of live-trapping studies. Rats were primarily submitted from residential and industrial locations during fall, winter, and spring, which may reflect pest control service areas and peak business periods, rather than rat distribution. Of 124 submissions, 98 (79.0%) of rats showed only mild decomposition. The odds of collecting all tissue samples were reduced for fair compared to good-quality carcasses (OR: 0.029; 95% CI: 0-0.25; p=.0009) and for poor compared to fair-quality carcasses (OR: 0.048; 95% CI: 0.00085-0.53; p=.0065). Leptospira interrogans and S. moniliformis were detected in 9.1% (4/44) and 27.3% (15/55) of a subset of rats tested, respectively. Our results suggest that pest control sourced rats are suitable for surveillance for multiple zoonotic pathogens in urban environments. This method of rat collection may provide preliminary information to guide more detailed ecological studies.

Wolf Conservation and Management in Spain, An Open Debate

Wolf management in Spain is remarkably different at regional scales. South of Douro river, wolves are protected, north of Douro wolves can be hunted, and culling occurs on both sides. After a formal request to include wolves in the Spanish Red List of Threatened Species, wolves have been “listed,” but not as a vulnerable species. Recreational hunting will no longer be a wolf management option, while culling is still allowed. We describe the process to raise wolf protection at the state level, and the factors that should be relevant to guide apex-predator management. Restricting lethal control and favoring predator-prey interactions by reducing livestock depredation should be more feasible with an overarching policy that is binding over the whole range of the species in Spain.

Mind the gap: Comparing expert and public opinions on managing overabundant koalas

Management decisions that do not adequately align with the values and opinions of the public-at-large can lead to controversy and conflict. In conservation and natural resource management, knowledge of the public's values and opinions are often assumed or based on the personal perceptions of experts, rather than on empirical evidence. Mismatches can occur, and in Australia, an ongoing debate about how to best manage overabundant koalas has divided experts and members of the public for decades. On several occasions, experts have recommended culling of overabundant koalas, and yet culls are rarely conducted by managers. Anecdotally this is due to perceived public opposition to the culling of koalas, but there is little empirical evidence to evaluate this assessment. Using a nationwide survey, we investigated the social acceptability of different options for koala management in a population of experts and the general public, and how underlying environmental values and basic beliefs about human-wildlife relationships can explain differences of opinion. We found significant differences in the acceptability of management options between experts and the general public, although the polarity of acceptability was mostly the same. However, the lethal management options of culling and indigenous hunting elicited opposing opinions. Consistent with previous research, beliefs about human-wildlife relationships and belief profiles were found to be useful in explaining differences in acceptability of lethal control among the public, but not among experts. Biospheric values and increased experience and knowledge could play a greater role in the formation of experts' acceptability judgements. Due consideration of evidence-based knowledge of people's opinions can avoid reactive decision-making based on the opinions of a vocal minority. Where differences of opinion exist between experts and the general public, reconciling these divergent views should lead to better conservation outcomes with reduced conflict over potentially controversial management actions.

Knowledge, attitude and practice of the local people towards human–carnivore coexistence in Faragosa–Fura Landscape, Gamo Zone, southern Ethiopia

Local people knowledge, attitudes and practices (KAP) have played an important role in human‐wildlife coexistence and have received increased attention in biodiversity conservation. However, studies on the KAP of local people towards human‐carnivore coexistence (HCC) are scarce, species‐specific or limited to the protected areas. Therefore, we investigated the local people KAP towards carnivore coexistence with humans, the problem of livestock and mitigation practices in a human‐dominated landscape of southern Ethiopia. We collected the data from 352 households interviews using a semi‐structured questionnaire and photographic sampling. The respondents mentioned 13 carnivores coexisting with local people belonging to six families. Eighty‐five percent of the respondents perceived carnivores as problematic species and expressed a negative attitude towards them, primarily due to the damage they caused to their livestock. Respondents who had better knowledge of carnivores also showed a positive attitude towards carnivores. The cluster analysis showed that the spotted hyena, serval, leopard, common genet and black‐backed jackal were grouped under a high‐threat cluster. Chickens and goats were the most threatened livestock reported by respondents. The main predation control methods reported were guarding and fencing for larger livestock and keeping chickens indoors during the night. The regression models predicted that males and literate respondents had better knowledge of carnivores than females and illiterates. The respondents who owned more livestock experienced more damage to livestock, and females showed a negative attitude towards carnivores. Although the study area is the critical conservation value of the 13 carnivore species, livestock predation by carnivores, the local people's negative attitude towards carnivores and lethal predation control methods practiced by local people were affecting HCC in the area. The findings call for conservation actions such as conservation education to raise awareness and develop a positive attitude and non‐lethal predation mitigation measures to promote HCC in consultation with the local community.

Large-Scale Sheep Losses to Wolves (Canis lupus) in Germany Are Related to the Expansion of the Wolf Population but Not to Increasing Wolf Numbers

Recovery of predator populations triggers conflicts due to livestock depredation losses, particularly in Germany where the wolf (Canis lupus) population grows exponentially and livestock (especially sheep) losses raise public concerns and motivate the authorities to control wolf numbers. Yet, the effects of wolf numbers and alternative factors, such as abundance of prey and livestock, on livestock losses in this country are not investigated. In this study, we collected and analyzed data on the numbers of reproductive units of wolves (packs and pairs together) as a surrogate of adult wolf numbers, sheep killed by wolves, living sheep, red deer (Cervus elaphus), roe deer (Capreolus capreolus), and wild boar (Sus scrofa) in every German state and year from 2002 to 2019. We applied a negative binomial Generalized Linear Mixed Model (GLMM) to estimate the effects of these predictors on the numbers of sheep killed by wolves. We also examined the relationships between the percentages of killed/living sheep and the numbers of living sheep. Ranking of 63 models based on the Akaike information criterion revealed that sheep losses were determined by state, year, and number of living sheep, not by wolf numbers, at high precision and accuracy. The number of sheep killed by wolves increased consistently by 41% per year and by 30% for every additional 10,000 sheep, mainly in the north where most wolf territories are concentrated. This means that sheep are protected insufficiently and/or ineffectively. The percentages of killed/living sheep consistently increased by 0.02–0.05% per state and year, with the maximum percentage of 0.7%, on a backdrop of decreasing numbers of living sheep. In conclusion, we demonstrate that sheep losses in Germany have been driven by the expansion of the wolf population, not by wolf numbers, and by the number of sheep available. We suggest that Germany’s wolf conservation policy should focus on alternative non-lethal interventions, enforcement and standardization of intervention monitoring, and promotion of wolf tolerance rather than on lethal control of wolf population size.

A comparison of methods for monitoring a sparse population of the red fox (Vulpes vulpes) subject to lethal control using GPS telemetry, camera traps and sand plots

Context The introduced red fox has driven the decline or extinction of numerous wildlife species in Australia, yet little information exists on the population densities of foxes in most ecosystems. Fox monitoring programs will differ widely depending on the goals of management, which, in turn, will determine whether the appropriate metric is a density estimate, or some proxy thereof, and the time and resources required. Aims This study aims to assist wildlife managers to design fit-for-purpose monitoring programs for foxes by providing a better understanding of the utility and precision of various monitoring methods. Methods We surveyed foxes monthly over four consecutive years in a semi-arid region of Australia by using sand plots, camera traps and GPS telemetry. The resultant data were used to produce population estimates from one count-based method, two spatially explicit methods, and two activity indices. Key results The incorporation of GPS-collar data into the spatial capture–recapture approaches greatly reduced uncertainty in estimates of abundance. Activity indices from sand plots were generally higher and more variable than were indices derived from camera traps, whereas estimates from N-mixture models appeared to be biased high. Conclusions Our study indicated that the Allen–Engeman index derived from camera-trap data provided an accurate reflection of change in the underlying fox density, even as density declined towards zero following introduction of lethal control. This method provides an efficient means to detect large shifts in abundance, whether up or down, which may trigger a change to more laborious, but precise, population monitoring methods. If accuracy is paramount (e.g. for reintroduction programs) spatially explicit methods augmented with GPS data provide robust estimates, albeit at a greater cost in resources and expertise than does an index. Implications Our study demonstrated that the shorter the survey period is, the greater is the likelihood that foxes are present but not detected. As such, if limited resources are available, longer monitoring periods conducted less frequently will provide a more accurate reflection of the underlying fox population than do shorter monitoring periods conducted more often.

A review of nonlethal and lethal control tools for managing the damage of invasive birds to human assets and economic activities

A review of nonlethal and lethal control tools for managing the damage of invasive birds to human assets and economic activities

Longevity of an immunocontraceptive vaccine effect on fecundity in rats

•Increases in human-wildlife conflicts alongside cultural shifts against lethal control methods are driving the need for alternative wildlife management tools such as fertility control. Contraceptive formulations suitable for oral delivery would permit broader remote application in wildlife species.•This study evaluated the contraceptive effect and immune response to two novel injectable immunocontraceptive formulations targeting the Gonadotropin Releasing Hormone (GnRH): MAF-IMX294 and MAF-IMX294P conjugates, both identified as having potential as oral contraceptives. The study also explored whether in multiparous species immunocontraceptives may either totally prevent reproduction or also affect litter size.•Female rats, chosen as a model species, were given three doses of either MAF-IMX294 or MAF-IMX294P to compare anti-GnRH immune response and reproductive output up to 310 days post-treatment.•Both formulations induced anti-GnRH antibody titres in 100% of rats and significantly impaired fertility compared to control animals. Following treatment with MAF-IMX294 and MAF-IMX294P 0 of 9 and 1 of 10 females respectively produced litters following the first mating challenge 45 days post-treatment, compared to 9 of 9 control animals.•Across the whole 310 day study period 7 of 9 females from the MAF-IMX294 group and 10 of 10 females in the MAF-IMX294P group became fertile, producing at least one litter throughout six mating challenges.•No significant differences were found between the two formulations in antibody titre response or duration of contraceptive effect, with an average time to first pregnancy of 166 days for MAF-IMX294 and 177 days for MAF-IMX294P for all females that became fertile.•Following treatment with MAF-IMX294 and MAF-IMX294P the first litter produced post-infertility in treated females was significantly smaller than in control animals. This indicates treatment with immunocontraceptives may induce an overall suppression of fecundity extending past an initial infertility effect. This increases the potential long-term impact of these immunocontraceptives in multiparous species such as commensal rodents.

Efficacy and Cost of GonaCon™ for Population Control in a Free‐ranging White‐tailed Deer Population

ABSTRACTAs white‐tailed deer populations increase in developed and urban areas, lethal management is necessary to control population growth. However, concerns about safety and negative attitudes towards lethal control and using firearms near houses have prompted many communities to pursue nonlethal techniques. Therefore, in 2014 we initiated a 5‐year project to attempt to stabilize the local deer population on Bald Head Island (BHI), North Carolina, using the immunocontraceptive GonaCon™. Since 2014 we captured and inoculated 77 female deer with GonaCon™. From 2017 to 2018 we evaluated the efficacy and cost of GonaCon™ at reducing pregnancy in adult female white‐tailed deer on BHI. We obtained blood samples from 49 deer that had received either 1 or 2 doses of GonaCon™, and from 19 female deer that had received no GonaCon™ for pregnancy analysis using the pregnancy specific protein B assay. All untreated deer sampled were pregnant (n = 19), whereas 67% of deer sampled that received only a single dose were pregnant (n = 27), and 14% of deer that received 2 doses (n = 22) were pregnant. Thus, 2 doses of GonaCon™ were necessary to reduce pregnancy rates below 50%. The total direct cost of the 5‐year immunocontraception project was $320,030.52 and averaged $2,078.12/capture with an overall efficacy of 33% for one dose and 86% for 2 doses of GonaCon™. Conversely, the estimated cost for the local government (i.e., Village of Bald Head Island) to cull 30 deer in 2018 was $16,163.63, or $538.79/deer. The estimated deer population was 113 in 2014 and increased to 198 individuals by 2018. Further population projections suggested the white‐tailed deer population is projected to reach 342 individuals by 2022. Although 2 doses of GonaCon™ were effective at reducing pregnancy, administration across the BHI deer population was not successful in reducing the deer population, and culling will likely be necessary to reduce the population. © 2021 The Wildlife Society.

Conservation Letter: Raptors and Anticoagulant Rodenticides

Conservation Letter: Raptors and Anticoagulant Rodenticides

The case for case studies: A new approach to evaluating the effectiveness of livestock protection tools

Livestock operations in California face livestock losses due to a range of carnivore species. Simultaneously, there is an increased call to reduce the use of lethal predator control methods and replace them with nonlethal methods. Livestock guardian dogs (Canis lupus familiaris) are one such nonlethal livestock protection tool (LPT), yet research is still lacking on the factors and situations that impact their effectiveness. Using three case studies, we demonstrate the value of objective analyses that explicitly address the inherent differences in ranch management, environment, and surrounding land uses in examining livestock guardian dogs as an LPT. We used semi-structured questionnaire surveys of livestock operators to collect information on effectiveness, behavior, and producer satisfaction of LGDs protecting poultry (Gallus gallus domesticus), calves (Bovus taurus), and sheep (Ovis aries) on private and public land and in conjunction with a variety of other livestock protection tools. We aimed to address all aspects related to the use of LGDs as a means of informing livestock operators’ decisions on whether LGDs are an appropriate tool for a particular operation. The case studies demonstrated the complexities involved in applying LGDs as a LPT within the context of a livestock operation. In two of the three case studies, LGDs did not entirely eliminate livestock losses yet operator satisfaction remained high.

Surviving the Urban Jungle: Anthropogenic Threats, Wildlife-Conflicts, and Management Recommendations for African Crowned Eagles

Larger carnivores often trigger human-wildlife conflicts that arise from perceived threats to humans and domestic animals’ safety, which generate the need for management and removal strategies. These issues become especially challenging when humans and wildlife coexist close to one another, for example, in urban landscapes. African Crowned Eagles (Stephanoaetus coronatus) are powerful forest raptors that breed within the metropolitan green-space system of Durban and Pietermaritzburg, South Africa. Negative human-wildlife interactions can occur because eagles occasionally predate on pets, such as cats (Felis catus) and small dogs (Canis lupus familiaris), and provisioning domestic stock to nest sites has previously been quantified. Here, wildlife management becomes critical, usually aimed at reducing or eliminating causes of economic or social harm, but have to be balanced against conservation goals regarding threatened species. In this study, we (i) identified causes of harm or loss of Crowned Eagles because of injuries (n = 53 incidents; 31 mortalities); and (ii) describe interactions with negative perceptions to human livelihoods, particularly concerning predation on pets and livestock. Anthropogenic causes of mortality were more likely to be reported than remote natural deaths, which provides important opportunities for mitigation measures. Most avoidable are electrocution on utility poles, persecution via gunshot wounds and poisoning (targeted or secondary), while collisions with anthropogenic structures, such as glass panes, vehicles and fence wires, are more challenging to mitigate. Out of 44 verified Crowned Eagle vs. pets and livestock conflicts, we documented 19 dog attacks (2012–2020), with detrimental impacts on social perception and acceptance of urban eagles. Pet and livestock conflicts were primarily associated with juveniles and immature eagles (83%). Of these, 19% occurred during September alone, which marks the end of the post-fledging dependency period; 70% occurred outside the breeding season. We provide management recommendations regarding various categories of Crowned Eagle human-wildlife interactions. For example, activities such as rehabilitation and falconry can coordinate to achieve a high standard of public support and conservation outcomes for Crowned Eagles. Finally, we discuss using different management intervention strategies, including rehabilitation, falconry, re-wildling processes, and lethal control of specific “problem” individuals toward achieving the goal of sustainable, healthy Crowned Eagle populations that coexist with humans in urban landscapes.

A “Wicked Problem” Reconciling Human-Shark Conflict, Shark Bite Mitigation, and Threatened Species

Conservation measures often result in a “wicked problem,” i.e., a complex problem with conflicting aims and no clear or straightforward resolution without severe adverse effects on one or more parties. Here we discuss a novel approach to an ongoing problem, in which actions to reduce risk to humans, involve lethal control of otherwise protected species. To protect water users, nets are often used to catch potentially dangerous sharks at popular bathing beaches, yet in Australian waters one of the targeted species, the white shark (Carcharodon carcharias) is listed as Vulnerable, while bycatch includes the Critically Endangered grey nurse shark (Carcharias taurus). Recent, highly publicised, shark attacks have triggered demands for improved bather protection, whilst welfare and conservation organisations have called for removal of lethal measures. This leaves management and policy makers with a wicked problem: removing nets to reduce impacts on threatened species may increase risk to humans; or leaving the program as it is on the premise that the benefits provided by bather protection are greater than the impact on threatened and protected species. We used multivariate analysis and generalised additive models to investigate the biological, spatial-temporal, and environmental patterns influencing catch rates of threatened and of potentially dangerous shark species in the New South Wales shark nets over two decades to April 2019. Factors influencing catches were used to develop a matrix of potential changes to reduce catch of threatened species. Our proposed solutions include replacing existing nets with alternative mitigation strategies at key beaches where catch rate of threatened species is high. This approach provides stakeholders with a hierarchy of scenarios that address both social demands and threatened species conservation and is broadly applicable to human-wildlife conflict scenarios elsewhere.

Evaluating the evidence of culling a native species for conservation benefits

AbstractControlling problem species for conservation can be fraught, particularly when native species are subject to lethal control. The noisy miner (Manorina melanocephala), has been the target of numerous lethal control efforts. Outcomes of these noisy miner removals have varied substantially, so identifying the circumstances under which they are effective is essential for ethical and effective management. We compiled data for all identified noisy miner removals (n = 45), including both permit‐based and unofficial removals. We investigated whether methodological and ecological factors explained the effectiveness of removals in reducing noisy miner density or increasing woodland bird richness and abundance. The only predictor of any measure of success was time between first and final culls which was positively related to reduction in noisy miner density. Surprisingly, despite removals mainly failing to reduce noisy miner density to below a threshold above which noisy miners impact smaller birds, woodland birds usually still increased. Disrupted social structure as noisy miners recolonized may have led to less effective aggressive exclusion of small birds. Further removals may not need to reduce noisy miner density to below this threshold to benefit woodland birds, but consistent monitoring and reporting would support better evaluation of effectiveness and correlates of success.

Detection probabilities and surveillance sensitivities for managing an invasive mammalian herbivore

AbstractInvasive mammalian herbivores can have significant unwanted impacts on indigenous ecosystems and production landscapes. Their impacts are often mitigated using sustained lethal control or eradication. If eradication is the chosen option, it is critical to confirm where the pest population is distributed and prove that eradication has been achieved following the removal intervention. This form of pest management requires robust and quantitative estimates of surveillance. We compared the detection probabilities, derived surveillance system sensitivities (under standardized conditions), and cost of surveillance for four survey methods for invasive Bennett’s wallabies (Notamacropus rufogriseus) in South Island, New Zealand: helicopter surveys with observers, helicopter surveys using a thermal imaging camera, a ground hunter with detector dogs, and camera traps. We found camera traps and ground hunters with dogs were the most sensitive surveillance methods (82% and 45% chance of detecting a wallaby assuming full search coverage of a 100‐ha area, respectively) and were most cost‐effective (62% and 85% cheaper than helicopter surveys with observers, respectively). However, although these methods are useful for surveying small areas (~1000 ha or less), capacity and time issues make them impractical for surveying large areas. The helicopter‐based methods will likely be more suitable for monitoring large areas (e.g., 10,000–50,000 ha) that need to be completed more rapidly than could be achieved using ground‐based methods. The model that we used for evaluating detection probability and surveillance sensitivity for different survey methods is highly applicable for managing a wide range of mammalian pests and confidently declaring their absence from an area.

Efficacy and safety of Eradicat® feral cat baits in eastern Australia: population impacts of baiting programmes on feral cats and non-target mammals and birds

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.

Defining practical and robust study designs for interventions targeted at terrestrial mammalian predators

Conflicts between humans and mammalian predators are globally widespread and increasing, creating a long-lasting challenge for conservation and local livelihoods. Protection interventions, which are essential to conflict mitigation, should be based on solid evidence of effectiveness produced by robust study designs. Yet, it is unclear what study designs have been used in predator-targeted interventions and how they can be improved to provide best practices for replications. I examined how applications of five study designs (before-after, before-after-control-impact, control-impact, crossover [i.e., the same randomly assigned study units acting as treatments and controls during alternating trials], and randomized controlled trial) have changed over time and how these changes are related to authors, predator species, countries, and intervention types (aversion, husbandry, mixed interventions, invasive management, lethal control, and noninvasive management). I applied multinomial regression modeling to 434 cases (28 predator species and 45 countries) from 244 studies published from 1955 to 2020. Study design was related only to intervention type. Less reliable before-after and control-impact studies were the most common (47.7% and 38.2% of cases, respectively), and their use increased over years as did all interventions. The contribution of the most robust before-after-control-impact (7.4%), randomized controlled trial (5.3%), and crossover designs (1.4%) remained minor over time. Crossover is suitable for aversion, most husbandry techniques, and a few other interventions, but crossover interventions also have the most limitations in terms of applicability. Randomized controlled trial is generally applicable, but impractical or inappropriate for some interventions, and before-after-control-impact appears to be the most widely applicable study design for predator-targeted interventions.