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The recovery of mammalian species in the US Midwest through natural recolonization constitutes a conservation success story, yet management remains challenging due to many unknowns related to population dynamics and numeric trends. Abundance is a critical parameter for management decisions, and estimating the density and abundance of elusive species, such as terrestrial carnivores, remains challenging despite recent technological advances. In this study, we evaluated density and abundance of a recovering carnivore species, the bobcat (Lynx rufus) in two areas of Ohio using non‐invasive DNA from scat. The target areas in eastern and southern Ohio have been shown to have uneven dynamics and recolonization success and we expected that this would be reflected in differences in density and abundance. We collected 298 bobcat scats between July 2018 and April 2019 on 150 km of repeated transects. Of these, 102 scats were successfully genotyped, and 55 individuals were identified (33 in eastern Ohio and 22 in southern Ohio). Using Spatially Explicit Capture–Recapture models, we estimated 18.9 ± 4.1 and 10.9 ± 2.7 bobcats/100 km2 in eastern and southern Ohio study areas, respectively. Our results support prior telemetry data which indicated that bobcats in eastern Ohio had smaller home‐ranges than bobcats in southern Ohio, and thus could support a higher density of individuals. The higher densities were similar to other eastern US populations and are much higher than other Midwestern recovering populations. Our results provide a snapshot of the population status and can be used to determine sustainable management strategies for Ohio's bobcat population. [ABSTRACT FROM AUTHOR]

We conducted surveillance of mammals to investigate their associations with argasid ticks and tick-borne pathogens. During 2021, a total of 20 wild carnivores and 57 lagomorphs were sampled, and 39 argasid ticks belonging to two species were collected. All mammals and ticks were tested by molecular assays to detect Borrelia and Rickettsia infections. Nine ticks identified as Otobius megnini were collected from two coyotes (Canis latrans) and 30 Alveonasus cooleyi (McIvor 1941) were collected from six bobcats (Lynx rufus) and one rabbit (Sylvilagus auduboni). We detected Rickettsia spp. DNA in 21 of the 27 (77.8%) tested Av. cooleyi and none of the O. megnini. No ticks were PCR-positive for borreliae and all mammals were PCR-negative for both pathogen genera. Phylogenetic analysis based on gltA, htrA, and 16 S rRNA targets revealed that all rickettsiae from Av. cooleyi clustered with ancestral group rickettsiae, likely representing a novel species of possibly endosymbiotic Rickettsia. The significance of Av. cooleyi and the newly identified Rickettsia sp. to the health of wildlife is unknown, and further work is indicated to determine whether they may be relevant to public health or carnivore conservation. [ABSTRACT FROM AUTHOR]

Delineating wildlife population boundaries is important for effective population monitoring and management. The bobcat (Lynx rufus) is a highly mobile generalist carnivore that is ecologically and economically important. We sampled 1225 bobcats harvested in South Dakota, USA (2014–2019), of which 878 were retained to assess genetic diversity and infer population genetic structure using 17 microsatellite loci. We assigned individuals to genetic clusters (K) using spatial and nonspatial Bayesian clustering algorithms and quantified differentiation (FST and GST″$$ {G}_{\mathrm{ST}}^{{\prime\prime} } $$) among clusters. We found support for population genetic structure at K = 2 and K = 4, with pairwise FST and GST″$$ {G}_{\mathrm{ST}}^{{\prime\prime} } $$ values indicating weak to moderate differentiation, respectively, among clusters. For K = 2, eastern and western clusters aligned closely with historical bobcat management units and were consistent with a longitudinal suture zone for bobcats previously identified in the Great Plains. We did not observe patterns of population genetic structure aligning with major rivers or highways. Genetic divergence observed at K = 4 aligned roughly with ecoregion breaks and may be associated with environmental gradients, but additional sampling with more precise locational data may be necessary to validate these patterns. Our findings reveal that cryptic population structure may occur in highly mobile and broadly distributed generalist carnivores, highlighting the importance of considering population structure when establishing population monitoring programs or harvest regulations. Our study further demonstrates that for elusive furbearers, harvest can provide an efficient, broad‐scale sampling approach for genetic population assessments. [ABSTRACT FROM AUTHOR]

Bobcats (Lynx rufus) are the most broadly distributed native felid in North America and have substantial ecological and economic importance. Despite this importance, little is known about factors influencing population dynamics of this cryptic carnivore. Given recent apparent declines in abundance, we investigated population growth rate (λ) for a bobcat population in the Black Hills, South Dakota, USA, 2016–2022. We constructed and evaluated a females‐only matrix population model. Our estimate of asymptotic λ, derived from estimates of vital rates obtained over 6 years, was 0.85 (95% CI = 0.72, 1.02), which indicates that the vital rates in 2016–2022 were inadequate to sustain the population. Elasticity and sensitivity values were highest for changes in adult survival probability followed by, in order, changes in kitten and juvenile survival and adult reproductive contribution. Life‐stage simulation analysis also supported that adult survival was most important; however, the juvenile survival (91 day–1 year) component of a bobcat's first year of life was also important and a stronger influence on population growth than the kitten survival (first 90 days) component. For the combination of survival and reproductive rates we estimated positive population growth required either annual adult survival >0.85 or 275‐day juvenile survival >0.35, regardless of other vital rates. When assuming a baseline harvest rate of 23.5%, reducing the harvest rate to 9% led to a positive mean growth rate and a >0.50 probability of a growing population. Monitoring juvenile‐to‐adult harvest ratios can provide an indicator of age structure in the population, and we recommend restricting harvest when that ratio falls below 10%, particularly when managers lack research information on population growth. [ABSTRACT FROM AUTHOR]

Severe musculoskeletal diseases, such as those associated with congenital or traumatic events, that result in missing limbs may compromise the fitness and survival of free‐living felids. Here we report the space use of four amputee individuals from three felid species captured from 2017 to 2022 in Missouri (USA), Toledo and Badajoz (Spain), and Suitai Khairkhan Mountain (Mongolia). We describe home ranges and daily travel distances post‐release of free‐living felids that had either suffered a traumatic amputation or following a surgical amputation. We compared these data with those reported in the literature for felids without amputations. Forelimb or hindlimb amputation did not affect the hunting, mating, or territory patrolling behavior of any of the individuals. However, we recorded significant differences in the daily movement before and after the traumatic event of the Iberian lynx forelimb amputee. We attribute this difference to the physical impairment, although we consider other variables that may have played a role. Nevertheless, all animals appeared to cope well with their limb loss, showing home ranges and daily distances within those recorded for their sex and species. Unless amputee felids represent a threat to domestic livestock or humans, our data suggest these individuals may remain free‐living as they contribute to local population persistence and appear to maintain good general health and welfare. [ABSTRACT FROM AUTHOR]

Bobcats (Lynx rufus) are terrestrial mammals that also inhabit tree islands (i.e., topographically elevated patches of forested land) embedded in the subtropical Everglades wetlands, which serve as a dry refuge habitat during the wet season in this region of Florida, USA. The Comprehensive Everglades Restoration Plan seeks to restore Everglades water flow to pre‐drainage conditions, but little is known about how water levels or other landscape‐level factors may influence mammalian occurrence, such as bobcats, on the tree islands in this ecosystem. We used game camera records and occupancy modeling to test for effects of static habitat variables and dynamic hydrologic variables. We hypothesized that deep water levels would limit the accessibility of tree islands to bobcats; therefore, we predicted that bobcat occupancy would decline with higher water levels. We also tested for the effect of an expanding invasive snake (i.e., Burmese python [Python molarus bivittatus]) using output from a model constructed to predict density and spread of Burmese pythons across southern Florida. We hypothesized that increases in Burmese pythons on the landscape would influence the food resources of bobcats, resulting in reduced bobcat occupancy at higher predicted densities of pythons. We built detection histories using 1,855 bobcat images from game cameras set on 87 tree islands in an Everglades conservation area from 2005–2019. Bobcat occupancy was significantly diminished when predicted Burmese python densities exceeded approximately 3 Burmese pythons/km2. Bobcat occupancy probability also increased with tree‐island density around the focal tree island. Although water depth and hydroperiod surrounding tree islands appeared in our top 3 candidate models, the hydrologic variables had weak effects on bobcat occupancy. Our results suggest that while hydrologic dynamics may play a role, the invasive Burmese python has stronger influences on bobcat occupancy of tree islands in this Everglades conservation area. [ABSTRACT FROM AUTHOR]

Chemical immobilization agents that provide rapid induction time, short duration of action, wide margin of safety, and postreversal recovery are important attributes to the handling process of immobilized animals. We evaluated differences in induction, recovery, and physiologic parameters in 23 (13 female, nine adults and four yearlings; 10 male, nine adults and one yearling) free-ranging bobcats (Lynx rufus) chemically immobilized with an intramuscular combination of ketamine (10 mg/kg) and xylazine (KX; 1.5 mg/kg; n=11) or a combination of butorphanol (0.8 mg/ kg), azaperone (0.27 mg/kg), and medetomidine (BAM; 0.32 mg/kg; n=12). Induction parameters, time to first effect, hemoglobin oxygen saturation, and anesthesia between bobcats administered KX and BAM were similar. Pulse rate was significantly higher for KX than for BAM. Time to standing and full recovery after reversal were faster for bobcats administered BAM than KX. Six of 11 (55%) bobcats given KX were effectively immobilized with a single injection, and five required additional drugs to allow adequate time for processing. Of 12 bobcats given BAM, six (50%) were effectively immobilized with a single injection, three (25%) individuals were not completely immobilized and required additional doses to allow adequate time for processing, and three (25%) required additional doses after complete arousal during processing. We found that BAM provided reduced sedation and processing times (<30 min), whereas KX provided extended sedation and processing times beyond 30 min. We suggest that researchers increase initial BAM drug volumes for yearling and adult bobcats at time of processing and consider taking appropriate safety precautions when handling free-ranging bobcats. [ABSTRACT FROM AUTHOR]

Context. Adding an attractant to remote camera traps has become a popular method to increase detections of cryptic carnivores. However, there is ongoing debate about whether this practice can biasthe behaviour and activity patterns of these species. Aims. Our aim wasto determine how using a popular attractant at camera traps could affect carnivore detection probabilities and temporal activity. Methods. We used an experimental design in which we randomly set half of our camera traps on arrays at two sites in western North Carolina with an attractant: canned sardines in oil. Halfway through the survey season, we switched which camera traps had sardines and which did not. We estimated detection probability for each carnivore species observed using occupancy models, and we used kernel density estimations to evaluate changes in diel activity patterns between camera traps with and without an attractant. Key results. We found that when sardines were used at camera traps, detectability of bobcats (Lynx rufus), coyotes (Canis latrans), northern raccoons (Procyon lotor), Virginia opossums(Didelphisvirginiana), and eastern spotted skunks(Spilogale putorius) more than doubled, but there waslittle or no effect on striped skunk (Mephitis mephitis) detectability. Of the species we most frequently detected (coyotes, raccoons, and opossums), activity patterns between camera traps with and without a sardine attractant overlapped moderately to highly, and a significant effect on diel activity patterns was observed only for raccoons. Conclusions. Use of attractants can greatly increase the probability of detecting nearly all carnivores at camera traps. The effects of attractants on diel activity patterns are species-specific, with two of our three most-detected species unaffected by their use, suggesting that attractants can be used to effectively study these behaviours in some carnivore species. Implications. A sardine attractant can increase the detection of many carnivore species, using camera traps, without causing a significant deviation of diel activity patterns, thus allowing for unbiased investigations into most species’ spatio–temporal behaviour in the Appalachian Mountains – and likely other systems. [ABSTRACT FROM AUTHOR]

Abstract Delineating wildlife population boundaries is important for effective population monitoring and management. The bobcat (Lynx rufus) is a highly mobile generalist carnivore that is ecologically and economically important. We sampled 1225 bobcats harvested in South Dakota, USA (2014–2019), of which 878 were retained to assess genetic diversity and infer population genetic structure using 17 microsatellite loci. We assigned individuals to genetic clusters (K) using spatial and nonspatial Bayesian clustering algorithms and quantified differentiation (FST and GST″) among clusters. We found support for population genetic structure at K = 2 and K = 4, with pairwise FST and GST″ values indicating weak to moderate differentiation, respectively, among clusters. For K = 2, eastern and western clusters aligned closely with historical bobcat management units and were consistent with a longitudinal suture zone for bobcats previously identified in the Great Plains. We did not observe patterns of population genetic structure aligning with major rivers or highways. Genetic divergence observed at K = 4 aligned roughly with ecoregion breaks and may be associated with environmental gradients, but additional sampling with more precise locational data may be necessary to validate these patterns. Our findings reveal that cryptic population structure may occur in highly mobile and broadly distributed generalist carnivores, highlighting the importance of considering population structure when establishing population monitoring programs or harvest regulations. Our study further demonstrates that for elusive furbearers, harvest can provide an efficient, broad‐scale sampling approach for genetic population assessments.

Abstract Severe musculoskeletal diseases, such as those associated with congenital or traumatic events, that result in missing limbs may compromise the fitness and survival of free‐living felids. Here we report the space use of four amputee individuals from three felid species captured from 2017 to 2022 in Missouri (USA), Toledo and Badajoz (Spain), and Suitai Khairkhan Mountain (Mongolia). We describe home ranges and daily travel distances post‐release of free‐living felids that had either suffered a traumatic amputation or following a surgical amputation. We compared these data with those reported in the literature for felids without amputations. Forelimb or hindlimb amputation did not affect the hunting, mating, or territory patrolling behavior of any of the individuals. However, we recorded significant differences in the daily movement before and after the traumatic event of the Iberian lynx forelimb amputee. We attribute this difference to the physical impairment, although we consider other variables that may have played a role. Nevertheless, all animals appeared to cope well with their limb loss, showing home ranges and daily distances within those recorded for their sex and species. Unless amputee felids represent a threat to domestic livestock or humans, our data suggest these individuals may remain free‐living as they contribute to local population persistence and appear to maintain good general health and welfare.

Bobcats (Lynx rufus) were extirpated from many midwestern states in the mid‐1800s owing to habitat loss and overharvesting. Recently, bobcats have recolonized Ohio, USA, and neighboring states and given their furbearer status elsewhere, there is interest in opening a harvest season; however, demographic factors and viability of this population are currently unknown. We developed a spatial population simulation model to assess the long‐term viability of the bobcat population in Ohio in the face of 2 human‐induced factors limiting population growth: potential harvest and road mortality. We combined habitat suitability and road mortality risk data with vital rates for bobcats from Ohio and other populations to simulate possible scenarios for Ohio's population. Our baseline scenario simulations showed no risk of extinction for Ohio's bobcat population in the next 40 years, but population trajectories were lower and exhibited greater uncertainty when we modeled the population with a lower maximum density of animals per cell. At low harvest intensity (αh = 0.05), the bobcat population also exhibits low risk of extinction. When harvest intensity increases (αh = 0.1, 0.15) or when adults (≥2 yr) are targeted by harvest, simulations show declining populations, greater uncertainty in projections, and possible risk of extirpation. Our models indicated that if harvest and road mortality are additive, then the bobcat population could withstand marginal increases in road mortality (αr = 0.1) at low harvest intensity (αh = 0.05). Future increases in road mortality with higher harvest intensity (αh = 0.1, 0.15) were unsustainable. Our results can be used by wildlife managers to assist with decisions on population‐level management. This simulation model can easily be adapted for other large mammals and can be modified to assess a variety of ecological and anthropogenic influences to wildlife populations. [ABSTRACT FROM AUTHOR]

Cytauxzoonosis is a fatal tick-borne disease in domestic cats caused by infection with the apicomplexan Cytauxzoon felis. Bobcats are the natural wild-vertebrate reservoirs for C. felis, and infections are typically subclinical and chronic in this species. The present study was done to determine the prevalence and geographic distribution of C. felis infection in wild bobcats from Oklahoma and the occurrence in northwestern Texas. Tongue samples from 360 bobcats were collected from 53 counties in Oklahoma and 13 samples from three counties in Texas. For DNA extracted from each tongue sample, a probe-based droplet digital PCR assay was performed targeting the C. felis mitochondrial gene cytochrome c oxidase subunit III (cox3). Prevalence of C. felis infection was calculated for each county sampled, and data from individual counties were combined according to geographic regions and compared using chi-square tests. Overall prevalence of C. felis in bobcats from Oklahoma was 80.0% (95% confidence interval [CI], 75.6–83.8). The prevalence of infection was >90% for bobcats from central, northeastern, south-central, and southeastern regions of Oklahoma, but <68% for bobcats from northwestern and southwestern regions. Bobcats from central counties in Oklahoma were 25.693 times more likely to be infected with C. felis compared to all other bobcats sampled from the state. Higher prevalence estimates of C. felis in bobcats appeared to be in counties where known tick vectors are most common. Occurrence of C. felis in bobcats from northwestern Texas was 30.8% (95% CI, 12.4%–58.0%) based on 13 samples. Results of this study support the utilization of bobcats as sentinel animals to identify geographic areas with risk of C. felis infection to domestic cats. [ABSTRACT FROM AUTHOR]

Since 2000, the Alameda County Vector Control Services District has received only 10 requests for service regarding bobcats. Seven of those cases have occurred in the past three years. Of those, only one case has involved the bobcats creating a den on a residential property. This is the case study of a mother bobcat and four kittens denning in the backyard of a suburban home in Fremont, California. The eviction of the bobcats from the deck of the vacant home was completed in May and June of 2019. During a four-week period, a wide range of eviction techniques were used, including noise, light, and water harassment, along with eviction fluid and human presence. This experience gave us the opportunity to observe and record the behaviors of bobcats living in a suburban environment and to test various eviction methods that had previously been untested in Alameda County. After four weeks of continuous humane harassment, the eviction was successful.

The Cheadle Center at UCSB manages the North Campus Open Space (NCOS), which is a project that has restored 136 acres of upland and wetland habitats that existed before the area was converted into the Ocean Meadows Golf Course in the 1960s. The NCOS restoration project began in 2017 with a fine-scale grading of the site in order to recreate the salt marsh and use the excavated soil to rebuild the upland habitats to the southwest, which are now called the NCOS Mesa. In addition to re-establishing native biodiversity, a key goal of the restoration is to utilize the site as an educational, scientific, and recreational resource. This archived version of the December 2019 newsletter includes updates on public events and a recent tracking workshop that revealed activity of burrowing owl (Athene cunicularia), barn owl (Tyto alba), red fox (Vulpes vulpes), bobcat (Lynx rufus), striped skunk (Mephitis mephitis), and many other animals. The feature story focuses on predator-prey interactions and how neighbors can help support natural predators and avoid introducing unnatural ones such as cats. Community photos include Cooper’s Hawk (Accipiter cooperii), Marsh Wren (Cistothorus palustris), and Pied-billed Grebe (Podilymbus podiceps).

The Cheadle Center at UCSB manages the North Campus Open Space (NCOS), which is a project that has restored 136 acres of upland and wetland habitats that existed before the area was converted into the Ocean Meadows Golf Course in the 1960s. The NCOS restoration project began in 2017 with a fine-scale grading of the site in order to recreate the salt marsh and use the excavated soil to rebuild the upland habitats to the southwest, which are now called the NCOS Mesa. In addition to re-establishing native biodiversity, a key goal of the restoration is to utilize the site as an educational, scientific, and recreational resource. This archived version of the November 2019 newsletter includes updates on tidewater goby (Eucyclogobius newberryi) and other fish being found in the slough, Ventura Marsh Milk-Vetch (Astragalus pycnostachyus var. lanosissimus) reintroduction, and visitor plaza construction. The feature story focuses on vegetation monitoring and planting. Community photos include Burrowing Owl (Athene cunicularia), Bobcat (Lynx rufus), and Red-necked Phalarope (Phalaropus lobatus).

The Cheadle Center at UCSB manages the North Campus Open Space (NCOS), which is a project that has restored 136 acres of upland and wetland habitats that existed before the area was converted into the Ocean Meadows Golf Course in the 1960s. The NCOS restoration project began in 2017 with a fine-scale grading of the site in order to recreate the salt marsh and use the excavated soil to rebuild the upland habitats to the southwest, which are now called the NCOS Mesa. In addition to re-establishing native biodiversity, a key goal of the restoration is to utilize the site as an educational, scientific, and recreational resource. This archived version of the September 2019 newsletter includes updates on weedwhacking to promote plant diversity and new mesa slope plantings. The feature story focuses on water quality monitoring results. Community photos include Red-Tailed Hawk (Buteo jamaicensis) and egrets.

Densidad demográfica y patrones de actividad diaria del gato montés en su área de distribución más meridional del continente. La estimación de la densidad demográfica y de los patrones de actividad diaria es útil para el manejo y la conservación de las especies. Los datos disponibles en relación con las poblaciones mexicanas de gato montés (Lynx rufus) son escasos. Los objetivos de este trabajo fueron estimar la densidad de una población de gato montés y evaluar sus patrones de actividad diaria en Oaxaca, al sur de México. Asimismo, evaluamos patrones macroecológicos de la densidad del gato montés a lo largo de su área de distribución para comprobar si existe algún efecto geográfico (latitud, longitud, elevación y centroide de su área de distribución) o climático en la densidad de la población. Los datos recabados mediante fototrampeo se agruparon en cuatro períodos de 60 días (dos en la estación seca y dos en la estación lluviosa). La densidad se calculó mediante un modelo de encuentros aleatorios y los patrones de actividad diaria se analizaron mediante ajustes de modelos Kernel. La densidad media estimada de los cuatro períodos fue de 17,3 gatos montés/100 km2, con las densidades más altas en las estaciones secas. El patrón de actividad diaria presentó dos picos: uno después de la medianoche y otro después del amanecer, con ligeros cambios entre temporadas. En la zona del estudio, la densidad y los patrones de actividad podrían estar relacionados con la perturbación antropogénica y la disponibilidad de presas. En la estación seca, la población aumentó y los gatos montés prefirieron estar activos durante la noche y la madrugada, cuando la temperatura es más fresca y tienen menos competidores y más presas. En su área de distribución, la densidad del gato montés está ligada principalmente a la precipitación anual y a la temperatura media del cuarto trimestre más seco en un radio de 100 km, y entre la precipitación anual y la longitud a una escala menor (radio de 50 km), lo que respalda el hecho de que el gato montés prefiere ambientes áridos o mésicos, que le permitan llegar a las zonas más meridionales de la región neártica.

Context: Many terrestrial mammals have undergone substantial distribution changes in recent decades; yet collecting broad-scale occurrence data for carnivores is difficult due to their low densities and cryptic behaviors. Carnivore observations from community (i.e., citizen) science programs can be a potentially valuable approach for understanding changes in carnivore distributions over long time periods. Objectives: We used 18 years of bobcat (Lynx rufus) observations collected by archery deer hunters (i.e., participants) across Illinois, USA, to estimate spatiotemporal patterns in occurrence and determine how landscape features influenced patterns of recolonization. Methods: We developed Bayesian spatial and non-spatial multi-scale dynamic occupancy models to estimate county-level occupancy, persistence, and colonization and participant-level occupancy. We modeled county-level parameters as a function of multiple a priori landscape covariates and compared model predictive performance using cross-validation. Results: Our non-spatial occupancy model had greater predictive support than our spatial occupancy model. Mean annual statewide county-level occupancy increased from approximately 0.43–0.83 while mean annual participant-level occupancy increased from approximately 0.07–0.28. Bobcats were primarily restricted to southern Illinois during the early 2000s but by 2018 occurred throughout western and southern Illinois. Landscape covariates had relatively weak effects on model parameters. Conclusions: Our study illustrates how community science observations analyzed with hierarchical occupancy models can be used to model spatiotemporal changes in species distributions. Bobcats have recolonized much of Illinois, but this colonization was not strongly mediated by county-level landscape features at the scales we measured. [ABSTRACT FROM AUTHOR]

The proportion and diversity of prey species consumed by bobcats Lynx rufus are often correlated with prey abundances, individual skill level, environmental conditions, and habitat quality. Bobcats generally consume prey species that rely on mast—the fruits of trees—for basic life-history requirements. In West Virginia forests, many mast-producing tree species have declined over the past 40 y, yet the last known study on bobcat diet in the state was in 1977. Thus, we need current data to understand the effects of forest compositional changes on bobcat dietary patterns. We evaluated stomach contents of 300 bobcats collected over the 2014–2015 (n = 150) and 2015–2016 (n = 150) hunting and trapping seasons in West Virginia. Simpson's index of diversity indicated an 87% probability that two randomly selected prey items belong to different species, supporting the idea of bobcats as generalist carnivores. White-tailed deer (hereafter deer) Odocoileus virginianus (32%), mice and rats (families Cricetidae, Dipodidae, and Muridae; 30.7%), rabbits (family Leporidae; 21.3%), Virginia opossum Didelphis virginiana (18.7%), and squirrels (family Sciuridae; 17.3%) occurred most frequently. We found 92% dietary overlap between sexes and 35% between stage classes. Deer, opossum, and raccoon Procyon lotor occurred more frequently in males, whereas rabbits occurred more frequently in females. Deer occurred more frequently in adults; raccoons in yearlings; and mice and rats in juveniles. Overall occurrence of deer (−17.1%), rodents (order Rodentia; −9.5%), opossum (+13.5%), and raccoon (+5.1%) differed significantly between the 1977 study and this study, which may allude to changes in the abundance of mast-dependent prey species over time. Similarly, hard mast (i.e., nuts) production had a significant interaction effect with study season on the overall occurrence of squirrels in bobcat diets. By improving our understanding of bobcat trophic interactions, we can better manage their populations and ecological communities by managing for the dietary requirements of their common prey species. [ABSTRACT FROM AUTHOR]

Abstract Background Relative to temperate regions, little is known about bobcats (Lynx rufus) in the Sonoran Desert portion of their range, in part due to the difficulty of sampling an elusive carnivore in harsh desert environments. Here, we quantify habitat selection and evaluate diet of bobcats at Kofa National Wildlife Refuge, Arizona, USA, using multiple sampling techniques including GPS telemetry, camera traps, and DNA metabarcoding. Results Home ranges during the hot season were smaller than during the cool season. Camera trapping failed to yield a high enough detection rate to identify habitat occupancy trends but third-order resource selection from GPS-collar data showed a preference for higher elevations and rugged terrain at lower elevations. Diet composition consisted of a diverse range of available small prey items, including a higher frequency of avian prey than previously observed in bobcats. Conclusions Desert bobcats in our study maintained smaller home ranges and primarily consumed smaller prey than their more northern relatives. This study illustrates the benefit of employing multiple, complementary sampling methods to understand the ecology of elusive species.

Understanding how human activities influence immune response to environmental stressors can support biodiversity conservation across increasingly urbanizing landscapes. We studied a bobcat (Lynx rufus) population in urban southern California that experienced a rapid population decline from 2002-2005 due to notoedric mange. Because anticoagulant rodenticide (AR) exposure was an underlying complication in mange deaths, we aimed to understand sublethal contributions of urbanization and ARs on 65 biochemical markers of immune and organ function. Variance in immunological variables was primarily associated with AR exposure and secondarily with urbanization. Use of urban habitat and AR exposure has pervasive, complex and predictable effects on biochemical markers of immune and organ function in free-ranging bobcats that include impacts on neutrophil, lymphocyte and cytokine populations, total bilirubin and phosphorus. We find evidence of both inflammatory response and immune suppression associated with urban land use and rat poison exposure that could influence susceptibility to opportunistic infections. Consequently, AR exposure may influence mortality and has population-level effects, as previous work in the focal population has revealed substantial mortality caused by mange infection. The secondary effects of anticoagulant exposure may be a worldwide, largely unrecognized problem affecting a variety of vertebrate species in human-dominated environments.

Ecological studies investigating niche breadth and overlap often have limited spatial and temporal scale, preventing generalizations across varying environments and communities. For example, it is not clear whether species having restricted diets maintain such patterns relative to closely related species and across their geographic range of co-occurrence. We used stable isotope analysis of hair and fur samples collected from four regions of sympatry for Canada lynx (Lynx canadensis) and bobcat (Lynx rufus) spanning southern Canada and the northern United States, to test the prediction that the more generalist species (bobcat) exhibits a wider dietary niche than the more specialist species (Canada lynx) and that this pattern is consistent across different regions. We further predicted that Canada lynx diet would consistently exhibit greater overlap with that of bobcat compared to overlap of bobcat diet with Canada lynx. We found that Canada lynx had a narrower dietary niche than bobcat, with a high probability of overlap (85–95%) with bobcat, whereas the bobcat dietary niche had up to a 50% probability of overlap with Canada lynx. These patterns of dietary niche breadth and overlap were consistent across geographic regions despite some regional variation in diet breadth and position, for both species. Such consistent patterns could reflect a lack of plasticity in species dietary niches. Given the increasingly recognized importance of understanding dietary niche breadth and overlap across large spatial scales, further research is needed to investigate the mechanisms by which broad-scale patterns are maintained across species and systems.

Human developments have detrimental effects on wildlife populations globally with carnivores being particularly sensitive. The bobcat (Lynx rufus) is often considered an adaptable mesocarnivore that occurs throughout varied landcover types within its wide distribution and may be less susceptible to the negative effects of development. Our objectives were to investigate the landscape occupancy dynamics of bobcats in a highly developed and densely populated region of the northeastern United States to evaluate the sensitivity of bobcat occurrence to natural and anthropogenic landscape features. We established a large‐scale camera trapping survey throughout Rhode Island, USA, sampling from 2018 to 2020. Using dynamic occupancy models, we found initial site occupancy was positively influenced by the amount of forested wetland habitat, while increasing road density and shrub cover negatively influenced the probability of site colonization. Surprisingly, we found no hypothesized variables to influence site‐level extirpation probability, or any seasonal effects on dynamic parameters. Lastly, we found that forest cover and road density negatively influenced the probability of detection. The probability of occupancy was high, >0.8, throughout much of the study area (49%), but we also found relatively high site transients, with the probability a site would change occurrence status from season to season at ≈0.27 in the majority of the study area (70%). Our results show that although bobcats can persist in human‐dominated landscapes, they require contiguous natural areas to do so. Future expansion of road infrastructure may reduce habitat connectivity and increase road mortalities, thus jeopardizing the population. [ABSTRACT FROM AUTHOR]

Spatial biases commonly occur in biodiversity conservation efforts, and bobcats in Mexico exemplify this issue. Bobcats are one of the most well-studied felids worldwide. However, in Mexico bobcat studies are limited despite a wide distributional range. The objective of our study was to review the scientific literature published on bobcats in Mexico from 1988 to 2019 and to identify potential sampling biases. For each study, we identified the year, location, taxonomic focus, topic studied, and georeferenced each research location that included data collection in Mexico. We compared the spatial distribution of bobcat studies to random locations with a generalized linear model with binomial error structure using three variables and their interactions (degree of biome transformation, distance to protected lands, and distance to capital cities). We reviewed 210 publications (including research articles and undergraduate and postgraduate theses). Only in 37 publications were bobcats the single species studied. Bobcat studies have increased in Mexico since 2004 with most (78.57%) published within the 2004–2019 period. The main topic studied was diet, followed by species interactions. All but three states within the bobcat distribution in Mexico have at least one research study. We found that study locations are biased towards the less transformed biomes and protected lands. Bobcats can persist in urbanized landscapes although a threshold of disturbance for the species in Mexico remains unknown. Thus, we suggest bobcat research efforts to be strategically directed to fill knowledge gaps and with greater emphasis on highly transformed landscapes where the species may be at risk. [ABSTRACT FROM AUTHOR]

Although most prey have multiple predator species, few studies have quantified how prey respond to the temporal niches of multiple predators which pose different levels of danger. For example, intraspecific variation in diel activity allows white‐tailed deer (Odocoileus virginianus) to reduce fawn activity overlap with coyotes (Canis latrans) but finding safe times of day may be more difficult for fawns in a multi‐predator context. We hypothesized that within a multi‐predator system, deer would allocate antipredation behavior optimally based on combined mortality risk from multiple sources, which would vary depending on fawn presence. We measured cause‐specific mortality of 777 adult (>1‐year‐old) and juvenile (1–4‐month‐old) deer and used 300 remote cameras to estimate the activity of deer, humans, and predators including American black bears (Ursus americanus), bobcats (Lynx rufus), coyotes, and wolves (Canis lupus). Predation and vehicle collisions accounted for 5.3 times greater mortality in juveniles (16% mortality from bears, coyotes, bobcats, wolves, and vehicles) compared with adults (3% mortality from coyotes, wolves, and vehicles). Deer nursery groups (i.e., ≥1 fawn present) were more diurnal than adult deer without fawns, causing fawns to have 24–38% less overlap with carnivores and 39% greater overlap with humans. Supporting our hypothesis, deer nursery groups appeared to optimize diel activity to minimize combined mortality risk. Temporal refuge for fawns was likely the result of carnivores avoiding humans, simplifying diel risk of five species into a trade‐off between diurnal humans and nocturnal carnivores. Functional redundancy among multiple predators with shared behaviors may partially explain why white‐tailed deer fawn predation rates are often similar among single‐ and multi‐predator systems. [ABSTRACT FROM AUTHOR]

Neonatal mortality is a primary determinant of ungulate population dynamics and occurs from multiple proximal causes, but few studies have compared relationships between risk factors and cause-specific mortality. We evaluated how landscape and physiological characteristics influenced white-tailed deer (Odocoileus virginianus) fawn risk from predators (American black bears [Ursus americanus], bobcats [Lynx rufus], coyotes [Canis latrans], and wolves [Canis lupus]), anthropogenic causes, and non-predation natural causes (i.e., disease, injury, or starvation). We monitored 363 fawns and identified 166 mortalities in the Upper Peninsula of Michigan, USA during 2009–2019. Human development reduced fawn predation, particularly from coyotes, but predation was compensated by vehicle collisions. Coyote predation also was reduced in more forested areas, which was offset by increased predation from black bears, bobcats, and wolves. Smaller birth mass increased risk of non-predation natural mortality but did not influence predation or anthropogenic mortality. Our results suggest that for prey living alongside human development, the survival advantage of a “human shield” from predation can be offset by anthropogenic mortality. Birth mass relationships with mortality contradicted the hypothesis that predators select weaker individuals. We conclude that landscape attributes and fawn characteristics may interact with top-down, bottom-up, and anthropogenic processes to shape neonatal white-tailed deer mortality. Because some causes of mortality have opposing relationships with risk factors, combined mortality risk assessment may mask the processes driving specific mortality causes.

Abstract Although most prey have multiple predator species, few studies have quantified how prey respond to the temporal niches of multiple predators which pose different levels of danger. For example, intraspecific variation in diel activity allows white‐tailed deer (Odocoileus virginianus) to reduce fawn activity overlap with coyotes (Canis latrans) but finding safe times of day may be more difficult for fawns in a multi‐predator context. We hypothesized that within a multi‐predator system, deer would allocate antipredation behavior optimally based on combined mortality risk from multiple sources, which would vary depending on fawn presence. We measured cause‐specific mortality of 777 adult (>1‐year‐old) and juvenile (1–4‐month‐old) deer and used 300 remote cameras to estimate the activity of deer, humans, and predators including American black bears (Ursus americanus), bobcats (Lynx rufus), coyotes, and wolves (Canis lupus). Predation and vehicle collisions accounted for 5.3 times greater mortality in juveniles (16% mortality from bears, coyotes, bobcats, wolves, and vehicles) compared with adults (3% mortality from coyotes, wolves, and vehicles). Deer nursery groups (i.e., ≥1 fawn present) were more diurnal than adult deer without fawns, causing fawns to have 24–38% less overlap with carnivores and 39% greater overlap with humans. Supporting our hypothesis, deer nursery groups appeared to optimize diel activity to minimize combined mortality risk. Temporal refuge for fawns was likely the result of carnivores avoiding humans, simplifying diel risk of five species into a trade‐off between diurnal humans and nocturnal carnivores. Functional redundancy among multiple predators with shared behaviors may partially explain why white‐tailed deer fawn predation rates are often similar among single‐ and multi‐predator systems.

Over the past 20 years, the use of non‐invasive hair snare surveys in wildlife research and management has become more prevalent. While these tools have been used to answer important research questions, these techniques often fail to gather information on elusive carnivores, such as bobcats (Lynx rufus). Due to the limited success of previous bobcat studies using hair snares which required active rubbing, this technique has largely fallen out of use, in favor of camera trapping. The goal of our study was to construct a novel, passive bobcat hair snare that could be deployed regardless of terrain or vegetation features, which would be effective for use in capture–recapture population estimation at a large spatial scale. This new hair snare was deployed in 1500 10‐km2 cells across West Virginia (USA) between two sampling seasons (2015–2016). Collected hair samples were analyzed with newly developed mitochondrial DNA primers specifically for felids and qPCR to determine species of origin, with enough sensitivity to identify samples as small as two bobcat hairs. Over the two years of the study, a total of 378 bobcat detections were recorded from 42,000 trap nights of sampling, for an overall rate of 0.9 detections/100 trap nights—nearly 2–6 times greater than any previous bobcat hair snare study. While the overall number of recaptured animals was low (n = 9), continued development of this platform should increase its usefulness in capture–recapture studies. [ABSTRACT FROM AUTHOR]

Summary: We report on what appear to be increasing predation events on nesting Thick-billed Parrots Rhychopsitta pachyrhyncha. Thick-billed Parrots are classified as 'Endangered' and their seasonal breeding range is restricted to increasingly fragmented and degraded high elevation mixed conifer forest habitat within the Sierra Madre Occidental region of north-western Mexico. Predation of established breeding pairs has recently contributed to the ongoing decline of Thick-billed Parrot populations by removing mature birds with high reproductive value, which has associated consequences for future recruitment. We observed increasing predation events on nesting Thick-billed Parrots by bobcats Lynx rufus accompanied by kittens throughout the 2018–2019 breeding seasons, and we speculate that recent reductions in bobcat habitat have pushed them into new ranges where they are supplementing their diet with nontraditional prey items. [ABSTRACT FROM AUTHOR]

Abstract The Canada lynx (Lynx canadensis) and the bobcat (Lynx rufus) are closely related species with overlap at their range peripheries, but the factors that limit each species and the interactions between them are not well understood. Habitat selection is a hierarchical process, in which selection at higher orders (geographic range, home range) may constrain selection at lower orders (within the home range). Habitat selection at a very fine scale within the home range has been less studied for both lynx and bobcat compared to selection at broader spatiotemporal scales. To compare this fourth‐order habitat selection by the two species in an area of sympatry, we tracked lynx and bobcat during the winters of 2017 and 2018 on the north shore of Lake Huron, Ontario. We found that both lynx and bobcat selected shallower snow, higher snowshoe hare abundance, and higher amounts of coniferous forest at the fourth order. However, the two species were spatially segregated at the second order, and lynx were found in areas with deeper snow, more snowshoe hare, and more coniferous forest. Taken together, our findings demonstrate that the lynx and bobcat select different resources at the second order, assorting along an environmental gradient in the study area, and that competition is unlikely to be occurring between the two species at finer scales.

Abstract Interspecific competition among carnivores has been linked to differences in behavior, morphology, and resource use. Insights into these interactions can enhance understanding of local ecological processes that can have impacts on the recovery of endangered species, such as the ocelot (Leopardus pardalis). Ocelots, bobcats (Lynx rufus), and coyotes (Canis latrans) share a small geographic range overlap from South Texas to south‐central Mexico but relationships among the three are poorly understood. From May 2011 to March 2018, we conducted a camera trap study to examine co‐occurrence patterns among ocelots, bobcats, and coyotes on the East Foundation's El Sauz Ranch in South Texas. We used a novel multiseason extension to multispecies occupancy models with ≥2 interacting species to conduct an exploratory analysis to examine interspecific interactions and examine the potential effects of patch‐level and landscape‐level metrics relative to the occurrence of these carnivores. We found strong evidence of seasonal mutual coexistence among all three species and observed a species‐specific seasonal trend in detection. Seasonal coexistence patterns were also explained by increasing distance from a high‐speed roadway. However, these results have important ecological implications for planning ocelot recovery in the rangelands of South Texas. This study suggests a coexistence among ocelots, bobcats, and coyotes under the environmental conditions on the El Sauz Ranch. Further research would provide a better understanding of the ecological mechanisms that facilitate coexistence within this community. As road networks in the region expand over the next few decades, large private working ranches will be needed to provide important habitat for ocelots and other carnivore species.

Harvest records suggest that the abundance of bobcats (Lynx rufus) has increased and the leading edge of their distribution has spread northward, while the trailing edge of the Canada lynx (Lynx canadensis) range has contracted in Ontario, Canada. There has been a debate about whether these closely related felids might compete in areas of sympatry, but there is little research on sympatric populations of bobcat and lynx. Both species are found on the north shore of Lake Huron in Ontario, Canada, which provided an opportunity to investigate their spatial patterns and habitat use. We surveyed snowmobile routes for snow tracks over three winters and estimated probability of occupancy for the two felid species while accounting for detectability. Bobcat and lynx tracks were never found on the same survey route. Bobcat occupancy increased with habitat heterogeneity, whereas lynx occupancy increased with homogeneity. Our results fit with the common assumption of the generalist and specialist natures of bobcat and lynx, respectively. Our findings suggest that bobcats invaded former lynx territory after these areas became vacant. The story of the bobcat and the lynx is one of the loss of a unique, boreal specialist due to anthropogenic change, and eventual replacement by an adaptable generalist.

Abstract The Great Lakes and the St. Lawrence River are imposing barriers for wildlife, and the additive effect of urban and agricultural development that dominates the lower Great Lakes region likely further reduces functional connectivity for many terrestrial species. As the climate warms, species will need to track climate across these barriers. It is important therefore to investigate land cover and bioclimatic hypotheses that may explain the northward expansion of species through the Great Lakes. We investigated the functional connectivity of a vagile generalist, the bobcat, as a representative generalist forest species common to the region. We genotyped tissue samples collected across the region at 14 microsatellite loci and compared different landscape hypotheses that might explain the observed gene flow or functional connectivity. We found that the Great Lakes and the additive influence of forest stands with either low or high canopy cover and deep lake‐effect snow have disrupted gene flow, whereas intermediate forest cover has facilitated gene flow. Functional connectivity in southern Ontario is relatively low and was limited in part by the low amount of forest cover. Pathways across the Great Lakes were through the Niagara region and through the Lower Peninsula of Michigan over the Straits of Mackinac and the St. Marys River. These pathways are important routes for bobcat range expansion north of the Great Lakes and are also likely pathways that many other mobile habitat generalists must navigate to track the changing climate. The extent to which species can navigate these routes will be important for determining the future biodiversity of areas north of the Great Lakes.

Abstract Over the past 20 years, the use of non‐invasive hair snare surveys in wildlife research and management has become more prevalent. While these tools have been used to answer important research questions, these techniques often fail to gather information on elusive carnivores, such as bobcats (Lynx rufus). Due to the limited success of previous bobcat studies using hair snares which required active rubbing, this technique has largely fallen out of use, in favor of camera trapping. The goal of our study was to construct a novel, passive bobcat hair snare that could be deployed regardless of terrain or vegetation features, which would be effective for use in capture–recapture population estimation at a large spatial scale. This new hair snare was deployed in 1500 10‐km2 cells across West Virginia (USA) between two sampling seasons (2015–2016). Collected hair samples were analyzed with newly developed mitochondrial DNA primers specifically for felids and qPCR to determine species of origin, with enough sensitivity to identify samples as small as two bobcat hairs. Over the two years of the study, a total of 378 bobcat detections were recorded from 42,000 trap nights of sampling, for an overall rate of 0.9 detections/100 trap nights—nearly 2–6 times greater than any previous bobcat hair snare study. While the overall number of recaptured animals was low (n = 9), continued development of this platform should increase its usefulness in capture–recapture studies.

Abstract Wildlife managers require defensible and transparent population estimates to justify species management. Statistical population reconstruction (SPR) is being widely adopted to estimate wildlife population sizes from hunter harvest data. We assessed factors influencing variation in SPR population estimates produced for bobcats in Wyoming, USA. Specifically, we tested whether prey availability, hunter/trapper effort, the number of bobcats killed or the methods used to classify the age and sex of bobcats (‘classification protocol’) best explained changing SPR abundance estimates. We then quantified the relative magnitude of these effects on SPR model outputs. Classification protocol had the strongest impact on SPR abundance estimates, such that a shift to visual age and sex classifications by trappers/hunters resulted in overestimates of bobcat abundance. The Wyoming bobcat SPR population estimates were likely unreliable and we suggest that spatially explicit integrated population models may be a better approach to obtaining defensible estimates upon which to establish scientific management of this charismatic carnivore.

Coexistence between humans and large carnivores may depend on carnivore adaptations to use developed landscapes while reducing human encounters. Roads are a widespread form of human development that carnivores may perceive as efficient travel routes or centers of human activity and associated risk. We compared the spatio-temporal responses of carnivores to human road use with high-resolution tracking of a large carnivore guild including American black bears (Ursus americanus), bobcats (Lynx rufus), coyotes (Canis latrans), and wolves (C. lupus) in Michigan, USA. All carnivores selected for roads when traveling at night but avoided roads during the day when human activity was greatest. Human activity explained 90% of temporal variation in road use across carnivore species, with a 3.2–3.7-fold increase in road use at times of low human activity which reduced carnivore activity overlap with humans by 27–42%. Similar but less pronounced activity changes occurred in areas up to 500 m from roads. Bears and wolves increased nocturnal activity with more roads in their home range, but not bobcats or coyotes. Despite increased diurnal activity in areas farther from roads, temporal overlap among carnivores was high regardless of road proximity. Our results suggest that spatio-temporal responses to roads were similar among carnivores and emphasized avoidance of humans over other carnivore species. Further, we provide support that carnivores can be diurnally active while avoiding humans by using areas farther from roads. However, carnivores which are primarily diurnal (e.g., black bears) or have a strong proclivity for using roads (e.g., wolves) likely require greater behavioral changes to avoid humans. Behavioral adaptations allowing multiple species to use and cross roads while avoiding humans are encouraging for human-carnivore coexistence.

Patterns of spatial genetic variation can be generated by a variety of ecological processes, including individual preferences based on habitat. These ecological processes act at multiple spatial and temporal scales, generating scale-dependent effects on gene flow. In this study, we focused on bobcats (Lynx rufus), a highly mobile, generalist felid that exhibits ecological and behavioral plasticity, high abundance, and broad connectivity across much of their range. However, bobcats also show genetic differentiation along habitat breaks, a pattern typically observed in cases of isolation-by-ecology (IBE). The IBE observed in bobcats is hypothesized to occur due to habitat-biased dispersal, but it is unknown if this occurs at other habitat breaks across their range or at what spatial scale IBE becomes most apparent. Thus, we used a multiscale approach to examine isolation by ecology (IBE) patterns in bobcats (Lynx rufus) at both fine and broad spatial scales in western Texas. We genotyped 102 individuals at nine microsatellite loci and used partial redundancy analysis (pRDA) to test if a suite of landscape variables influenced genetic variation in bobcats. Bobcats exhibited a latitudinal cline in population structure with a spatial signature of male-biased dispersal, and no clear barriers to gene flow. Our pRDA tests revealed high genetic similarity in similar habitats, and results differed by spatial scale. At the fine spatial scale, herbaceous rangeland was an important influence on gene flow whereas mixed rangeland and agriculture were significant at the broad spatial scale. Taken together, our results suggests that complex interactions between spatial-use behavior and landscape heterogeneity can create non-random gene flow in highly mobile species like bobcats. Furthermore, our results add to the growing body of data highlighting the importance of multiscale study designs when assessing spatial genetic structure.

Patterns of spatial genetic variation can be generated by a variety of ecological processes, including individual preferences based on habitat. These ecological processes act at multiple spatial and temporal scales, generating scale-dependent effects on gene flow. In this study, we focused on bobcats (Lynx rufus), a highly mobile, generalist felid that exhibits ecological and behavioral plasticity, high abundance, and broad connectivity across much of their range. However, bobcats also show genetic differentiation along habitat breaks, a pattern typically observed in cases of isolation-by-ecology (IBE). The IBE observed in bobcats is hypothesized to occur due to habitat-biased dispersal, but it is unknown if this occurs at other habitat breaks across their range or at what spatial scale IBE becomes most apparent. Thus, we used a multiscale approach to examine isolation by ecology (IBE) patterns in bobcats (Lynx rufus) at both fine and broad spatial scales in western Texas. We genotyped 102 individuals at nine microsatellite loci and used partial redundancy analysis (pRDA) to test if a suite of landscape variables influenced genetic variation in bobcats. Bobcats exhibited a latitudinal cline in population structure with a spatial signature of male-biased dispersal, and no clear barriers to gene flow. Our pRDA tests revealed high genetic similarity in similar habitats, and results differed by spatial scale. At the fine spatial scale, herbaceous rangeland was an important influence on gene flow whereas mixed rangeland and agriculture were significant at the broad spatial scale. Taken together, our results suggests that complex interactions between spatial-use behavior and landscape heterogeneity can create non-random gene flow in highly mobile species like bobcats. Furthermore, our results add to the growing body of data highlighting the importance of multiscale study designs when assessing spatial genetic structure. [ABSTRACT FROM AUTHOR]

Bobcats (Lynx rufus) have been increasing in abundance in the northeast United States despite a corresponding trend of increased anthropogenic land uses. Inhabiting areas of high human land use can affect stress levels, and hence cortisol titers, for wildlife species by increasing frequency of human interaction and altering habitats. In turn, increased cortisol levels can have negative effects at the individual and population level including decreased immune function, slowed growth and tissue repair, reduced reproductive capacity, and nutritional deficiencies. We quantified cortisol in bobcats across New Hampshire and Vermont, USA, using hair samples, then explored associations between hair cortisol and various organismal, land use, land cover, and climatic variables at 2 different spatial scales. Hair cortisol differed by season and bobcat mass. On average, cortisol levels were higher in fall than in spring, and larger bobcats had lower cortisol levels. Anthropogenic land uses—especially residential and agricultural uses—were the most important predictors of hair cortisol at the town scale (x̅ area = 93 km2). At a larger scale (Wildlife Management Units; x̅ area = 1,256 km2), temperature and precipitation were better predictors of hair cortisol, suggesting that extreme weather may have significant effects on bobcat population dynamics. Our results highlight the importance of landscape composition and local conditions in the sustainable management of furbearer populations. © 2021 The Wildlife Society. Hair cortisol levels in bobcats vary with land use types and climate variables at different scales. Taking these factors into account when determining harvest and management strategies may help limit negative effects of elevated chronic stress levels. [ABSTRACT FROM AUTHOR]

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Despite the increasing spatial, temporal and dietary overlap between bobcats Lynx rufus and coyotes Canis latrans, these species live sympatrically throughout much of North America. To determine if differential activity patterns relative to abiotic variables might influence interspecific interactions, we investigated whether these species responded differentially to crepuscular and nocturnal abiotic variables in Texas. Using GPS collars, we calculated hourly movements from sequential locations, and compared bobcat and coyote movements relative to sex, season, moonlight intensity, night period, crepuscularity and temperature. We used generalized linear mixed effects models (GLMM) to investigate the responses of bobcats and coyotes to variables associated to their nocturnal movements. Temperature and its interactions with various abiotic variables influenced bobcat movements. Biological season and its interactions with other abiotic variables influenced coyote movements. Bobcats moved shorter hourly distances than coyotes. Female bobcats moved shorter hourly distances than males. Moonlight intensity seemed to influence coyotes but not bobcats. Differential movements between bobcats and coyotes relative to night period could possibly be due behavioral avoidance of coyotes by bobcats. Reduced crepuscular activity by coyotes may be behavioral avoidance of humans. Differential responses to nocturnal variables may dampen competitive interactions between bobcats and coyotes. [ABSTRACT FROM AUTHOR]

A 15-year study of carnivores in an urban landscape in southern California has revealed a high incidence of exposure of non-target wildlife to anticoagulant rodenticides (ARs). All carnivore species studied, including mountain lions, coyotes, bobcats, and gray foxes, have tested positive for exposure to the toxicants. Anticoagulant residues have been detected in post-mortem liver samples at a rate of 83-93% of individuals tested, for coyotes, bobcats, and mountain lions, the three species for which we have extensive sampling. We have also documented mortalities caused directly by exposure to ARs in all four species, particularly in the canids. In both felid species, we found a positive correlation between AR exposure and mange disease, specifically notoedric mange. The incidence of fatal mange infection in bobcats has been at epizootic levels since 2002 in our study area, and more recently outbreaks of the disease have been documented in several other populations in California, all apparently (where testing has been done) in association with exposure to ARs. There are no previously reported instances of epizootics of notoedric mange in any wild felid population. Carnivore exposure to these toxicants appears to be largely secondary (or tertiary, as may be the case in mountain lions) through consumption of their natural prey. In our most recent work, we have evaluated AR exposure of carnivore prey species, including rodents and lagomorphs. We have documented exposure in ground squirrels and woodrats, both of which are regularly consumed by gray foxes, coyotes, and bobcats. Overall, we have found widespread exposure of non-target wildlife to these toxicants, with potentially significant consequences for some species.

Abstract Background Pine savannas are primarily managed with frequent prescribed fire (≤ 3 years) to promote diversity of flora and fauna, and to maintain open, park-like conditions needed by species such as the endangered red-cockaded woodpecker (Picoides borealis). However, a knowledge gap exists in our understanding of bobcat (Lynx rufus) habitat selection in longleaf pine savannas and research is warranted to direct our future management decisions. Methods We examined bobcat habitat selection in a pine savanna managed with frequent fires at two spatial scales (i.e., study area boundary [hereafter, landscape scale]) and annual area of use [95% kernel density; local scale]), and assessed effects of prescribed fire on bobcat habitat selection. Specifically, we monitored 45 bobcats (16 males and 29 females) during 2001–2007. Results We found differential habitat selection by sex. At the landscape scale, female bobcats were closer to mixed pine-hardwoods, young pine, and secondary roads, but farther from mature pine and hardwoods stands relative to males. We found no difference in selection of agriculture, shrub-scrub, and primary roads between sexes. At the annual area of use scale, female bobcats were closer to secondary roads, but farther from agriculture and shrub-scrub relative to males. We found no difference in selection of mature pine, mixed pine-hardwoods, hardwoods, young pine, and primary roads between sexes. Bobcats primarily selected for stands burned ≤ 1.1 years post-fire. Conclusions Our results show that bobcats exploit a broad range of habitat types in pine landscapes managed with frequent fire and commonly use recently burned stands (≤ 1.1 year post-fire), suggesting prey in many areas of this system are at risk of bobcat predation. Additionally, we suggest land managers consider scale of selection by bobcats when developing habitat management strategies.

Predator control to enhance avian reproductive success is a controversial issue in wildlife management, yet rarely is the effectiveness of this tool evaluated with respect to the impact it has on predator populations. Understanding predator demographic responses to intense predator reduction efforts has important applied implications, and provides data to answer to public scrutiny. Medium-sized, generalist mammals (i.e., meso-mammalian) are important nest predators of the declining gamebird, the northern bobwhite, and may limit bobwhite populations. To evaluate the effectiveness of intensive predator control on influencing meso-mammal populations, we monitored 4 primary meso-mammal nest predators of bobwhites. These species include raccoon, Virginia opossum, nine-banded armadillo, and bobcat. We used scent stations to monitor predators on 4 study sites (1,300-1,400 ha each) in northern Florida and southern Georgia during 2000-2006. Baseline data were collected in 2000 for all study sites. During 2001-2003, 2 sites received intensive meso-mammal predator reduction during the 7-month bobwhite breeding season, whereas the other two sites served as controls with no reduction occurring. After 3 years, the treatments were reversed. Using predator detection at scent stations, we modeled the probability that predators used 25-ha patches across the study sites via a community occupancy model. We examined the probability of patch use between years to determine the effectiveness of predator reduction and the resilience of predator populations to management. We removed a total of 5,161 meso-mammals from our study areas. Our results show meso-mammal predator control, as done on our study area, was sufficiently intensive enough to reduce predator use across target sites, but continued reduction would be needed to reduce predator patch use between years. Our findings demonstrate that a predator community can be reduced at the local scale; however, the predators remain on the greater landscape thereby minimizing potential for negative impacts on ecosystem integrity.

We address the comments made by Thornton et al. (Ecology and Evolution, 2019) in response to our recent article on measuring the agreement among experts in classifying camera images of bobcats and Canada lynx.

Latrines serve as important communication networks among felids for transmitting information relative to social dominance, reproductive status, and defense of hunting areas. During January 2011–August 2012, we monitored 10 bobcat (Lynx rufus) latrines in the northern Lower Peninsula (NLP) of Michigan, USA, using motion‐sensitive cameras to estimate bobcat visitation and scat deposition rates among 3 biological seasons (mating, kitten‐rearing, non‐mating). Bobcat visitation rates differed among the 3 seasons. We found equal number of visits during the mating and kitten‐rearing seasons, and lower visitation rates during the non‐mating season. Scat deposition rates differed among the 3 seasons. We found a net gain of scats deposited during the mating and non‐mating seasons, whereas there was a net loss of scats during the kitten‐rearing season. An artificial latrine protocol we developed yielded visitation at 4 of 12 artificial latrine sites. Monitoring natural and artificial latrines during the mating and kitten‐rearing seasons could provide valuable data for managing bobcat populations. © 2020 The Wildlife Society. Bobcats used latrines to advertise social status and reproductive status during the mating season and to mark hunting areas for return visits and defense of core hunting areas during the kitten‐rearing season. Monitoring latrines during these seasons could provide valuable data for managing bobcat populations. [ABSTRACT FROM AUTHOR]

Chemical immobilization is used to minimize stress and pain while safely handling wild animals under field conditions. Eight wild bobcats (Lynx rufus) were immobilized for radio collar fittings between March 2005 and March 2007, using a commercial tiletamine hydrochloride-zolazepam hydrochloride combination (Zoletil® Virbac, Carros, France). Bobcats were captured using soft catch spring traps (Victor No. 3) in the Sonoran Desert of Baja California Sur, Mexico. A mean (±SD) intramuscular total dose of 44.3 ± 2.9 mg (6.0 mg kg-1) produced an induction time of 9 ± 4.9 min, and a duration of cataleptic anesthesia of 46.5 ±11.4 min. No adverse reactions were observed in animals during handling, and telemetry monitoring indicated that all individuals were alive for at least one year after the procedure. The results of this study indicate that use of tiletamine-zolazepam administered at 6 mg/kg dose is suitable for short-term chemical immobilization of bobcats in the wild. [ABSTRACT FROM AUTHOR]

The Canada lynx (Lynx canadensis) and the bobcat (Lynx rufus) are closely related species with overlap at their range peripheries, but the factors that limit each species and the interactions between them are not well understood. Habitat selection is a hierarchical process, in which selection at higher orders (geographic range, home range) may constrain selection at lower orders (within the home range). Habitat selection at a very fine scale within the home range has been less studied for both lynx and bobcat compared to selection at broader spatiotemporal scales. To compare this fourth‐order habitat selection by the two species in an area of sympatry, we tracked lynx and bobcat during the winters of 2017 and 2018 on the north shore of Lake Huron, Ontario. We found that both lynx and bobcat selected shallower snow, higher snowshoe hare abundance, and higher amounts of coniferous forest at the fourth order. However, the two species were spatially segregated at the second order, and lynx were found in areas with deeper snow, more snowshoe hare, and more coniferous forest. Taken together, our findings demonstrate that the lynx and bobcat select different resources at the second order, assorting along an environmental gradient in the study area, and that competition is unlikely to be occurring between the two species at finer scales. [ABSTRACT FROM AUTHOR]