Effectiveness of scat-detection dogs in determining species presence in a tropical savanna landscape

Conservation detection dogs: A critical review of efficacy and methodology

Conservation detection dogs (CDD) use their exceptional olfactory abilities to assist a wide range of conservation projects through the detection of target specimens or species. CDD are generally quicker, can cover wider areas and find more samples than humans and other analytical tools. However, their efficacy varies between studies; methodological and procedural standardisation in the field is lacking. Considering the cost of deploying a CDD team and the limited financial resources within conservation, it is vital that their performance is quantified and reliable. This review aims to summarise what is currently known about the use of scent detection dogs in conservation and elucidate which factors affect efficacy. We describe the efficacy of CDD across species and situational contexts like training and fieldwork. Reported sensitivities (i.e. the proportion of target samples found out of total available) ranged from 23.8% to 100% and precision rates (i.e. proportion of alerts that are true positives) from 27% to 100%. CDD are consistently shown to be better than other techniques, but performance varies substantially across the literature. There is no consistent difference in efficacy between training, testing and fieldwork, hence we need to understand the factors affecting this. We highlight the key variables that can alter CDD performance. External effects include target odour, training methods, sample management, search methodology, environment and the CDD handler. Internal effects include dog breed, personality, diet, age and health. Unfortunately, much of the research fails to provide adequate information on the dogs, handlers, training, experience and samples. This results in an inability to determine precisely why an individual study has high or low efficacy. It is clear that CDDs can be effective and applied to possibly limitless conservation scenarios, but moving forward researchers must provide more consistent and detailed methodologies so that comparisons can be conducted, results are more easily replicated and progress can be made in standardising CDD work.

Threats to the conservation of the vulnerable giant anteater (Myrmecophaga tridactyla) in the Cerrado biome: a retrospective survey

In this study, we conducted a retrospective survey of 63 giant anteaters (Myrmecophaga tridactyla) using the Federal University of Uberlândia, Minas Gerais State, Brazil as reference site for wild animals. We analyzed the clinical records of 63 animals from January 2016 to February 2020. The information obtained included the location where the anteater was found, the reason for rescue, estimated life stage, gender, weight, general condition of the animal, clinical signs, diagnosis, and destination. Of the 63 animals, 30.15%, (n = 19/63) were found in rural areas, 25.40% (n = 16/63) in urban areas, and 22.22% (n = 14/63) near highways. The main reason for rescue was run-over accidents (n = 18/63, 28.60%). Regarding life stage distribution, 27% (n = 17/63) were cubs, 25.40% (n = 16/63) were adolescent, and 41.26% (n = 26/63) were adults. There was a higher frequency of females (n = 35/63, 56%), and three (9%) of them were pregnant or had cubs. For injury evaluation, three of the 63 giant anteaters were dead on arrival at the rehabilitation site; therefore, we excluded them from this aspect of the study. Of the 60 remaining anteaters, only 13.33% (n = 8/60) of the animals were healthy upon physical examination.The most common condition was traumatic brain injury (n = 32/60 53.33%), followed by fractures (n = 23/60, 38.33%), neonate triad (n = 15/60, 25%), and abrasions (n = 15/60, 25%). The animals presented a high mortality rate (n = 39/60, 65%). The low number of giant anteaters reintroduced to their natural habitat and the high mortality rate of animals sent to rehabilitation centers show that the protection of giant anteaters is important to reduce the number of these animals sent to rehabilitation centers.

Eyes, ears, or nose? Comparison of three non-invasive methods to survey wolf recolonisation

The development and use of cost-effective and appropriate survey methods to assess species distribution and to monitor range expansion and contraction of wild populations is crucial due to the limited financial resources for conservation. Of particular importance, yet little studied, is the ability to collect information before a wild population is well established, i.e. at the early stages of recolonisation. During 2018 and 2019, we used camera traps, audio recorders, and scat detection dogs simultaneously to investigate composition, detection probability, and territorial extent of a pack of wolves in the Swiss Alps. We compared the efficacy of these survey methods by assessing sampling effort, data obtained, and costs. We show that, under the presented setup, camera traps and scat detection dogs substantially outperformed audio recorders in detecting wolves, representing the packs’ territorial extent, and revealing the number of adult wolves. The detection dogs did not detect pups but, unlike the other methods, allowed the identification of single individuals. The use of four camera traps during 13 weeks, a 24-km-long transect walked with the detection dog, or the use of one audio recorder during 148 weeks were necessary to obtain a comparable wolf detection probability. Our results show that no single method was able to return all information that we hoped to collect. Comprehensive and cost-effective information was best obtained by combining data from camera traps and detection dogs. We suggest both methods to be simultaneously used to successfully investigate wolf recolonisation into historical range.

Pest detection dogs for wood boring longhorn beetles

Invasive alien species are increasing due to globalization. Their spread has resulted in global economic losses. Asian [Anoplophora glabripennis (Motschulsky)] (ALB) and citrus [A. chinensis (Forster)] (CLB) longhorn beetles are two introduced wood borers which contribute to these economic losses e.g. the destruction of tree plantations. Early detection is key to reduce the ecological influence alongside the detrimental and expensive eradication. Dogs (Canis lupus familiaris) can detect these insects, potentially at an early stage. We trained two privately owned dogs to investigate their use as detection tools. We tested the dog's ability to discriminate ALB and CLB from native wood borers by carrying out double-blind and randomized experiments in three search conditions; (1) laboratory, (2) semi-field and (3) standardized field. For condition one, a mean sensitivity of 80%, specificity of 95% and accuracy of 92% were achieved. For condition two and three, a mean sensitivity of 88% and 95%, specificity of 94% and 92% and accuracy of 92% and 93% were achieved. We conclude that dogs can detect all types of traces and remains of ALB and CLB and discriminate them from native wood borers and uninfested wood, but further tests on live insects should be initiated.

Enhancing the Selection and Performance of Working Dogs

Dogs perform a variety of integral roles in our society, engaging in work ranging from assistance (e.g., service dogs, guide dogs) and therapy to detection (e.g., search-and-rescue dogs, explosive detection dogs) and protection (e.g., military and law enforcement dogs). However, success in these roles, which requires dogs to meet challenging behavioral criteria and to undergo extensive training, is far from guaranteed. Therefore, enhancing the selection process is critical for the effectiveness and efficiency of working dog programs and has the potential to optimize how resources are invested in these programs, increase the number of available working dogs, and improve working dog welfare. In this paper, we review two main approaches for achieving this goal: (1) developing selection tests and criteria that can efficiently and effectively identify ideal candidates from the overall pool of candidate dogs, and (2) developing approaches to enhance performance, both at the individual and population level, via improvements in rearing, training, and breeding. We summarize key findings from the empirical literature regarding best practices for assessing, selecting, and improving working dogs, and conclude with future steps and recommendations for working dog organizations, breeders, trainers, and researchers.

Protected areas and unpaved roads mediate habitat use of the giant anteater in anthropogenic landscapes

The drastic reduction of the Brazilian Cerrado has transformed this savanna hotspot into vast swaths of commodity-based agriculture fields, mainly soybean, sugarcane, and beef-production pasturelands. The resulting habitat loss and fragmentation are the principal factors underlying population decline of native species inhabiting the Cerrado, particularly those with a high demand for space, low population density, and specialized diet, such as the endangered giant anteater (Myrmecophaga tridactyla). Although the species has been studied in protected areas, we know much less about its ability to endure in disturbed landscapes. Here, we analyzed camera-trapping data to estimate a proxy of habitat use (ψ^; occupancy) and detection probabilities of the giant anteater, identifying environmental covariates influencing these parameters in landscapes with intensive agriculture and commercial forestry. We found this species using about half of the study area (model average ψ^ = 0.51, CI = 0.40–0.62), with two predictors strongly influencing habitat use: protected areas and unpaved roads. In turn, detection probability correlates positively with area of open Cerrado and negatively with area of settlements. The species is more likely to use unpaved roads inside protected areas (ψ^ = 0.90, CI = 0.47–0.75), compared to off road sites in the surrounding areas (ψ^ = 0.19, CI = 0.10–0.34). Our findings indicate that giant anteaters are dependent on nature reserves and native vegetation areas existing on private properties, whose protection is regulated by the Brazilian Native Vegetation Protection Law. Given the relative paucity of state-owned protected areas in the Brazilian Cerrado, increasing the adherence of rural owners to this law is, therefore, key for the conservation of the giant anteater. The intense use of unpaved roads might reflect travelling and/or foraging optimization, a behavioral response that, nevertheless, may compound this species’ susceptibility to suffer mortality from roadkill.

How quoll-ified are northern and spotted-tailed quoll detection dogs?

Abstract ContextWildlife detection dogs have been used globally in environmental monitoring. However, their effectiveness in the Australian context has been only minimally researched. Increased understanding of detection dog accuracy and efficacy is required for their inclusion in survey guidelines used by proponents of referred actions potentially impacting Australia’s threatened mammals. Evaluation of new methods is also important for advancing population monitoring, particularly for threatened species. AimsTo determine the efficacy of wildlife detection dogs as a survey tool for low-density, cryptic species, using northern (Dasyurus hallucatus) and spotted-tailed (D. maculatus) quolls as subjects. We compared detection dogs, human search effort and camera trapping results, in simulated accuracy and efficacy trials, and field surveys. MethodsTwo wildlife detection dogs’ scores for sensitivity (ability to identify a target species scat) and specificity (ability to distinguish target from non-target species scats) were calculated during accuracy trials. The dogs were tested using 288 samples, of which 32 were targets, where northern and spotted-tailed quoll scat were the targets in separate trials. Survey efficacy was determined following completing 12 simulated surveys (6 per target species) involving a single, randomly placed scat sample in a 1–1.5ha search area. During the northern quoll simulated surveys the dogs’ survey efficacy was compared with that of a human surveyor. The dogs also undertook field surveys for both northern and spotted-tailed quolls, in conjunction with camera trapping for comparison. Key resultsDuring accuracy trials the dogs had an average sensitivity and specificity respectively of 100% and 98.4% for northern quoll, and 100% and 98% for spotted-tailed quoll. Their average search time in efficacy trials for northern quoll was 11.07min (significantly faster than the human surveyor), and 2.98min for spotted-tailed quoll in the 1–1.5ha search areas. During field surveys, northern quoll scats were detected at sites where camera trapping failed to determine their presence. No spotted-tailed quoll scat was detected by the dogs during field surveys. ConclusionsTrained and experienced detection dogs can work very accurately and efficiently, which is vital to their field success. Detection dogs are therefore capable of detecting evidence of species presence where alternative methods may be unsuccessful. ImplicationsOur study supports the future use of highly trained detection dogs for wildlife surveys and monitoring in Australia. Our results demonstrate that detection dogs can be highly accurate and are a beneficial stand-alone or complimentary method.

Jackal in hide: detection dogs show first success in the quest for golden jackal (Canis aureus) scats

Golden jackal (Canis aureus) monitoring in central Europe generates more interest and becomes increasingly important with the species’ appearance in areas where it was previously unestablished. For genetic monitoring of golden jackals via scat collection, the distinction of jackal scats from those of related species such as the red fox (Vulpes vulpes) is crucial: if done incorrectly, it can falsify diet studies or inflate costs of DNA analyses. In this study, we tested the potential benefits of using domestic dogs to specifically find jackal scats. We used trained scat detection dogs to locate and identify golden jackal scats in an area of dense shrubland, with the species’ presence previously confirmed via bioacoustic monitoring. On a total of 133 km of transects covering at least two golden jackal groups, two human-dog teams found 34 putative golden jackal scats. A total of 26 of these were successfully genetically analysed, of which 19 were attributed to 13 individual golden jackals, an accuracy rate of 73%. Our results show that detection dogs can successfully differentiate golden jackal scats from other species. This tool can be applied to detect golden jackal presence and establish more reliable estimates of group number and size than previously determined through bioacoustic stimulation. By combining both methods, questions about family structures and kinship, seasonal differences in habitat use and territory sizes can be answered. The regular use of detection dogs can present an efficient method to monitor golden jackals on a long-term basis and to learn more about their behaviour and population dynamics.

Olfactory Generalization in Detector Dogs

Simple Summary

Dogs are valued for their odor detection capabilities in a vast range of fields. They help to find hidden and elusive targets, such as explosives, narcotics, missing persons, and invasive or endangered species, amongst an extensive list. In all these roles, dogs are required to find real target odors that vary somewhat from those with which they were trained. For example, dogs might be trained with an explosive mixture or certain explosive compounds, and then must be able to find homemade explosives of differing compositions or manufacturing processes. This ability, to respond to similar odors in the same way as they would respond to the originally trained odor, is known as generalization. A failure to generalize can result in dogs missing targets in working scenarios. Although generalization is usually desired to some extent, dogs must also discriminate against related odors that are not targets. Therefore, research that investigates factors that can influence dogs’ tendency to generalize, and conversely to discriminate, can inform training strategies to improve detection outcomes. However, this field requires further research with greater application to practical training.

Abstract

Generalizing to target odor variations while retaining specificity against non-targets is crucial to the success of detector dogs under working conditions. As such, the importance of generalization should be considered in the formulation of effective training strategies. Research investigating olfactory generalization from pure singular compounds to more complex odor mixtures helps to elucidate animals’ olfactory generalization tendencies and inform ways to alter the generalization gradient by broadening or narrowing the range of stimuli to which dogs will respond. Olfactory generalization depends upon both intrinsic factors of the odors, such as concentration, as well as behavioral and cognitive factors related to training and previous experience. Based on the current research, some training factors may influence generalization. For example, using multiple target exemplars appears to be the most effective way to promote elemental processing and broaden the generalization gradient, whereas increasing the number of training instances with fewer exemplars can narrow the gradient, thereby increasing discrimination. Overall, this research area requires further attention and study to increase our understanding of olfactory generalization in dogs, particularly detector dogs, to improve training and detection outcomes.

How Behavior of Nontarget Species Affects Perceived Accuracy of Scat Detection Dog Surveys

Detection dogs, specially trained domestic dogs (Canis familiaris), have become a valuable, noninvasive, conservation tool because they remove the dependence of attracting species to a particular location. Further, detection dogs locate samples independent of appearance, composition, or visibility allowing researchers to collect large sets of unbiased samples that can be used in complex ecological queries. One question not fully addressed is why samples from nontarget species are inadvertently collected during detection dog surveys. While a common explanation has been incomplete handler or dog training, our study aimed to explore alternative explanations. Our trials demonstrate that a scat’s genetic profile can be altered by interactions of nontarget species with target scat via urine-marking, coprophagy, and moving scats with their mouths, all pathways to contamination by nontarget species’ DNA. Because detection dogs are trained to locate odor independent of masking, the collection of samples with a mixed olfactory profile (target and nontarget) is possible. These scats will likely have characteristics of target species’ scats and are therefore only discovered faulty once genetic results indicate a nontarget species. While the collection of nontarget scats will not impact research conclusions so long as samples are DNA tested, we suggest ways to minimize their collection and associated costs.

Detecting rare carnivores using scats: Implications for monitoring a fox incursion into Tasmania

The ability to detect the incursion of an invasive species or destroy the last individuals during an eradication program are some of the most difficult aspects of invasive species management. The presence of foxes in Tasmania is a contentious issue with recent structured monitoring efforts, involving collection of carnivore scats and testing for fox DNA, failing to detect any evidence of foxes. Understanding the likelihood that monitoring efforts would detect fox presence, given at least one is present, is therefore critical for understanding the role of scat monitoring for informing the response to an incursion. We undertook trials to estimate the probability of fox scat detection through monitoring by scat‐detector dogs and person searches and used this information to critically evaluate the power of scat monitoring efforts for detecting foxes in the Tasmanian landscape. The probability of detecting a single scat present in a 1‐km² survey unit was highest for scat‐detector dogs searches (0.053) compared with person searches (x¯≅0.015) for each 10 km of search effort. Simulation of the power of recent scat monitoring efforts undertaken in Tasmania from 2011 to 2015 suggested that single foxes would have to be present in at least 20 different locations or fox breeding groups present in at least six different locations, in order to be detected with a high level of confidence (>0.80). We have shown that highly structured detection trials can provide managers with the quantitative tools needed to make judgments about the power of large‐scale scat monitoring programs. Results suggest that a fox population, if present in Tasmania, could remain undetected by a large‐scale, structured scat monitoring program. Therefore, it is likely that other forms of surveillance, in conjunction with scat monitoring, will be necessary to demonstrate that foxes are absent from Tasmania with high confidence.

Using Scent Detection Dogs in Conservation Settings: A Review of Scientific Literature Regarding Their Selection

Dogs are widely used for scent detection work, assisting in searches for, among other things, missing persons, explosives, and even cancers. They are also increasingly used in conservation settings, being deployed for a range of diverse purposes. Although scent detecting dogs have been used in conservation roles for over 100 years, it is only recently that the scientific literature has begun to document their effectiveness and, importantly, how suitable dogs should initially be selected by organizations wanting to develop a detection program. In this paper, we review this literature, with the aim of extracting information that might be of value to conservation groups considering whether to invest in the use of dogs. We conclude that selection of appropriate dogs is no easy task. While olfactory ability is critical, so also are a range of other characteristics. These include biological, psychological, and social traits. At present, no validated selection tools have been published. Existing organizations have adapted selection instruments from other contexts for their use, but very little published information is available regarding the effectiveness of these instruments in a conservation setting. In the absence of clear guidelines, we urge those wanting to invest in one or more dogs for conservation purposes to proceed with extreme caution and, preferably, under the watchful eyes of an experienced professional.

Scat detection dogs, DNA and species distribution modelling reveal a diminutive geographical range for the Vulnerable small red brocket deer Mazama bororo

The small red brocket deer Mazama bororo is endemic to the Brazilian Atlantic Forest, a biome that has been greatly fragmented and altered by human activities. This elusive species is morphologically similar to the red brocket deer Mazama americana and the Brazilian dwarf brocket deer Mazama nana, and genetic typing is necessary for reliable identification. To determine the geographical range of M. bororo more accurately, we conducted non-invasive genetic sampling using scat detection dogs trained to locate deer faeces. We surveyed 46 protected areas located within the species’ potential distribution and collected a total of 555 scat samples in 30 of the protected areas. Using a polymerase chain reaction–restriction fragment length polymorphism approach, we genotyped 497 scat samples (89%) and detected M. bororo in seven localities in three Brazilian states. The results support a range extension of the small red brocket deer to latitudes 23 and 28°S and longitudes 47 and 49°W. We show that the species’ distribution is associated with 37,517 km2 of the Ombrophilous Dense Forest in the Brazilian Atlantic Forest, and this conclusion is supported by species distribution modelling. The small red brocket deer is the largest endemic species in Brazil and may have the smallest geographical distribution of any Neotropical deer species. This species occupies fragmented landscapes and is threatened by human encroachment, poaching, and predation by dogs, and based on our findings we recommend policy intervention for conservation planning of the Ombrophilous Dense Forest.

Cost-effective scat-detection dogs: unleashing a powerful new tool for international mammalian conservation biology

Recently, detection dogs have been utilized to collect fecal samples from cryptic and rare mammals. Despite the great promise of this technique for conservation biology, its broader application has been limited by the high cost (tens to hundreds of thousands of dollars) and logistical challenges of employing a scat-detection dog team while conducting international, collaborative research. Through an international collaboration of primatologists and the Chinese Ministry of Public Security, we trained and used a detection dog to find scat from three species of unhabituated, free-ranging primates, for less than $3,000. We collected 137 non-human primate fecal samples that we confirmed by sequencing taxonomically informative genetic markers. Our detection dog team had a 92% accuracy rate, significantly outperforming our human-only team. Our results demonstrate that detection dogs can locate fecal samples from unhabituated primates with variable diets, locomotion, and grouping patterns, despite challenging field conditions. We provide a model for in-country training, while also building local capacity for conservation and genetic monitoring. Unlike previous efforts, our approach will allow for the wide adoption of scat-detection dogs in international conservation biology.

A Comparative Analysis of Genetic Diversity and Structure in Jaguars (Panthera onca), Pumas (Puma concolor), and Ocelots (Leopardus pardalis) in Fragmented Landscapes of a Critical Mesoamerican Linkage Zone

With increasing anthropogenic impact and landscape change, terrestrial carnivore populations are becoming more fragmented. Thus, it is crucial to genetically monitor wild carnivores and quantify changes in genetic diversity and gene flow in response to these threats. This study combined the use of scat detector dogs and molecular scatology to conduct the first genetic study on wild populations of multiple Neotropical felids coexisting across a fragmented landscape in Belize, Central America. We analyzed data from 14 polymorphic microsatellite loci in 1053 scat samples collected from wild jaguars (Panthera onca), pumas (Puma concolor), and ocelots (Leopardus pardalis). We assessed levels of genetic diversity, defined potential genetic clusters, and examined gene flow for the three target species on a countrywide scale using a combination of individual- and population-based analyses. Wild felids in Belize showed moderate levels of genetic variation, with jaguars having the lowest diversity estimates (HE = 0.57 ± 0.02; AR = 3.36 ± 0.09), followed by pumas (HE = 0.57 ± 0.08; AR = 4.20 ± 0.16), and ocelots (HE = 0.63 ± 0.03; AR = 4.16 ± 0.08). We observed low to moderate levels of genetic differentiation for all three target species, with jaguars showing the lowest degree of genetic subdivision across the country, followed by ocelots and pumas. Although levels of genetic diversity and gene flow were still fairly high, we detected evidence of fine-scale genetic subdivision, indicating that levels of genetic connectivity for wild felids in Belize are likely to decrease if habitat loss and fragmentation continue at the current rate. Our study demonstrates the value of understanding fine-scale patterns of gene flow in multiple co-occurring felid species of conservation concern, which is vital for wildlife movement corridor planning and prioritizing future conservation and management efforts within human-impacted landscapes.

Evaluation of Scat Deposition Transects versus Radio Telemetry for Developing a Species Distribution Model for a Rare Desert Carnivore, the Kit Fox

Development and evaluation of noninvasive methods for monitoring species distribution and abundance is a growing area of ecological research. While noninvasive methods have the advantage of reduced risk of negative factors associated with capture, comparisons to methods using more traditional invasive sampling is lacking. Historically kit foxes (Vulpes macrotis) occupied the desert and semi-arid regions of southwestern North America. Once the most abundant carnivore in the Great Basin Desert of Utah, the species is now considered rare. In recent decades, attempts have been made to model the environmental variables influencing kit fox distribution. Using noninvasive scat deposition surveys for determination of kit fox presence, we modeled resource selection functions to predict kit fox distribution using three popular techniques (Maxent, fixed-effects, and mixed-effects generalized linear models) and compared these with similar models developed from invasive sampling (telemetry locations from radio-collared foxes). Resource selection functions were developed using a combination of landscape variables including elevation, slope, aspect, vegetation height, and soil type. All models were tested against subsequent scat collections as a method of model validation. We demonstrate the importance of comparing multiple model types for development of resource selection functions used to predict a species distribution, and evaluating the importance of environmental variables on species distribution. All models we examined showed a large effect of elevation on kit fox presence, followed by slope and vegetation height. However, the invasive sampling method (i.e., radio-telemetry) appeared to be better at determining resource selection, and therefore may be more robust in predicting kit fox distribution. In contrast, the distribution maps created from the noninvasive sampling (i.e., scat transects) were significantly different than the invasive method, thus scat transects may be appropriate when used in an occupancy framework to predict species distribution. We concluded that while scat deposition transects may be useful for monitoring kit fox abundance and possibly occupancy, they do not appear to be appropriate for determining resource selection. On our study area, scat transects were biased to roadways, while data collected using radio-telemetry was dictated by movements of the kit foxes themselves. We recommend that future studies applying noninvasive scat sampling should consider a more robust random sampling design across the landscape (e.g., random transects or more complete road coverage) that would then provide a more accurate and unbiased depiction of resource selection useful to predict kit fox distribution.

Using detection dogs and genetic analyses of scat to expand knowledge and assist felid conservation in Misiones, Argentina

Many carnivores require large ranges to meet their ecological and energetic needs; however, anthropogenic changes threaten species and their habitats. Camera traps have been used to effectively collect data on carnivores in a variety of habitat types; however, a single survey effort is typically limited to species that have similar body size, habitat use and movement patterns, and individual identification of animals is not always possible. We evaluated whether scat detection dogs could effectively survey for 4 wide-ranging felids that vary in these characteristics: jaguars (Panthera onca), pumas (Puma concolor), ocelots (Leopardus pardalis) and oncillas (Leopardus tigrinus). From June to October 2009 and May to August 2011, a detection dog-handler team detected 588 scats, from which 176 unique genotypes were detected. We assigned sex to 84.7% of the genotyped scats and identified 55 individuals multiple times. The effectiveness of these noninvasive techniques (detection dogs and genetic analyses of scat) not only opens the door for additional studies in areas that were previously difficult or impossible with standard survey techniques, but also provides conservationists with a set of tools that overcome some of the limitations associated with the use of camera traps alone.

Detection dog efficacy for collecting faecal samples from the critically endangered Cross River gorilla (Gorilla gorilla diehli) for genetic censusing

Population estimates using genetic capture-recapture methods from non-invasively collected wildlife samples are more accurate and precise than those obtained from traditional methods when detection and resampling rates are high. Recently, detection dogs have been increasingly used to find elusive species and their by-products. Here we compared the effectiveness of dog- and human-directed searches for Cross River gorilla (Gorilla gorilla diehli) faeces at two sites. The critically endangered Cross River gorilla inhabits a region of high biodiversity and endemism on the border between Nigeria and Cameroon. The rugged highland terrain and their cryptic behaviour make them difficult to study and a precise population size for the subspecies is still lacking. Dog-directed surveys located more fresh faeces with less bias than human-directed survey teams. This produced a more reliable population estimate, although of modest precision given the small scale of this pilot study. Unfortunately, the considerable costs associated with use of the United States-based detection dog teams make the use of these teams financially unfeasible for a larger, more comprehensive survey. To realize the full potential of dog-directed surveys and increase cost-effectiveness, we recommend basing dog-detection teams in the countries where they will operate and expanding the targets the dogs are trained to detect.

Resistance to antibiotics of clinical relevance in the fecal microbiota of Mexican wildlife

There are a growing number of reports of antibiotic resistance (ATBR) in bacteria living in wildlife. This is a cause for concern as ATBR in wildlife represents a potential public health threat. However, little is known about the factors that might determine the presence, abundance and dispersion of ATBR bacteria in wildlife. Here, we used culture and molecular methods to assess ATBR in bacteria in fecal samples from howler monkeys (Alouatta palliata), spider monkeys (Ateles geoffroyi), tapirs (Tapirus bairdii) and felids (jaguars, Panthera onca; pumas, Puma concolor; jaguarundis, Puma yagouaroundi; and ocelots, Leopardus pardalis) living freely in two regions of the Mexican state of Veracruz under different degrees of human influence. Overall, our study shows that ATBR is commonplace in bacteria isolated from wildlife in southeast Mexico. Most of the resistances were towards old and naturally occurring antibiotics, but we also observed resistances of potential clinical significance. We found that proximity to humans positively affected the presence of ATBR and that ATBR was higher in terrestrial than arboreal species. We also found evidence suggesting different terrestrial and aerial routes for the transmission of ATBR between humans and wildlife. The prevalence and potential ATBR transfer mechanisms between humans and wildlife observed in this study highlight the need for further studies to identify the factors that might determine ATBR presence, abundance and distribution.

The dispersion and detection patterns of mtDNA-assigned red fox Vulpes vulpes scats in Tasmania are anomalous

Models used for resource allocation in eradication programmes must be based on replicated data of known quality and have proven predictive accuracy, or they may provide a false indication of species presence and/or distribution. In the absence of data corroborating the presence of extant foxes Vulpes vulpes in Tasmania, a habitat-specific model based upon mtDNA data (Sarre et al. 2012. Journal Applied Ecology, 50, 459-468) implied that foxes were widespread. Overall, 61 of 9940 (0·6%) surveyed scats were assigned as mtDNA fox positive by the fox eradication programme (FEP). We investigated the spatiotemporal distribution of the 61 mtDNA-assigned fox scats and modelled the probability of replicating scat detection in independent surveys using detection dogs based upon empirically derived probabilities of scat detection success obtained by the FEP using imported fox scats. In a prior mainland study, fox genotypes were recurrently detected in a consecutive four-day pool of scats. In Tasmania, only three contemporaneously collected scat pairs of unknown genotype were detected by the FEP within an area corresponding to a conservatively large mainland fox home range (639 ha) in a decade. Nearest neighbour pairs were widely spaced (mean = 7·0 km; circular area = 153 km2) and generated after a mean of 281 days. The majority of assigned mtDNA positive scats were found in urban and peri-urban environments corresponding to small mainland fox home ranges (30-45 ha) that imply higher scat density and more certain replication. Using the lowest empirically determined scat detection success for dogs, the failure to replicate fox scat detection on 34 of 36 occasions in a large (639 ha) home range is highly improbable (P = 0·00001) and suggestive of Type I error. Synthesis and applications. Type I error, which may have various sources, should be considered when scat mtDNA data are few, accumulated over many years, uncorroborated by observations of extant specimens, inadequately replicated in independent surveys within an expected spatiotemporal scale and reported in geographically isolated environments unlikely to have been colonized.

Convergence of gut microbiomes in myrmecophagous mammals

Mammals have diversified into many dietary niches. Specialized myrmecophagous (ant- and termite-eating) placental mammals represent a textbook example of evolutionary convergence driven by extreme diet specialization. Armadillos, anteaters, aardvarks, pangolins and aardwolves thus provide a model system for understanding the potential role of gut microbiota in the convergent adaptation to myrmecophagy. Here, we expand upon previous mammalian gut microbiome studies by using high-throughput barcoded Illumina sequencing of the 16S rRNA gene to characterize the composition of gut microbiota in 15 species representing all placental myrmecophagous lineages and their close relatives from zoo- and field-collected samples. We confirm that both diet and phylogeny drive the evolution of mammalian gut microbiota, with cases of convergence in global composition, but also examples of phylogenetic inertia. Our results reveal specialized placental myrmecophages as a spectacular case of large-scale convergence in gut microbiome composition. Indeed, neighbour-net networks and beta-diversity plots based on UniFrac distances show significant clustering of myrmecophagous species (anteaters, aardvarks and aardwolves), even though they belong to phylogenetically distant lineages representing different orders. The aardwolf, which diverged from carnivorous hyenas only in the last 10 million years, experienced a convergent shift in the composition of its gut microbiome to become more similar to other myrmecophages. These results confirm diet adaptation to be a major driving factor of convergence in gut microbiome composition over evolutionary timescales. This study sets the scene for future metagenomic studies aiming at evaluating potential convergence in functional gene content in the microbiomes of specialized mammalian myrmecophages.

Using detection dogs to conduct simultaneous surveys of northern spotted (Strix occidentalis caurina) and barred owls (Strix varia)

State and federal actions to conserve northern spotted owl (Strix occidentalis caurina) habitat are largely initiated by establishing habitat occupancy. Northern spotted owl occupancy is typically assessed by eliciting their response to simulated conspecific vocalizations. However, proximity of barred owls (Strix varia)–a significant threat to northern spotted owls–can suppress northern spotted owl responsiveness to vocalization surveys and hence their probability of detection. We developed a survey method to simultaneously detect both species that does not require vocalization. Detection dogs (Canis familiaris) located owl pellets accumulated under roost sites, within search areas selected using habitat association maps. We compared success of detection dog surveys to vocalization surveys slightly modified from the U.S. Fish and Wildlife Service’s Draft 2010 Survey Protocol. Seventeen 2 km ×2 km polygons were each surveyed multiple times in an area where northern spotted owls were known to nest prior to 1997 and barred owl density was thought to be low. Mitochondrial DNA was used to confirm species from pellets detected by dogs. Spotted owl and barred owl detection probabilities were significantly higher for dog than vocalization surveys. For spotted owls, this difference increased with number of site visits. Cumulative detection probabilities of northern spotted owls were 29% after session 1, 62% after session 2, and 87% after session 3 for dog surveys, compared to 25% after session 1, increasing to 59% by session 6 for vocalization surveys. Mean detection probability for barred owls was 20.1% for dog surveys and 7.3% for vocal surveys. Results suggest that detection dog surveys can complement vocalization surveys by providing a reliable method for establishing occupancy of both northern spotted and barred owl without requiring owl vocalization. This helps meet objectives of Recovery Actions 24 and 25 of the Revised Recovery Plan for the Northern Spotted Owl.

Prey preference of snow leopard (Panthera uncia) in South Gobi, Mongolia

Accurate information about the diet of large carnivores that are elusive and inhabit inaccessible terrain, is required to properly design conservation strategies. Predation on livestock and retaliatory killing of predators have become serious issues throughout the range of the snow leopard. Several feeding ecology studies of snow leopards have been conducted using classical approaches. These techniques have inherent limitations in their ability to properly identify both snow leopard feces and prey taxa. To examine the frequency of livestock prey and nearly-threatened argali in the diet of the snow leopard, we employed the recently developed DNA-based diet approach to study a snow leopard population located in the Tost Mountains, South Gobi, Mongolia. After DNA was extracted from the feces, a region of ∼100 bp long from mitochondrial 12S rRNA gene was amplified, making use of universal primers for vertebrates and a blocking oligonucleotide specific to snow leopard DNA. The amplicons were then sequenced using a next-generation sequencing platform. We observed a total of five different prey items from 81 fecal samples. Siberian ibex predominated the diet (in 70.4% of the feces), followed by domestic goat (17.3%) and argali sheep (8.6%). The major part of the diet was comprised of large ungulates (in 98.8% of the feces) including wild ungulates (79%) and domestic livestock (19.7%). The findings of the present study will help to understand the feeding ecology of the snow leopard, as well as to address the conservation and management issues pertaining to this wild cat.

Resource selection and its implications for wide-ranging mammals of the brazilian cerrado

Conserving animals beyond protected areas is critical because even the largest reserves may be too small to maintain viable populations for many wide-ranging species. Identification of landscape features that will promote persistence of a diverse array of species is a high priority, particularly, for protected areas that reside in regions of otherwise extensive habitat loss. This is the case for Emas National Park, a small but important protected area located in the Brazilian Cerrado, the world's most biologically diverse savanna. Emas Park is a large-mammal global conservation priority area but is too small to protect wide-ranging mammals for the long-term and conserving these populations will depend on the landscape surrounding the park. We employed novel, noninvasive methods to determine the relative importance of resources found within the park, as well as identify landscape features that promote persistence of wide-ranging mammals outside reserve borders. We used scat detection dogs to survey for five large mammals of conservation concern: giant armadillo (Priodontes maximus), giant anteater (Myrmecophaga tridactyla), maned wolf (Chrysocyon brachyurus), jaguar (Panthera onca), and puma (Puma concolor). We estimated resource selection probability functions for each species from 1,572 scat locations and 434 giant armadillo burrow locations. Results indicate that giant armadillos and jaguars are highly selective of natural habitats, which makes both species sensitive to landscape change from agricultural development. Due to the high amount of such development outside of the Emas Park boundary, the park provides rare resource conditions that are particularly important for these two species. We also reveal that both woodland and forest vegetation remnants enable use of the agricultural landscape as a whole for maned wolves, pumas, and giant anteaters. We identify those features and their landscape compositions that should be prioritized for conservation, arguing that a multi-faceted approach is required to protect these species.

Successful carnivore identification with faecal DNA across a fragmented Amazonian landscape

The use of scat surveys to obtain DNA has been well documented in temperate areas, where DNA preservation may be more effective than in tropical forests. Samples obtained in the tropics are often exposed to high humidity, warm temperatures, frequent rain and intense sunlight, all of which can rapidly degrade DNA. Despite these potential problems, we demonstrate successful mtDNA amplification and sequencing for faeces of carnivores collected in tropical conditions and quantify how sample condition and environmental variables influence the success of PCR amplification and species identification. Additionally, the feasibility of genotyping nuclear microsatellites from jaguar (Panthera onca) faeces was investigated. From October 2007 to December 2008, 93 faecal samples were collected in the southern Brazilian Amazon. A total of eight carnivore species was successfully identified from 71% of all samples obtained. Information theoretic analysis revealed that the number of PCR attempts before a successful sequence was an important negative predictor across all three responses (success of species identification, success of species identification from the first sequence and PCR amplification success), whereas the relative importance of the other three predictors (sample condition, season and distance from forest edge) varied between the three responses. Nuclear microsatellite amplification from jaguar faeces had lower success rates (15-44%) compared with those of the mtDNA marker. Our results show that DNA obtained from faecal samples works efficiently for carnivore species identification in the Amazon forest and also shows potential for nuclear DNA analysis, thus providing a valuable tool for genetic, ecological and conservation studies.