Do coyotes Canis latrans influence occupancy of prey in suburban forest fragments?

Diel activity structures the occurrence of a mammal community in a human-dominated landscape

Anthropogenic developments alter the environment and resources available to wildlife communities. In response to these real or perceived threats from this development, species may adjust their spatial occurrence. Additionally, wildlife species may adjust when in diel time (24-h light-dark cycle) they occupy sites on the landscape to adapt to changing conditions. However, many wildlife studies only focus on where a species does and does not occur, ignoring how species may shift their diel activity at sites to mitigate threats. We used a multi-state diel occupancy modeling framework to investigate how a community of mammals (mesocarnivores, urban-adapted omnivores, and herbivore/small mammals) respond to differing levels of anthropogenic development and forest cover across two climatic seasons. We collected camera trap data at 240 survey locations across the summer and winter of 2021-2022. We modeled multi-state diel occupancy for 14 mammal species with extent of development/forest and season hypothesized to influence diel occupancy and season hypothesized to influence the probability of detection. We found that all species displayed heterogeneity in both diel occupancy and detection either by extent of development/forest and or season. Within the mesocarnivore species group, coyote and red fox were less sensitive to development and had higher occupancy probability at these sites in general but used them more during the night, while more sensitive mesocarnivores including fisher and bobcat occupied the day state only when there was increasing forest cover. Our results highlight the importance of incorporating diel activity in habitat modeling to better understand the relationship between a species and its landscape, particularly in a region that is vulnerable to increased anthropogenic pressure.

Factors affecting the occupancy of sloth bear and its detection probability in Parsa-Koshi Complex, Nepal

Understanding factors associated with coexistence of human and wildlife in human-dominated landscapes is crucial for effective species conservation. Among the wildlife species, the sloth bears Melursus ursinus are found both inside and outside the protected areas of Nepal, and with increasing cases of human and bear conflicts in both areas. This highlights the necessity for a comprehensive understanding of anthropogenic and ecological factors that affect the occurrence of sloth bear. The understanding of these factors is important for its coexistence and conservation in human-dominated areas through establishing management and conservation action plan. We studied the sloth bear's occupancy and their coexistence in human-dominated environments with other large predators in the Parsa-Koshi Complex of Nepal using camera traps from December 2022 to March 2023. We identified the occupancy and detection probability of the sloth bear as 0.12 and 0.31, respectively. Our analysis reveals a positive relationship between sloth bear occurrence and the presence of large predators (βpredators = 3.104 ± 0.968), such as tigers (Panthera tigris) and leopards (Panthera pardus), as well as the number of humans detected (βhuman = 1.428 ± 1.216) and canopy cover percentage (βcc = 1.002 ± 0.737). However, the number of livestock detected shows a negative interaction with the occurrence of sloth bears (βlivestock = -2.240 ± 1.467). There was insignificant interaction between sloth bear occupancy and distance to human settlements, roads, and water bodies. These findings underscore the complex dynamics between sloth bears, humans, large predators, and livestock in human-dominated landscapes. To ensure the long-term survival of sloth bear populations and promote species conservation, comprehensive conservation strategies that account for both ecological and socio-economic factors are essential.

“Ecology of fear” in ungulates: Opportunities for improving conservation

Because ungulates are important contributors to ecosystem function, understanding the “ecology of fear” could be important to the conservation of ecosystems. Although studying ungulate ecology of fear is common, knowledge from ungulate systems is highly contested among ecologists. Here, we review the available literature on the ecology of fear in ungulates to generalize our current knowledge and how we can leverage it for conservation. Four general focus areas emerged from the 275 papers included in our literature search (and some papers were included in multiple categories): behavioral responses to predation risk (79%), physiological responses to predation risk (15%), trophic cascades resulting from ungulate responses to predation risk (20%), and manipulation of predation risk (1%). Of papers focused on behavior, 75% were about movement and habitat selection. Studies were biased toward North America (53%), tended to be focused on elk (Cervus canadensis; 29%), and were dominated by gray wolves (40%) or humans (39%) as predators of interest. Emerging literature suggests that we can utilize predation risk for conservation with top‐down (i.e., increasing predation risk) and bottom‐up (i.e., manipulating landscape characteristics to increase risk or risk perception) approaches. It is less clear whether fear‐related changes in physiology have population‐level fitness consequences or cascading effects, which could be fruitful avenues for future research. Conflicting evidence of trait‐mediated trophic cascades might be improved with better replication across systems and accounting for confounding effects of ungulate density. Improving our understanding of mechanisms modulating the nature of trophic cascades likely is most important to ensure desirable conservation outcomes. We recommend future work embrace the complexity of natural systems by attempting to link together the focal areas of study identified herein.

Individual and Temporal Variation in Use of Residential Areas by Urban Coyotes

Coyotes (Canis latrans) have established populations in most major urban centers across North America. While the risk of attacks on humans or their pets is low, the presence of carnivores in areas with high human use has resulted in increased public concern. Having a clearer understanding of which animals are more likely to interact with humans and when interactions are more likely to occur will help mitigate human-carnivore conflicts. Despite clear broad-scale patterns of human avoidance, human-coyote interactions occur most frequently in residential areas. Our purpose was to determine if use of residential areas varied consistently across individuals or time. We used locations from GPS collars deployed on 14 coyotes in the Greater Toronto Area, Ontario, Canada from 2012 to 2017 to fit a step selection function. Average (±SE) home range size estimates were 17.3 ± 4.6 km2 for resident coyotes and 102.8 ± 32.9 km2 for non-residents. We found that coyotes used natural areas more (β = 0.07, SE = 0.02, p < 0.0001), and roads (β = −0.50, SE = 0.13, p < 0.0001) and residential areas (β = −0.79, SE = 0.21, p = 0.0001) less during the day than at night. We also found that coyotes were more likely to use residential areas in the breeding season from January to April (β = 0.69, SE = 0.20, p = 0.0007) and the pup rearing season from May to August (β = 0.54, SE = 0.13, p < 0.0001) than in the dispersal season from September to December. Lastly, we found that resident coyotes were less likely to use residential areas than non-resident coyotes (β = −1.13, SE = 0.26, p < 0.0001). As far as we are aware, our study is the first to identify the seasons when coyotes are more likely to use residential areas. The seasonal patterns in habitat use that we observed reflect patterns that have been previously reported for human-coyote conflicts. Our results demonstrate that reducing the availability of anthropogenic food sources in residential areas, particularly in the winter and spring, should be a priority for managers aiming to reduce human-coyote conflict in urban areas.

Vigilance Response of a Key Prey Species to Anthropogenic and Natural Threats in Detroit

Rapid urbanization coupled with increased human activity induces pressures that affect predator-prey relations through a suite of behavioral mechanisms, including alteration of avoidance and coexistence dynamics. Synergisms of natural and anthropogenic threats existing within urban environments exacerbate the necessity for species to differentially modify behavior to each risk. Here, we explore the behavioral response of a key prey species, cottontail rabbits (Sylvilagus floridanus), to pressures from humans, domestic dogs, and a natural predator, coyotes (Canis latrans) in a human-dominated landscape. We conducted the first camera survey in urban parks throughout Detroit, Michigan in 2017–2020 to assess vigilance response corresponding to a heterogeneous landscape created from variation in the occupancy of threats. We predicted a scaled response where cottontail rabbits would be most vigilant in areas with high coyote activity, moderately vigilant in areas with high domestic dog activity, and the least vigilant in areas of high human activity. From 8,165 independent cottontail rabbit detections in Detroit across 11,616 trap nights, one-third were classified as vigilant. We found vigilance behavior increased with coyote occupancy and in locations with significantly high domestic dog activity, but found no significant impact of human occupancy or their spatial hotspots. We also found little spatial overlap between rabbits and threats, suggesting rabbits invest more in spatial avoidance; thus, less effort is required for vigilance. Our results elucidate strategies of a prey species coping with various risks to advance our understanding of the adaptability of wildlife in urban environments. In order to promote coexistence between people and wildlife in urban greenspaces, we must understand and anticipate the ecological implications of human-induced behavioral modifications.

Thinking outside the park: recommendations for camera trapping mammal communities in the urban matrix

Urbanization is increasing globally, fragmenting habitats and prompting human–wildlife conflict. Urban wildlife research is concurrently expanding, but sampling methods are often biased towards large and intact habitats in public green spaces, neglecting the far more abundant, but degraded, habitats in the urban matrix. Here, we introduce the Five P’s of Urban Ecology—Partnerships, Planning, Placements, Public participation and Processing—as a path to overcoming the logistical barriers often associated with camera-trapping in the urban matrix. Though the Five P’s can be applied to a variety of urban sampling methods, we showcase the camera-trapping efforts of the DC Cat Count project in Washington, DC, as a case study. We compared occupancy models for eight urban mammal species using broad categorizations of land cover and local land use to determine drivers of mammal occurrence within the urban matrix as compared with urban habitat patches. Many native species maintained a strong association with large, semi-natural green spaces, but occupancy was not limited to these locations, and in some cases, the use of private yards and the built environment were not notably different. Furthermore, some species exhibited higher occupancy probabilities in developed areas over green spaces. Though seemingly intuitive, we offer advice on how to greatly reduce habitat-biased sampling methods in urban wildlife research and illustrate the importance of doing so to ensure accurate results that support the formation of effective urban planning and policy.

Behavioral Causes, Ecological Consequences, and Management Challenges Associated with Wildlife Foraging in Human-Modified Landscapes

Humans have altered up to half of the world's land surface. Wildlife living within or close to these human-modified landscapes are presented with opportunities and risks associated with feeding on human-derived foods (e.g., agricultural crops and food waste). Understanding whether and how wildlife adapts to these landscapes is a major challenge, with thousands of studies published on the topic over the past 10 years. In the present article, we build on established theoretical frameworks to understand the behavioral causes of crop and urban foraging by wildlife. We then develop and extend this framework to describe the multifaceted ecological consequences of crop and urban foraging for the individuals and populations in which they arise, with emphasis on social species for which interactions with people are, on balance, negative (commonly referred to as raiding species). Finally, we discuss the management challenges faced by urban and rural land managers, businesses, and government organizations in mitigating human-wildlife conflicts and propose ways to improve the lives of both wildlife and humans living in human-modified landscapes and to promote coexistence.

Raccoon Vigilance and Activity Patterns When Sympatric with Coyotes

Nonconsumptive effects of predators potentially have negative fitness consequences on prey species through changes in prey behavior. Coyotes (Canis latrans) recently expanded into the eastern United States, and raccoons (Procyon lotor) are a common mesocarnivore that potentially serve as competitors and food for coyotes. We used camera traps at baited sites to quantify vigilance behavior of feeding raccoons and used binomial logistic regression to analyze the effects of social and environmental factors. Additionally, we created raccoon and coyote activity patterns from the camera trap data by fitting density functions based on circular statistics and calculating the coefficient of overlap (Δ). Overall, raccoons were vigilant 46% of the time while foraging at baited sites. Raccoons were more vigilant during full moon and diurnal hours but less vigilant as group size increased and when other species were present. Raccoons and coyotes demonstrated nocturnal activity patterns, with coyotes more likely to be active during daylight hours. Overall, raccoons did not appear to exhibit high levels of vigilance. Activity pattern results provided further evidence that raccoons do not appear to fear coyotes, as both species were active at the same time and showed a high degree of overlap (Δ = 0.75) with little evidence of temporal segregation in activity. Thus, our study indicates that nonconsumptive effects of coyotes on raccoons are unlikely, which calls into question the ability of coyotes to initiate strong trophic cascades through some mesocarnivores.

The effect of camera-trap viewshed obstruction on wildlife detection: implications for inference

Abstract ContextCamera traps are one of the most popular tools used to study wildlife worldwide. Numerous recent studies have evaluated the efficiency and effectiveness of camera traps as a research tool. Nonetheless, important aspects of camera-trap methodology remain in need of critical investigation. One such issue relates to camera-trap viewshed visibility, which is often compromised in the field by physical obstructions (e.g. trees) or topography (e.g. steep slopes). The loss of visibility due to these obstructions could affect wildlife detection rates, with associated implications for study inference and management application. AimsWe aimed to determine the effect of camera-trap viewshed obstruction on wildlife detection rates for a suite of eight North American species that vary in terms of ecology, commonness and body size. MethodsWe deployed camera traps at 204 sites throughout an extensive semi-urban park system in Cleveland, Ohio, USA, from June to September 2016. At each site, we quantified camera-trap viewshed obstruction by using a cover-board design. We then modelled the effects of obstruction on wildlife detection rates for the eight focal species. Key resultsWe found that detection rates significantly decreased with an increasing viewshed obstruction for five of the eight species, including both larger and smaller mammal species (white-tailed deer, Odocoileus virginianus, and squirrels, Sciurus sp., respectively). The number of detections per week per camera decreased two- to three-fold as visibility at a camera site decreased from completely free of obstruction to mostly obstructed. ConclusionsThese results imply that wildlife detection rates are influenced by site-level viewshed obstruction for a variety of species, and sometimes considerably so. ImplicationsResearchers using camera traps should address the potential for this effect to ensure robust inference from wildlife image data. Accounting for viewshed obstruction is critical when interpreting detection rates as indices of abundance or habitat use because variation in detection rate could be an artefact of site-level viewshed obstruction rather than due to underlying ecological processes.

Projecting Mammal Distributions in Response to Future Alternative Landscapes in a Rapidly Transitioning Region

Finding balance between the needs of people and wildlife is an essential component of planning sustainable landscapes. Because mammals make up a diverse and ecologically important taxon with varying responses to human disturbance, we used representative mammal species to examine how alternative land-use policies might affect their habitats and distributions in the near future. We used wildlife detections from camera traps at 1591 locations along a large-scale urban to wild gradient in northern Virginia, to create occupancy models which determined land cover relationships and the drivers of contemporary mammal distributions. From the 15 species detected, we classified five representative species into two groups based on their responses to human development; sensitive species (American black bears and bobcats) and synanthropic species (red foxes, domestic cats, and white-tailed deer). We then used the habitat models for the representative species to predict their distributions under four future planning scenarios based on strategic versus reactive planning and high or low human population growth. The distributions of sensitive species did not shrink drastically under any scenario, whereas the distributions of synanthropic species increased in response to anthropogenic development, but the magnitude of the response varied based on the projected rate of human population growth. This is likely because most sensitive species are dependent on large, protected public lands in the region, and the majority of projected habitat losses should occur in non-protected private lands. These findings illustrate the importance of public protected lands in mitigating range loss due to land use changes, and the potential positive impact of strategic planning in further mitigating mammalian diversity loss in private lands.

Spatiotemporal habitat use by a multitrophic Alaska alpine mammal community

Evaluating sympatric habitat use of a mammal community can help determine intra- and inter-guild interactions and identify important habitats, potentially improving the management of these communities with a changing climate. Increasingly variable climatic patterns in Alaska, USA, are raising concerns of mismatched phenologies and altered ecosystem structures. We studied the occupancy of 10 mammal species over 15 months, via camera traps, occupying alpine areas of the Alaska Range in interior Alaska, from 2013 to 2014. We tested hypotheses about how habitat use of these species within and between groups varied by spatial and temporal covariates. Furthermore, we modeled two-species occupancy of brown bears (Ursus arctos Linnaeus, 1758) and gray wolves (Canis lupus Linnaeus, 1758) against different potential prey species. Our results suggest that medium-sized and large herbivore use was positively correlated with fine-scale covariates including rock, forb, and graminoid coverage. Large herbivore habitat use was also correlated with abiotic landscape covariates. Detection probabilities of predators and Dall’s sheep (Ovis dalli dalli Nelson, 1884) was improved by camera traps on wildlife trails. Two-species models suggested co-occurrence of habitat use between brown bear – caribou (Rangifer tarandus (Linnaeus, 1758)) and gray wolf – caribou. Results demonstrate the sympatric habitat use by multiple groups of mammals within Alaskan alpine ecosystems and the importance of incorporating multiple groups and spatial scales when making management decisions.

Invisible barriers: anthropogenic impacts on inter- and intra-specific interactions as drivers of landscape-independent fragmentation

Anthropogenically induced fragmentation constitutes a major threat to biodiversity. Presently, conservation research and actions focus predominantly on fragmentation caused directly by physical transformation of the landscape (e.g. deforestation, agriculture, urbanization, roads, etc.). While there is no doubt that landscape features play a key role in fragmenting populations or enhancing connectivity, fragmentation may also come about by processes other than the transformation of the landscape and which may not be readily visible. Such landscape-independent fragmentation (LIF) usually comes about when anthropogenic disturbance alters the inter- and intra-specific interactions among and within species. LIF and its drivers have received little attention in the scientific literature and in the management of wildlife populations. We discuss three major classes of LIF processes and their relevance for the conservation and management of species and habitats: (i) interspecific dispersal dependency, in which populations of species that rely on other species for transport and propagation become fragmented as the transporting species declines; (ii) interspecific avoidance induction, where species are excluded from habitats and corridors owing to interspecific interactions resulting from anthropogenically induced changes in community structure (e.g. exclusions by increased predation pressure); and (iii) intraspecific behavioural divergence, where populations become segregated owing to anthropogenically induced behavioural differentiation among them.

This article is part of the theme issue ‘Linking behaviour to dynamics of populations and communities: application of novel approaches in behavioural ecology to conservation'.

Resource selection by coyotes (Canis latrans) in a longleaf pine (Pinus palustris) ecosystem: effects of anthropogenic fires and landscape features

Prescribed fire is used to restore and maintain fire-dependent forest communities. Because fire affects food and cover resources, fire-mediated resource selection has been documented for many wildlife species. The first step in understanding these interactions is to understand resource selection of the predators in a fire-maintained system. We attached GPS radio collars to 27 coyotes (Canis latrans Say, 1823) and examined resource selection relative to fire-maintained vegetation types, years since fire, anthropogenic features that facilitate prescribed burning, and other landscape features likely to affect coyote resource selection. Coyote home ranges were characterized by more open vegetation types and more recently burned forest (i.e., burned 0–1 year prior) than available on the study area. Within their home ranges, coyotes avoided areas close to densely vegetated drainages and paved roads. Coyote selection of more recently burned forest likely was in response to greater prey density or increased ability to detect prey soon after vegetation cover was reduced by fires; similarly, coyotes likely avoided drainages due to decreased hunting efficiency. Coyote resource selection was linked to prescribed fire, suggesting the interaction between fire and coyotes may influence ecosystem function in fire-dependent forests.

Co-occurrence dynamics of endangered Lower Keys marsh rabbits and free-ranging domestic cats: Prey responses to an exotic predator removal program

The Lower Keys marsh rabbit (Sylvilagus palustris hefneri) is one of many endangered endemic species of the Florida Keys. The main threats are habitat loss and fragmentation from sea-level rise, development, and habitat succession. Exotic predators such as free-ranging domestic cats (Felis catus) pose an additional threat to these endangered small mammals. Management strategies have focused on habitat restoration and exotic predator control. However, the effectiveness of predator removal and the effects of anthropogenic habitat modifications and restoration have not been evaluated. Between 2013 and 2015, we used camera traps to survey marsh rabbits and free-ranging cats at 84 sites in the National Key Deer Refuge, Big Pine Key, Florida, USA. We used dynamic occupancy models to determine factors associated with marsh rabbit occurrence, colonization, extinction, and the co-occurrence of marsh rabbits and cats during a period of predator removal. Rabbit occurrence was positively related to freshwater habitat and patch size, but was negatively related to the number of individual cats detected at each site. Furthermore, marsh rabbit colonization was negatively associated with relative increases in the number of individual cats at each site between survey years. Cat occurrence was negatively associated with increasing distance from human developments. The probability of cat site extinction was positively related to a 2-year trapping effort, indicating that predator removal reduced the cat population. Dynamic co-occurrence models suggested that cats and marsh rabbits co-occur less frequently than expected under random conditions, whereas co-detections were site and survey-specific. Rabbit site extinction and colonization were not strongly conditional on cat presence, but corresponded with a negative association. Our results suggest that while rabbits can colonize and persist at sites where cats occur, it is the number of individual cats at a site that more strongly influences rabbit occupancy and colonization. These findings indicate that continued predator management would likely benefit endangered small mammals as they recolonize restored habitats.

Estimating wildlife activity curves: comparison of methods and sample size

Camera traps and radiotags commonly are used to estimate animal activity curves. However, little empirical evidence has been provided to validate whether they produce similar results. We compared activity curves from two common camera trapping techniques to those from radiotags with four species that varied substantially in size (~1 kg–~50 kg), diet (herbivore, omnivore, carnivore), and mode of activity (diurnal and crepuscular). Also, we sub-sampled photographs of each species with each camera trapping technique to determine the minimum sample size needed to maintain accuracy and precision of estimates. Camera trapping estimated greater activity during feeding times than radiotags in all but the carnivore, likely reflective of the close proximity of foods readily consumed by all species except the carnivore (i.e., corn bait or acorns). However, additional analyses still indicated both camera trapping methods produced relatively high overlap and correlation to radiotags. Regardless of species or camera trapping method, mean overlap increased and overlap error decreased rapidly as sample sizes increased until an asymptote near 100 detections which we therefore recommend as a minimum sample size. Researchers should acknowledge that camera traps and radiotags may estimate the same mode of activity but differ in their estimation of magnitude in activity peaks.

Prey use by dingoes in a contested landscape: Ecosystem service provider or biodiversity threat?

In Australia, dingoes (Canis lupus dingo) have been implicated in the decline and extinction of a number of vertebrate species. The lowland Wet Tropics of Queensland, Australia is a biologically rich area with many species of rainforest-restricted vertebrates that could be threatened by dingoes; however, the ecological impacts of dingoes in this region are poorly understood. We determined the potential threat posed by dingoes to native vertebrates in the lowland Wet Tropics using dingo scat/stomach content and stable isotope analyses of hair from dingoes and potential prey species. Common mammals dominated dingo diets. We found no evidence of predation on threatened taxa or rainforest specialists within our study areas. The most significant prey species were northern brown bandicoots (Isoodon macrourus), canefield rats (Rattus sordidus), and agile wallabies (Macropus agilis). All are common species associated with relatively open grass/woodland habitats. Stable isotope analysis suggested that prey species sourced their nutrients primarily from open habitats and that prey choice, as identified by scat/stomach analysis alone, was a poor indicator of primary foraging habitats. In general, we find that prey use by dingoes in the lowland Wet Tropics does not pose a major threat to native and/or threatened fauna, including rainforest specialists. In fact, our results suggest that dingo predation on "pest" species may represent an important ecological service that outweighs potential biodiversity threats. A more targeted approach to managing wild canids is needed if the ecosystem services they provide in these contested landscapes are to be maintained, while simultaneously avoiding negative conservation or economic impacts.