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As global large carnivore populations continue to decline due to human actions, maintaining viable populations beyond protected area (PA) borders is critical. African lions ( Panthera leo ) ranging beyond PA borders regularly prey on domestic livestock causing humans to retaliate or even preemptively kill lions to minimize impacts of lost livestock. To understand how lions navigate high-conflict areas in human-dominated landscapes, lions were observed and monitored in the eastern Panhandle of the Okavango Delta between October 2014 and December 2016, and five lions were fitted with GPS satellite collars from August 2015 to December 2016. Lion prides and coalitions were small, with all prides having four or fewer females and all coalitions having two or fewer males. Home range size varied between the sexes but was not statistically different (males: x ¯ = 584 km 2 , n = 3; females: x ¯ = 319 km 2 , n = 2). There was considerable spatial overlap in home ranges as nonassociating, neighboring collared individuals utilized high levels of shared space (female-female overlap = 152 km 2 , representing 41-56% of respective home ranges; male-male overlap = 125-132 km 2 , representing 16-31% of respective home ranges). However, neighboring lions varied use of shared space temporally as evidenced by low coefficients of association (< 0.08), avoiding potentially costly interactions with neighboring individuals. Highest levels of overlap occurred during the wet and early dry seasons when flood waters minimized the amount of available land area. All collared individuals minimized time in close proximity (< 3 km) to human habitation, but some individuals were able to rely heavily on areas where unmonitored livestock grazed. While most lions exist within PAs, anthropogenic impacts beyond PA boundaries can impact critical populations within PAs. Studying systems beyond park boundaries with high levels of human-lion conflict while also establishing conservation programs that account for both ecological and sociocultural dimensions will better aid lion conservation efforts moving forward., Competing Interests: The authors declare that they have no conflict of interest., (© The Author(s) 2023. Published by Oxford University Press on behalf of the American Society of Mammalogists.)

The Thung Yai Naresuan (East) Wildlife Sanctuary (TYNE), in the core area of the Western Forest Complex of Thailand, harbors a diverse assemblage of wildlife, and the region has become globally significant for mammal conservation. From April 2010 to January 2012, 106 camera traps were set, and, in 1817 trap-nights, registered 1821 independent records of 32 mammal species. Of the 17 IUCN-listed (from Near Threatened to Critically Endangered) mammal species recorded, 5 species listed as endangered or critically endangered included the Asiatic elephant ( Elephas maximus ), tiger ( Panthera tigris ), Malayan tapir ( Tapirus indicus ), dhole ( Cuon alpinus ), and Sunda pangolin ( Manis javanica ). The northern red muntjac ( Muntiacus vaginalis ), large Indian civet ( Viverra zibetha ), Malayan porcupine ( Hystrix brachyuran ), and sambar deer ( Cervus unicolor ) were the most frequently recorded species (10-22 photos/100 trap-nights), representing 62% of all independent records, while the golden jackal ( Canis aureus ), clouded leopard ( Neofelis nebulosa ), marbled cat ( Pardofelis marmorata ), and Sunda pangolin were the least photographed (<0.1/100 trap-nights). Species accumulation curves indicated that the number of camera trap locations needed to record 90% of taxa recorded varied from 26 sites for herbivores to 67 sites for all mammals. TYNE holds a rich community of mammals, but some differences in photo-rates from an adjacent sanctuary and comparisons with other research on local mammals suggest that some species are rare and some are missed because of the limitations of our technique. We also conclude that the management and conservation plan, which involves the exclusion of human activities from some protected areas and strict protection efforts in the sanctuaries, is still suitable for providing key habitats for endangered wildlife populations, and that augmented and regular survey efforts will help in this endeavor.

Regular evaluation of jaguar ( Panthera onca ) population status is an important part of conservation decision-making. Currently, camera trapping has become the standard method used to estimate jaguar abundance and demographic parameters, though evidence has shown the potential for sex ratio biases and density overestimates. In this study, we used camera trap data combined with satellite telemetry data from one female jaguar to estimate jaguar population density in the dry forest of Santa Rosa National Park in the Guanacaste Conservation Area of northwestern Costa Rica. We analyzed camera trap data collected from June 2016 to June 2017 using spatial capture-recapture methods to estimate jaguar density. In total, 19 individual jaguars were detected (11 males; 8 females) with a resulting estimated population density of 2.6 females (95% [CI] 1.7-4.0) and 5.0 male (95% [CI] 3.4-7.4) per 100 km 2 . Based on telemetry and camera trap data, camera placement might bias individual detections by sex and thus overall density estimates. We recommend population assessments be made at several consecutive 3-month intervals, that larger areas be covered so as not to restrict surveys to one or two individual home ranges, as in our case, and to carry out long-term camera monitoring programs instead of short-term studies to better understand the local population, using auxiliary telemetry data to adjust field designs and density estimations to improve support for jaguar conservation strategies.

Prey abundance and prey vulnerability vary across space and time, but we know little about how they mediate predator-prey interactions and predator foraging tactics. To evaluate the interplay between prey abundance, prey vulnerability and predator space use, we examined patterns of black bear (Ursus americanus) predation of caribou (Rangifer tarandus) neonates in Newfoundland, Canada using data from 317 collared individuals (9 bears, 34 adult female caribou, 274 caribou calves). During the caribou calving season, we predicted that landscape features would influence calf vulnerability to bear predation, and that bears would actively hunt calves by selecting areas associated with increased calf vulnerability. Further, we hypothesized that bears would dynamically adjust their foraging tactics in response to spatiotemporal changes in calf abundance and vulnerability (collectively, calf availability). Accordingly, we expected bears to actively hunt calves when they were most abundant and vulnerable, but switch to foraging on other resources as calf availability declined. As predicted, landscape heterogeneity influenced risk of mortality, and bears displayed the strongest selection for areas where they were most likely to kill calves, which suggested they were actively hunting caribou. Initially, the per-capita rate at which bears killed calves followed a type-I functional response, but as the calving season progressed and calf vulnerability declined, kill rates dissociated from calf abundance. In support of our hypothesis, bears adjusted their foraging tactics when they were less efficient at catching calves, highlighting the influence that predation phenology may have on predator space use. Contrary to our expectations, however, bears appeared to continue to hunt caribou as calf availability declined, but switched from a tactic of selecting areas of increased calf vulnerability to a tactic that maximized encounter rates with calves. Our results reveal that generalist predators can dynamically adjust their foraging tactics over short time-scales in response to changing prey abundance and vulnerability. Further, they demonstrate the utility of integrating temporal dynamics of prey availability into investigations of predator-prey interactions, and move towards a mechanistic understanding of the dynamic foraging tactics of a large omnivore., (© 2018 The Authors. Journal of Animal Ecology © 2018 British Ecological Society.)

Anthropogenic disturbances have altered species' distributions potentially impacting interspecific interactions. Interference competition is when one species denies a competing species access to a resource. One mechanism of interference competition is aggression, which can result in altered space-use of a subordinate species due to the threat of harm, otherwise known as a 'landscape of fear'. Alternatively, subordinates might outcompete dominant species in resource-poor environments via a superior ability to extract resources. Our goal was to evaluate spatial predictions of the 'landscape of fear' hypothesis for a carnivore guild in Newfoundland, Canada, where coyotes recently immigrated. Native Newfoundland carnivores include red foxes, Canada lynx, and black bears. We predicted foxes and lynx would avoid coyotes because of their larger size and similar dietary niches. We used scat-detecting dogs and genetic techniques to locate and identify predator scats. We then built resource selection functions and tested for avoidance by incorporating predicted values of selection for the alternative species into the best supported models of each species. We found multiple negative relationships, but notably did not find avoidance by foxes of areas selected by coyotes. While we did find that lynx avoided coyotes, we also found a reciprocal relationship. The observed patterns suggest spatial partitioning and not coyote avoidance, although avoidance could still be occurring at different spatial or temporal scales. Furthermore, Newfoundland's harsh climate and poor soils may swing the pendulum of interspecific interactions from interference competition to exploitative competition, where subordinates outcompete dominant competitors through a superior ability to extract resources.

In the 200 years since the Sumatran rhinoceros was first scientifically described (Fisher 1814), the range of the species has contracted from a broad region in Southeast Asia to three areas on the island of Sumatra and one in Kalimantan, Indonesia. Assessing population and spatial distribution of this very rare species is challenging because of their elusiveness and very low population number. Using an occupancy model with spatial dependency, we assessed the fraction of the total landscape occupied by Sumatran rhinos over a 30,345-km2 survey area and the effects of covariates in the areas where they are known to occur. In the Leuser Landscape (surveyed in 2007), the model averaging result of conditional occupancy estimate was ψ(SE[ψ]) = 0.151(0.109) or 2,371.47 km2, and the model averaging result of replicated level detection probability p(SE[p]) = 0.252(0.267); in Way Kambas National Park--2008: ψ(SE[ψ]) = 0.468(0.165) or 634.18 km2, and p(SE[p]) = 0.138(0.571); and in Bukit Barisan Selatan National Park--2010: ψ(SE[ψ]) = 0.322(0.049) or 819.67 km2, and p(SE[p]) = 0.365(0.42). In the Leuser Landscape, rhino occurrence was positively associated with primary dry land forest and rivers, and negatively associated with the presence of a road. In Way Kambas, occurrence was negatively associated with the presence of a road. In Bukit Barisan Selatan, occurrence was negatively associated with presence of primary dryland forest and rivers. Using the probabilities of site occupancy, we developed spatially explicit maps that can be used to outline intensive protection zones for in-situ conservation efforts, and provide a detailed assessment of conserving Sumatran rhinos in the wild. We summarize our core recommendation in four points: consolidate small population, strong protection, determine the percentage of breeding females, and recognize the cost of doing nothing. To reduce the probability of poaching, here we present only the randomized location of site level occupancy in our result while retaining the overall estimation of occupancy for a given area. ψ

Monitoring large carnivores is difficult because of intrinsically low densities and can be dangerous if physical capture is required. Noninvasive genetic sampling (NGS) is a safe and cost-effective alternative to physical capture. We evaluated the utility of two NGS methods (scat detection dogs and hair sampling) to obtain genetic samples for abundance estimation of coyotes, black bears and Canada lynx in three areas of Newfoundland, Canada. We calculated abundance estimates using program capwire, compared sampling costs, and the cost/sample for each method relative to species and study site, and performed simulations to determine the sampling intensity necessary to achieve abundance estimates with coefficients of variation (CV) of <10%. Scat sampling was effective for both coyotes and bears and hair snags effectively sampled bears in two of three study sites. Rub pads were ineffective in sampling coyotes and lynx. The precision of abundance estimates was dependent upon the number of captures/individual. Our simulations suggested that ~3.4 captures/individual will result in a < 10% CV for abundance estimates when populations are small (23-39), but fewer captures/individual may be sufficient for larger populations. We found scat sampling was more cost-effective for sampling multiple species, but suggest that hair sampling may be less expensive at study sites with limited road access for bears. Given the dependence of sampling scheme on species and study site, the optimal sampling scheme is likely to be study-specific warranting pilot studies in most circumstances., (© 2015 John Wiley & Sons Ltd.)

Increasingly, habitat fragmentation caused by agricultural and human development has forced Sumatran elephants into relatively small areas, but there is little information on how elephants use these areas and thus, how habitats can be managed to sustain elephants in the future. Using a Global Positioning System (GPS) collar and a land cover map developed from TM imagery, we identified the habitats used by a wild adult female elephant (Elephas maximus sumatranus) in the Seblat Elephant Conservation Center, Bengkulu Province, Sumatra during 2007-2008. The marked elephant (and presumably her 40-60 herd mates) used a home range that contained more than expected medium canopy and open canopy land cover. Further, within the home range, closed canopy forests were used more during the day than at night. When elephants were in closed canopy forests they were most often near the forest edge vs. in the forest interior. Effective elephant conservation strategies in Sumatra need to focus on forest restoration of cleared areas and providing a forest matrix that includes various canopy types.

The roles of dispersal and population dynamics in determining species' range boundaries recently have received theoretical attention but little empirical work. Here we provide data on survival, reproduction, and movement for a Virginia opossum (Didelphis virginiana) population at a local distributional edge in central Massachusetts (USA). Most juvenile females that apparently exploited anthropogenic resources survived their first winter, whereas those using adjacent natural resources died of starvation. In spring, adult females recolonized natural areas. A life-table model suggests that a population exploiting anthropogenic resources may grow, acting as source to a geographically interlaced sink of opossums using only natural resources, and also providing emigrants for further range expansion to new human-dominated landscapes. In a geographical model, this source-sink dynamic is consistent with the local distribution identified through road-kill surveys. The Virginia opossum's exploitation of human resources likely ameliorates energetically restrictive winters and may explain both their local distribution and their northward expansion in unsuitable natural climatic regimes. Landscape heterogeneity, such as created by urbanization, may result in source-sink dynamics at highly localized scales. Differential fitness and individual dispersal movements within local populations are key to generating regional distributions, and thus species ranges, that exceed expectations.

Roads present formidable barriers to dispersal. We examine movements of two highly mobile carnivores across the Ventura Freeway near Los Angeles, one of the busiest highways in the United States. The two species, bobcats and coyotes, can disappear from habitats isolated and fragmented by roads, and their ability to disperse across the Ventura Freeway tests the limits of vertebrates to overcome anthropogenic obstacles. We combine radio-telemetry data and genetically based assignments to identify individuals that have crossed the freeway. Although the freeway is a significant barrier to dispersal, we find that carnivores can cross the freeway and that 5-32% of sampled carnivores crossed over a 7-year period. However, despite moderate levels of migration, populations on either side of the freeway are genetically differentiated, and coalescent modelling shows their genetic isolation is consistent with a migration fraction less than 0.5% per generation. These results imply that individuals that cross the freeway rarely reproduce. Highways and development impose artificial home range boundaries on territorial and reproductive individuals and hence decrease genetically effective migration. Further, territory pile-up at freeway boundaries may decrease reproductive opportunities for dispersing individuals that do manage to cross. Consequently, freeways are filters favouring dispersing individuals that add to the migration rate but little to gene flow. Our results demonstrate that freeways can restrict gene flow even in wide-ranging species and suggest that for territorial animals, migration levels across anthropogenic barriers need to be an order of magnitude larger than commonly assumed to counteract genetic differentiation.

We examined the relative roles of dominance in agonistic interactions and energetic constraints related to body size in determining local abundances of coyotes (Canis latrans, 8-20 kg), gray foxes (Urocyon cinereoargenteus, 3-5 kg) and bobcats (Felis rufus, 5-15 kg) at three study sites (hereafter referred to as NP, CP, and SP) in the Santa Monica Mountains of California. We hypothesized that the largest and behaviorally dominant species, the coyote, would exploit a wider range of resources (i.e., a higher number of habitat and/or food types) and, consequently, would occur in higher density than the other two carnivores. We evaluated our hypotheses by quantifying their diets, food overlap, habitat-specific abundances, as well as their overall relative abundance at the three study sites. We identified behavioral dominance of coyotes over foxes and bobcats in Santa Monica because 7 of 12 recorded gray fox deaths and 2 of 5 recorded bobcat deaths were due to coyote predation, and no coyotes died as a result of their interactions with bobcats or foxes. Coyotes and bobcats were present in a variety of habitats types (8 out of 9), including both open and brushy habitats, whereas gray foxes were chiefly restricted to brushy habitats. There was a negative relationship between the abundances of coyotes and gray foxes (P=0.020) across habitats, suggesting that foxes avoided habitats of high coyote predation risk. Coyote abundance was low in NP, high in CP, and intermediate in SP. Bobcat abundance changed little across study sites, and gray foxes were very abundant in NP, absent in CP, and scarce in SP; this suggests a negative relationship between coyote and fox abundances across study sites, as well. Bobcats were solely carnivorous, relying on small mammals (lagomorphs and rodents) throughout the year and at all three sites. Coyotes and gray foxes also relied on small mammals year-round at all sites, though they also ate significant amounts of fruit. Though there were strong overall interspecific differences in food habits of carnivores (P<0.0001), average seasonal food overlaps were high due to the importance of small mammals in all carnivore diets [bobcat-gray fox: 0.79±0.09 (SD), n=4; bobcat-coyote: 0.69±0.16, n=6; coyote-gray fox: 0.52±0.05, n=4]. As hypothesized, coyotes used more food types and more habitat types than did bobcats and gray foxes and, overall, coyotes were the most abundant of the three species and ranged more widely than did gray foxes. We propose that coyotes limit the number and distribution of gray foxes in Santa Monica Mountains, and that those two carnivores exemplified a case in which the relationship between their body size and local abundance is governed by competitive dominance of the largest species rather than by energetic equivalences. However, in the case of the intermediate-sized bobcat no such a pattern emerged, likely due to rarity or inconsistency of agonistic interactions and/or behavioral avoidance of encounters by subordinate species.

Large carnivores are of vital importance to the stability and integrity of most ecosystems, but recent declines in free-ranging populations have highlighted the potentially devastating effect of infectious diseases on their conservation. We reviewed the literature on infectious diseases of 34 large (maximum body mass of adults >20 kg) terrestrial carnivore species, 18 of which are considered to be threatened in the wild, and examined reports of antibody prevalence (seroprevalence) and cases of infection, mortality and population decline. Of 52 diseases examined, 44% were viral, 31% bacterial and the remainder were protozoal or fungal. Many infections were endemic in carnivores and/or infected multiple taxonomic families, with the majority probably occurring via inhalation or ingestion. Most disease studies consisted of serological surveys for disease antibodies, and antibody detection tended to be widespread implying that exposure to micro-organisms was common. Seroprevalence was higher in tropical than temperate areas, and marginally higher for infections known to occur in multiple carnivore groups. Confirmation of active infection via micro-organism recovery was less common for ursids than other taxonomic groups. Published descriptions of disease-induced population decline or extinction were rare, and most outbreaks were allegedly the result of direct transmission of rabies or canine distemper virus (CDV) from abundant carnivore species to less-common large carnivores. We conclude that the threat of disease epidemics in large carnivores may be serious if otherwise lethal infections are endemic in reservoir hosts and transmitted horizontally among taxa. To prevent or mitigate future population declines, research efforts should be aimed at identifying both the diseases of potential importance to large carnivores and the ecological conditions associated with their spread and severity.