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1. Living on the edge: spatial response of coyotes ( Canis latrans ) to wolves ( Canis lupus ) in the subarctic

   https://doi.org/10.1139/cjz-2020-0050  

   Klauder, Kaija ; Borg, Bridget L. ; Prugh, Laura R. ( April 2021 , Canadian Journal of Zoology)

   null (Ed.)

   Understanding how mesopredators manage the risks associated with apex predators is key to explaining impacts of apex predators on mesopredator populations and patterns of mesopredator space use. Here we examine the spatial response of coyotes (Canis latrans Say, 1823) to risk posed by wolves (Canis lupus Linnaeus, 1758) using data from sympatric individuals fitted with GPS collars in subarctic Alaska, USA, near the northern range limit for coyotes. We show that coyotes do not universally avoid wolves, but instead demonstrate season-specific responses to both wolf proximity and long-term use of the landscape by wolves. Specifically, coyotes switched from avoiding wolves in summer to preferring areas with wolves in winter, and this selection was consistent across short-term and longer term temporal scales. In the summer, coyotes responded less strongly to risk of wolves when in open areas than when in closed vegetation. We also demonstrate that coyotes maintain extremely large territories averaging 291 km 2 , and experience low annual survival (0.50) with large carnivores being the largest source of mortality. This combination of attraction and avoidance predicated on season and landcover suggests that mesopredators use complex behavioral strategies to mediate the effects of apex predators. 

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2. Coyotes take advantage of ungulate carrion subsidies as wolves recolonize Washington

   https://doi.org/10.1139/cjz-2024-0019  

   Malesis, Anna N ; Windell, Rebecca M ; Vanbianchi, Carmen M ; Prugh, Laura R ( June 2024 , Canadian Journal of Zoology)

   Apex predators exert suppressive effects on mesocarnivores; however, they also provide important carrion subsidies. Optimal foraging theory predicts that individuals respond to resource competition by using high-value resources, while competition theory predicts that individuals respond by partitioning resources. This study investigated how the return of wolves ( Canis lupus Linneas, 1758) to Washington state impacted the diet of a subordinate carnivore—the coyote ( Canis latrans Say, 1823). We collected coyote scats from two areas of northern Washington with differing wolf densities and used traditional analysis of undigested remains to infer diet. We tested for differences in the volumes of prey categories, the proportion of ungulate prey that was scavenged, and diet diversity between seasons, study sites, and inside and outside of wolf pack territories. Coyote scats contained more adult ungulate remains inside of wolf pack territories (27%) compared to outside (14%), while seeds and berries were more commonly consumed outside of wolf pack territories (23%) than inside of wolf pack territories (4%). These findings suggest that coyotes are taking advantage of wolf kills to increase ungulate carrion consumption, as predicted by optimal foraging theory, which may substantially affect plant and wildlife communities as wolves continue to recover and coyote diets shift in response.

    

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3. Can a mesocarnivore fill the functional role of an apex predator?

   https://doi.org/10.1002/ecs2.4383  

   Avrin, Alexandra C. ; Pekins, Charles E. ; Wilmers, Christopher C. ; Sperry, Jinelle H. ; Allen, Maximilian L. ( January 2023 , Ecosphere)

   As keystone species, apex predators play a role in structuring most ecosystems through competition and facilitation, thereby affecting community structure, prey abundance and behavior, vegetation, and abiotic processes. Apex predators are also highly threatened and have been extirpated from much of North America, leading to mesocarnivores, such as coyotes (Canis latrans), becoming de facto apex predators in many ecosystems. However, it is unknown if these mesocarnivores can fill the same functional keystone role as true apex predators. We compared the spatial and temporal habitat use of mesocarnivores in two similar study systems, one with pumas (Puma concolor) and one without, to determine how the role of coyotes in structuring the carnivore community changes in the absence of pumas. We used multispecies occupancy and relative abundance models to examine the spatial avoidance of pumas and coyotes by the smaller mesocarnivores, and temporal overlap and avoidance‐attraction ratios to examine temporal avoidance. We found that coyotes partially fill the functional role of apex predators, but with weaker effects than pumas. Where pumas were absent, site use intensity and relative abundance increased for coyotes (180% and 1250%) and raccoons (Procyon lotor, 308% and 3273%) and decreased for bobcats (Lynx rufus, 36% and 55%), gray foxes (Urocyon cinereoargenteus, 13% and 32%), and striped skunks (Mephitis mephitis, 3% and 12%). Coyotes and raccoons shifted their temporal activity away from pumas, while gray foxes shifted their activity closer to pumas. Detection likelihood decreased for all species after detection of a puma (67%–93%) or coyote (46%–94%) in both sites, but small mesocarnivores avoided pumas more than coyotes in the study area with both. Interactions between carnivores are complex and best understood with multiple measures and in the context of the full community. While coyotes appear to suppress smaller mesocarnivores by some measures (e.g., temporal avoidance), they do not by others (e.g., spatial avoidance) and have overall weaker effects than pumas. Our results suggest that coyotes are not a substitute for apex predators, and conserving true apex predators is likely important for maintaining ecosystem health.

    

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4. Humans drive spatial variation in mortality risk for a threatened wolf population in a Canis hybrid zone

   https://doi.org/10.1111/1365-2664.14589  

   Benson, John F. ; Mahoney, Peter J. ; Wheeldon, Tyler J. ; Thompson, Connor A. ; Ward, Mariah E. ; McLaren, Ashley A. D. ; Desy, Glenn E. ; Fryxell, John M. ; Patterson, Brent R. ( January 2024 , Journal of Applied Ecology)

   Large carnivores often exhibit high survival rates in protected areas, whereas intentional and unintentional human‐caused mortality may be greater in adjacent areas. These patterns can result in source‐sink dynamics and limit population expansion beyond protected areas.

   We used telemetry data from 438 canids in 141 packs collected from 2002 to 2020 to evaluate mortality risk for wolves, coyotes, and admixed canids in a 3‐species hybrid zone in and adjacent to a large protected area in Ontario, Canada. The hybrid zone is occupied by most of the remaining eastern wolves (Canis lycaon), a rare, threatened species that hybridizes with sympatric eastern coyotes (C. latrans) and Great Lakes grey wolves (C. lupus).

   Within Algonquin Provincial Park (APP), annual human‐caused mortality from harvest and vehicles was low (0.06, 95% CI [0.03, 0.08]), whereas annual human‐caused mortality was higher in adjacent areas (0.31, 95% CI [0.25, 0.37]). Smaller protected areas implemented to help protect eastern wolves did not significantly reduce mortality. Eastern wolves survived poorly relative to other canids and dispersing canids survived poorly relative to residents. Mortality risk was greater when canids were closer to roads. Mortality risk was also increased or reduced by the strength of individual‐level selection or avoidance of roads relative to their availability, respectively.

   Our results provide a comprehensive evaluation of factors influencing spatial variation in mortality risk for canids to inform eastern wolf recovery efforts. Additionally, we developed a novel modelling approach for investigating the influence of resource selection on mortality risk, which highlighted that individual‐level responses to risk can strongly influence population‐level mortality patterns.

   Synthesis and applications. Despite being listed as ‘threatened’ under the Ontario Endangered Species Act, eastern wolves are still legally trapped and shot outside protected areas in central Ontario. Eastern wolves and dispersing canids survive poorly outside of APP, primarily from human‐caused mortality. These results, along with the apparent inadequacy of the smaller protected areas, suggest that expanding the threatened eastern wolf population outside APP is unlikely under current management conditions. Protecting eastern wolves from human‐caused mortality is complicated as it would require a harvest ban for all canids, including coyotes.

    

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5. Differential response of three large mammal species to human recreation in the Rocky Mountains of Colorado, USA

   https://doi.org/10.3389/fcosc.2023.1234157  

   Uetrecht, Madison R. ; Bermudez, April ; Novoa, Daniel ; Reithel, Jennifer ; Rodriguez, Vaneza ; Smith, Rosemary ; Sprott, Shannon ; Tingley, Morgan W. ; Blumstein, Daniel T. ( November 2023 , Frontiers in Conservation Science)

   Outdoor recreation benefits local economies, environmental education, and public health and wellbeing, but it can also adversely affect local ecosystems. Human presence in natural areas alters feeding and reproductive behaviors, physiology, and population structure in many wildlife species, often resulting in cascading effects through entire ecological communities. As outdoor recreation gains popularity, existing trails are becoming overcrowded and new trails are being built to accommodate increasing use. Many recreation impact studies have investigated effects of the presence or absence of humans while few have investigated recreation effects on wildlife using a gradient of disturbance intensity. We used camera traps to quantify trail use by humans and mid- to large-sized mammals in an area of intense outdoor recreation–the Upper East River Valley, Colorado, USA. We selected five trails with different types and intensities of human use and deployed six cameras on each trail for five weeks during a COVID-enhanced 2020 summer tourism season. We used occupancy models to estimate detectability and habitat use of the three most common mammal species in the study area and determined which human activities affect the habitat use patterns of each species. Human activities affected each species differently. Mule deer (Odocoileus hemionus) tended to use areas with more vehicles, more predators, and greater distances from the trailhead, and they were more likely to be detected where there were more bikers. Coyotes (Canis latrans) and red foxes (Vulpes vulpes) were most likely to use areas where their prey species occurred, and foxes were more likely to be detected where the vegetation was shorter. Humans and their recreational activities differentially influence different species. More generally, these results reinforce that it is unlikely that a single management policy is suitable for all species and management should thus be tailored for each target species.

    

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