Diet selection in the Coyote Canis latrans

The Coyote (Canis latrans) is one of the most studied species in North America with at least 445 papers on its diet alone. While this research has yielded excellent reviews of what coyotes eat, it has been inadequate to draw deeper conclusions because no synthesis to date has considered prey availability. We accounted for prey availability by investigating the prey selection of coyotes across its distribution using the traditional Jacobs' index method, as well as the new iterative preference averaging (IPA) method on scats and biomass. We found that coyotes selected for Dall's Sheep (Ovis dalli), White-tailed Deer (Odocoileus virginianus), Eastern Cottontail Rabbit (Sylvilagus floridanus), and California Vole (Microtus californicus), which yielded a predator-to-preferred prey mass ratio of 1:2. We also found that coyotes avoided preying on other small mammals, including carnivorans and arboreal species. There was strong concordance between the traditional and IPA method on scats, but this pattern was weakened when biomass was considered. General linear models revealed that coyotes preferred to prey upon larger species that were riskier to hunt, reflecting their ability to hunt in groups, and were least likely to hunt solitary species. Coyotes increasingly selected Mule Deer (O. hemionus) and Snowshoe Hare (Lepus americanus) at higher latitudes, whereas Black-tailed Jackrabbit (L. californicus) were increasingly selected toward the tropics. Mule Deer were increasingly selected at higher coyote densities, while Black-tailed Jackrabbit were increasingly avoided at higher coyote densities. Coyote predation could constrain the realized niche of prey species at the distributional limits of the predator through their increased efficiency of predation reflected in increased prey selection values. These results are integral to improved understandings of Coyote ecology and can inform predictive analyses allowing for spatial variation, which ultimately will lead to better understandings about the ecological role of the coyote across different ecosystems.

Stress in the city? Coyote hair cortisol varies with intrinsic and extrinsic factors within a heavily urbanized landscape

Wildlife living in proximity to people are exposed to both natural and anthropogenic factors that may influence cortisol production associated with stress response. While some species, including coyotes (Canis latrans), have become commonplace in developed areas throughout North America, urban individuals still must navigate ever-changing, novel environments and cope with frequent disturbance. Given that coyotes are relatively large predators compared to most other urban wildlife, they face unique pressures such as crossing roadways to use suitable habitat fragments and are at a greater risk of being detected and experiencing negative human interactions. To assess whether urbanization influences hypothalamic-pituitary-adrenal axis activity in free-ranging coyotes, we analyzed cortisol concentration in hair samples from 97 coyotes residing across the urbanization gradient within the Greater Chicago Metropolitan area. As the proportion of developed landcover within coyote home ranges increased, coyotes experienced more stress. Body condition and social status also had strong relationships with stress. Animals in poorer body condition experienced more stress and subordinate coyotes experienced less stress than alphas. We also found some evidence that stress varied seasonally and among different age classes. Understanding how intrinsic and extrinsic factors influence endocrine activity in urban carnivores is vital for predicting how hormone production and related behavioral patterns may change in future populations as more areas become developed.

Changes in Fecal Glucocorticoid Metabolites in Captive Coyotes (Canis latrans): Influence of Gender, Time, and Reproductive Status

Reproduction is considered an energetically and physiologically demanding time in the life of an animal. Changes in physiological stress are partly reflected in changes in glucocorticoid metabolites and can be measured from fecal samples. We examined levels of fecal glucocorticoid metabolites (fGCMs) in 24 captive coyotes (Canis latrans) to investigate responses to the demands of reproduction. Using 12 pairs of coyotes (five pairs produced pups, seven pairs did not), we analyzed 633 fecal samples covering 11 biological periods (e.g., breeding, gestation, and lactation). Levels of fGCMs showed high individual variability, with females having higher fGCM levels than males. The production of pups showed no statistical effect on fGCM levels among females or males. Among females, fGCM levels were highest during 4-6 weeks of gestation compared to other periods but were not significantly different between pregnant and nonpregnant females. Among males, the highest fGCM levels were during 1-3 weeks of gestation compared to other periods, but were not significantly different between males with a pregnant mate versus nonpregnant mate. Of females producing pups, litter size did not influence fGCM levels. Given that they were fed ample food throughout the year, we found that the demands of producing pups did not appear to statistically influence measures of fGCM concentrations in captive coyotes.

Coursing the mottled mosaic: Generalist predators track pulses in availability of neonatal ungulates

The density and distribution of resources shape animal movement and behavior and have direct implications for population dynamics. Resource availability often is "pulsed" in space and time, and individuals should cue in on resource pulses when the energetic gain of doing so exceeds that of stable resources. Birth pulses of prey represent a profitable but ephemeral resource and should thereby result in shifting functional responses by predators. We evaluated movements and resource selection of coyotes (Canis latrans) across a gradient of reproductive stages ranging from late gestation to peak lactation of female mule deer (Odocoileus hemionus) in southwest Wyoming, USA, to test whether coyotes exhibited shifts in selection and movement behavior relative to the availability and vulnerability of neonatal mule deer. We expected coyotes to track pulses in availability of neonatal mule deer, and such behavior would be represented by shifts in resource selection and search behavior of coyotes that would be strongest during peak parturition of mule deer. Coyotes selected areas of high relative probability of use by female mule deer and did so most strongly during peak parturition. Furthermore, searching behavior of coyotes intensified during pulses of availability of deer neonates. Our findings support the notion that coyotes exploit pulses of neonatal deer, presumably as an attempt to capitalize on a vulnerable, energy-rich resource. Our work quantifies the behavioral mechanisms by which coyotes consume ungulate neonates and provides one of the first examples of a mammalian predator-prey system centered on a pulsed resource.

Can a traditional partner preference test quantify monogamous behavior in captive coyotes?

Social monogamy is a unique social system exhibited by only 3-5% of mammalian taxa; however, all wild canid species exhibit this social system. Despite the high prevalence of social monogamy among canids, little is known about how they form selective social attachment relationships among non-kin. Thus, we aimed to quantify monogamous behavior in a highly ubiquitous canid, the coyote (Canis latrans). We adapted the three-chambered partner preference test, which was originally developed for prairie voles (Microtus ochrogaster), to assess social preference in mated pairs of captive coyotes at the USDA Predator Research Facility. We quantified monogamy-related behaviors, such as time spent in spatial proximity to a pair-mate versus a stranger. Our behavioral ethogram also included visual seeking, olfactory investigations, ears down, scent marking, and affiliative behavior. Test subjects showed significantly greater affiliative behavior toward their partner than toward a stranger. However, there was extremely high variability both within and between coyote pairs across behavioral measures. These data suggest the need for larger sample sizes when working with species with high individual variability, as well as the need for species- and facility-specific modifications to this testing paradigm and/or ethogram to better adapt it from its laboratory and rodent-based origins.

Identification of antimicrobial resistance genes in intestinal content from Coyote (Canis latrans)

Antibiotic resistance has become a global public health concern in the last few years. Given the widespread rate of recurrence, increasing attention is being turned toward environmental pathways that potentially contribute to antibiotic resistance genes (ARGs) dissemination outside the clinical realm. In this study, a metagenome analysis of intestinal virus-like particle fraction (VLPs) from a wild coyote ( Canis latrans) revealed for the first time, multiple ARGs, such as B-lactamases and multidrug efflux pumps. Description of ARGs presence in natural environments is critical to understand the emergence of resistant strains.

Anthropogenic subsidies influence resource use during a mange epizootic in a desert coyote population

Colonization of urban areas by synanthropic wildlife introduces novel and complex alterations to established ecological processes, including the emergence and spread of infectious diseases. Aggregation at urban resources can increase disease transfer, with wide-ranging species potentially infecting outlying populations. The garrison at the National Training Center, Fort Irwin, California, USA, was recently colonized by mange-infected coyotes (Canis latrans) that also use the surrounding Mojave Desert. This situation provided an ideal opportunity to examine the effects of urban resources on disease dynamics. We evaluated seasonal space use and determined the influence of anthropogenic subsidies, water sources, and prey density on urban resource selection. We found no difference in home range size between healthy and infected individuals, but infected residents had considerably more spatial overlap with one another than healthy residents. All coyotes selected for anthropogenic subsidies during all seasons, while infected coyotes seasonally selected for urban water sources, and healthy coyotes seasonally selected for urban areas with greater densities of natural prey. These results suggest that while all coyotes were selecting for anthropogenic subsidies, infected resident coyotes demonstrated a greater tolerance for other conspecifics, which could be facilitating the horizontal transfer of sarcoptic mange to non-resident coyotes. Conversely, healthy coyotes also selected for natural prey and healthy residents exhibited a lack of spatial overlap with other coyotes suggesting they were not reliant on anthropogenic subsidies and were maintaining territories. Understanding the association between urban wildlife, zoonotic diseases, and urban resources can be critical in determining effective responses for mitigating future epizootics.

Molecular phylogeny supports invalidation of Didelphodiplostomum and Pharyngostomoides (Digenea: Diplostomidae) and reveals a Tylodelphys from mammals

Alaria, Didelphodiplostomum and Pharyngostomoides are among genera of diplostomid digeneans known to parasitize mammalian definitive hosts. Despite numerous recent molecular phylogenetic studies of diplostomids, limited DNA sequence data is available from diplostomids parasitic in mammals. Herein, we provide the first 28S rDNA and cox1 mtDNA sequences from morphologically identified, adult specimens of Didelphodiplostomum and Pharyngostomoides. Newly generated 28S sequences were used to infer the phylogenetic interrelationships of these two genera among other major lineages of diplostomoideans. The phylogeny based on 28S and a review of morphology clearly suggests that Pharyngostomoides should be considered a junior synonym of Alaria, while Didelphodiplostomum should be considered a junior synonym of Tylodelphys. Pharyngostomoides procyonis (type species), Pharyngostomoides adenocephala and Pharyngostomoides dasyuri were transferred into Alaria as Alaria procyonis comb. nov., Alaria adenocephala comb. nov. and Alaria dasyuri comb. nov.; Didelphodiplostomum variabile (type species) and Didelphodiplostomum nunezae were transferred into Tylodelphys as Tylodelphys variabilis comb. nov. and Tylodelphys nunezae comb. nov. In addition, Alaria ovalis comb. nov. (formerly included in Pharyngostomoides) was restored and transferred into Alaria based on a morphological study of well-fixed, adult specimens and the comparison of cox1 DNA sequences among Alaria spp. The diplostomid genus Parallelorchis was restored based on review of morphology.

Susceptibility of Wild Canids to SARS-CoV-2

We assessed 2 wild canid species, red foxes (Vulpes vulpes) and coyotes (Canis latrans), for susceptibility to SARS-CoV-2. After experimental inoculation, red foxes became infected and shed infectious virus. Conversely, experimentally challenged coyotes did not become infected; therefore, coyotes are unlikely to be competent hosts for SARS-CoV-2.

White-tailed deer exploit temporal refuge from multi-predator and human risks on roads

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.

Scavenging vs hunting affects behavioral traits of an opportunistic carnivore

Background

Human-induced changes to ecosystems transform the availability of resources to predators, including altering prey populations and increasing access to anthropogenic foods. Opportunistic predators are likely to respond to altered food resources by changing the proportion of food they hunt versus scavenge. These shifts in foraging behavior will affect species interactions through multiple pathways, including by changing other aspects of predator behavior such as boldness, innovation, and social structure.

Methods

To understand how foraging behavior impacts predator behavior, we conducted a controlled experiment to simulate hunting by introducing a prey model to captive coyotes (Canis latrans) and compared their behavior to coyotes that continued to scavenge over one year. We used focal observations to construct behavioral budgets, and conducted novel object, puzzle box, and conspecific tests to evaluate boldness, innovation, and response to conspecifics.

Results

We documented increased time spent resting by hunting coyotes paired with decreased time spent active. Hunting coyotes increased boldness and persistence but there were no changes in innovation. Our results illustrate how foraging behavior can impact other aspects of behavior, with potential ecological consequences to predator ecology, predator-prey dynamics, and human-wildlife conflict; however, the captive nature of our study limits specific conclusions related to wild predators. We conclude that human-induced behavioral changes could have cascading ecological implications that are not fully understood.

Fine-scale movements and behaviors of coyotes (Canis latrans) during their reproductive period

In canids, resident breeders hold territories but require different resources than transient individuals (i.e., dispersers), which may result in differential use of space, land cover, and food by residents and transients. In the southeastern United States, coyote (Canis latrans) reproduction occurs during spring and is energetically demanding for residents, but transients do not reproduce and therefore can exhibit feeding behaviors with lower energetic rewards. Hence, how coyotes behave in their environment likely differs between resident and transient coyotes. We captured and monitored 36 coyotes in Georgia during 2018-2019 and used data from 11 resident breeders, 12 predispersing residents (i.e., offspring of resident breeders), and 11 transients to determine space use, movements, and relationships between these behaviors and landcover characteristics. Average home range size for resident breeders and predispersing offspring was 20.7 ± 2.5 km² and 50.7 ± 10.0 km², respectively. Average size of transient ranges was 241.4 ± 114.5 km². Daily distance moved was 6.3 ± 3.0 km for resident males, 5.5 ± 2.7 km for resident females, and 6.9 ± 4.2 km for transients. We estimated first-passage time values to assess the scale at which coyotes respond to their environment, and used behavioral change-point analysis to determine that coyotes exhibited three behavioral states. We found notable differences between resident and transient coyotes in regard to how landcover characteristics influenced their behavioral states. Resident coyotes tended to select for areas with denser vegetation while resting and foraging, but for areas with less dense vegetation and canopy cover when walking. Transient coyotes selected areas closer to roads and with lower canopy cover while resting, but for areas farther from roads when foraging and walking. Our findings suggest that behaviors of both resident and transient coyotes are influenced by varying landcover characteristics, which could have implications for prey.

Early life experience influences dispersal in coyotes (Canis latrans)

Natal dispersal plays an important role in connecting individual animal behavior with ecological processes at all levels of biological organization. As urban environments are rapidly increasing in extent and intensity, understanding how urbanization influences these long distance movements is critical for predicting the persistence of species and communities. There is considerable variation in the movement responses of individuals within a species, some of which is attributed to behavioral plasticity which interacts with experience to produce interindividual differences in behavior. For natal dispersers, much of this experience occurs in the natal home range. Using data collected from VHF collared coyotes (Canis latrans) in the Chicago Metropolitan Area we explored the relationship between early life experience with urbanization and departure, transience, and settlement behavior. Additionally, we looked at how early life experience with urbanization influenced survival to adulthood and the likelihood of experiencing a vehicle related mortality. We found that coyotes with more developed habitat in their natal home range were more likely to disperse and tended to disperse farther than individuals with more natural habitat in their natal home range. Interestingly, our analysis produced mixed results for the relationship between natal habitat and habitat selection during settlement. Finally, we found no evidence that early life experience with urbanization influenced survival to adulthood or the likelihood of experiencing vehicular mortality. Our study provides evidence that early life exposure influences dispersal behavior; however, it remains unclear how these differences ultimately affect fitness.

Coyotes as Reservoirs for Onchocerca lupi, United States, 2015-2018

The Onchocerca lupi nematode infects dogs, cats, and humans, but whether it can be spread by coyotes has been unknown. We conducted surveillance for O. lupi nematode infection in coyotes in the southwestern United States. We identified multiple coyote populations in Arizona and New Mexico as probable reservoirs for this species.

Urbanization's influence on the distribution of mange in a carnivore revealed with multistate occupancy models

Increasing urbanization and use of urban areas by synanthropic wildlife has increased human and domestic animal exposure to zoonotic diseases and exacerbated epizootics within wildlife populations. Consequently, there is a need to improve wildlife disease surveillance programs to rapidly detect outbreaks and refine inferences regarding spatiotemporal disease dynamics. Multistate occupancy models can address potential shortcomings in surveillance programs by accounting for imperfect detection and the misclassification of disease states. We used these models to explore the relationship between urbanization, slope, and the spatial distribution of sarcoptic mange in coyotes (Canis latrans) inhabiting Fort Irwin, California, USA. We deployed remote cameras across 180 sites within the desert surrounding the populated garrison and classified sites by mange presence or absence depending on whether a symptomatic or asymptomatic coyote was photographed. Coyotes selected flatter sites closer to the urban area with a high probability of use (0.845, 95% credible interval (CRI): 0.728, 0.944); site use decreased as the distance to urban areas increased (standardized [Formula: see text] = - 1.354, 95% CRI - 2.423, - 0.619). The probability of correctly classifying mange presence at a site also decreased further from the urban area and was probably related to the severity of mange infection. Severely infected coyotes, which were more readily identified as symptomatic, resided closer to the urban area and were most likely dependent on urban resources for survival; urban resources probably contributed to sustaining the disease. Multistate occupancy models represent a flexible framework for estimating the occurrence and spatial extent of observable infectious diseases, which can improve wildlife disease surveillance programs.

Survey of coyotes, red foxes and wolves from Wyoming, USA, for Echinococcus granulosus s. l

The paraphyletic group Echinococcus granulosus sensu lato is comprised of parasitic tapeworms of wild and domestic canids such as wolves (Canis lupus) and coyotes (Canis latrans), which serve as definitive hosts, and ungulates, which are the intermediate hosts. Members of this tapeworm group are characterized by both cosmopolitan distribution and zoonotic disease potential. This survey (conducted from 2012 through 2017) was designed to provide insight into the prevalence and distribution of this parasite in wild canids in Wyoming. Echinococcus sp. infections were documented in 14 of 22 gray wolves (63.6%), 1 of 182 coyotes (0.55%) and 0 of 5 red foxes (Vulpes fulva). Echinococcus granulosus s. l. was confirmed in 4 of these 14 specimens obtained from wolves with two parasite specimens corresponding morphologically with E. canadensis (G8/G10). These results suggest that wolves serve as the major definitive host of E. granulosus s. l. in Wyoming, while coyotes do not play an equivalent role. Limited sample size precludes evaluation of the importance of the red fox as a favorable definitive host. Whereas this study documents the occurrence of E. granulosus s. l. in Wyoming, the zoonotic disease risk does not appear to be high. Education remains the key to disease prevention, coupled with good hygienic practices by humans and anthelmintic treatment of domestic dogs exhibiting elevated risk of exposure.

Rudimentary, "functionless" first metapodials of Canis latrans: Variation and association in length with longer, functional metapodials

A tenet of evolutionary theory is that phenotypic variation of a trait is inversely related to the intensity of stabilizing selection pressure. Among homologous bones, such as metapodials, a rudimentary, "nonfunctional" bone is expected to be more variable in length than nonrudimentary bones. This study compares variation and association in length among metapodials using 277 adult skeletons of Canis latrans. Canis latrans has a short, "functionless" first metacarpal (mc1) and "rudimentary, vestigial" first metatarsal (mt1). Results show that among the 10 metapodials, mt1 has the highest variation in length; other metapodials do not differ significantly from one another in their variation. Correlation coefficients for length of mc1 and mt1 with their ipsilateral metapodials 2-5 are significantly lower than coefficients for all other ipsilateral pairs. The correlation coefficient between left and right mt1 is significantly the lowest among all bilateral pairs of metapodials. Results are interpreted as follows. Mt1's high variation and low association in length are the outcome of less intense stabilizing selection pressure compared with other metapodials. The nonsignificant difference for variation in length between mc1 and metapodials 2-5 may be that mc1 is functional for development of a pollical dewclaw that helps restrain small prey.

Serologic Evidence for the Exposure of Eastern Coyotes (Canis latrans) in Pennsylvania to the Tick-Borne Pathogens Borreliella burgdorferi and Anaplasma phagocytophilum

The incidence of Lyme disease (Borreliella burgdorferi) and anaplasmosis (Anaplasma phagocytophilum) are increasing in North America and Europe. The causative agents of these debilitating tick-transmitted infections are maintained in nature in an enzootic cycle involving Ixodes ticks and diverse mammals and birds. It has been postulated that predators directly or indirectly influence the dynamics of the enzootic cycle and disease incidence. Here, we demonstrate high seropositivity of eastern coyotes for B. burgdorferi and A. phagocytophilum. As coyotes become established in urban and suburban environments, interactions with humans, companion animals, and urban/suburban wildlife will increase. Knowledge of the pathogens that these highly adaptable predators are exposed to or carry, and their potential to influence or participate in enzootic cycles, is central to efforts to reduce the risk of tick-borne diseases in humans and companion animals.

Lyme disease and anaplasmosis are tick-borne bacterial diseases caused by Borreliella and Anaplasma species, respectively. A comprehensive analysis of the exposure of eastern coyotes (Canis latrans) in the northeastern United States to tick-borne pathogens has not been conducted. In this report, we assess the serological status of 128 eastern coyotes harvested in Pennsylvania in 2015 and 2017 for antibodies to Borreliella burgdorferi and Anaplasma phagocytophilum. Immunoblot and dot blot approaches were employed to test each plasma sample by using cell lysates and recombinant proteins as detection antigens. The results demonstrate high seropositivity incidences of 64.8% and 72.7% for B. burgdorferi and A. phagocytophilum, respectively. Antibodies to both pathogens were detected in 51.5% of the plasma samples, indicating high potential for coinfection. Antibodies to the B. burgdorferi proteins DbpB, VlsE, DbpA, BBA36, and OspF (BBO39) were detected in 67.2, 63.3, 56.2, 51.6, and 48.4% of the plasma samples, respectively. Antibodies to the A. phagocytophilum P44 and P130 proteins were detected in 72.7 and 60.9% of the plasma samples, respectively.

IMPORTANCE The incidence of Lyme disease (Borreliella burgdorferi) and anaplasmosis (Anaplasma phagocytophilum) are increasing in North America and Europe. The causative agents of these debilitating tick-transmitted infections are maintained in nature in an enzootic cycle involving Ixodes ticks and diverse mammals and birds. It has been postulated that predators directly or indirectly influence the dynamics of the enzootic cycle and disease incidence. Here, we demonstrate high seropositivity of eastern coyotes for B. burgdorferi and A. phagocytophilum. As coyotes become established in urban and suburban environments, interactions with humans, companion animals, and urban/suburban wildlife will increase. Knowledge of the pathogens that these highly adaptable predators are exposed to or carry, and their potential to influence or participate in enzootic cycles, is central to efforts to reduce the risk of tick-borne diseases in humans and companion animals.

Responses of sympatric canids to human development revealed through citizen science

Measuring wildlife responses to anthropogenic activities often requires long-term, large-scale datasets that are difficult to collect. This is particularly true for rare or cryptic species, which includes many mammalian carnivores. Citizen science, in which members of the public participate in scientific work, can facilitate collection of large datasets while increasing public awareness of wildlife research and conservation. Hunters provide unique benefits for citizen science given their knowledge and interest in outdoor activities. We examined how anthropogenic changes to land cover impacted relative abundance of two sympatric canids, coyote (Canis latrans), and red fox (Vulpes vulpes) at a large spatial scale. In order to assess how land cover affected canids at this scale, we used citizen science data from bow hunter sighting logs collected throughout New York State, USA, during 2004-2017. We found that the two species had contrasting responses to development, with red foxes positively correlated and coyotes negatively correlated with the percentage of low-density development. Red foxes also responded positively to agriculture, but less so when agricultural habitat was fragmented. Agriculture provides food and denning resources for red foxes, whereas coyotes may select forested areas for denning. Though coyotes and red foxes compete in areas of sympatry, we did not find a relationship between species abundance, likely a consequence of the coarse spatial resolution used. Red foxes may be able to coexist with coyotes by altering their diets and habitat use, or by maintaining territories in small areas between coyote territories. Our study shows the value of citizen science, and particularly hunters, in collection of long-term data across large areas (i.e., the entire state of New York) that otherwise would unlikely be obtained.

Spatial variation in diet-microbe associations across populations of a generalist North American carnivore

Generalist species, by definition, exhibit variation in niche attributes that promote survival in changing environments. Increasingly, phenotypes previously associated with a species, particularly those with wide or expanding ranges, are dissolving and compelling greater emphasis on population-level characteristics. In the present study, we assessed spatial variation in diet characteristics, gut microbiome and associations between these two ecological traits across populations of coyotes Canis latrans. We highlight the influence of the carnivore community in shaping these relationships, as the coyote varied from being an apex predator to a subordinate, mesopredator across sampled populations. We implemented a scat survey across three distinct coyote populations in Michigan, USA. We used carbon (δ¹³ C) and nitrogen (δ¹⁵ N) isotopic values to reflect consumption patterns and trophic level, respectively. Corresponding samples were also paired with 16S rRNA sequencing to describe the microbial community and correlate with isotopic values. Although consumption patterns were comparable, we found spatial variation in trophic level among coyote populations. Specifically, δ¹⁵ N was highest where coyotes were the apex predator and lowest where coyotes co-occurred with grey wolves Canis lupus. The gut microbial community exhibited marked spatial variation across populations with the lowest operational taxonomic units diversity found where coyotes occurred at their lowest trophic level. Bacteriodes and Fusobacterium dominated the microbiome and were positively correlated across all populations. We found no correlation between δ¹³ C and microbial community attributes. However, positive associations between δ¹⁵ N and specific microbial genera increased as coyotes ascended trophic levels. Coyotes provide a model for exploring implications of niche plasticity because they are a highly adaptable, wide-ranging omnivore. As coyotes continue to vary in trophic position and expand their geographic range, we might expect increased divergence within their microbial community, changes in physiology and alterations in behaviour.

Co-occurrence of bobcats, coyotes, and ocelots in Texas

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.

Coyote (Canis latrans) in South America: potential routes of colonization

During the last century, the coyote (Canis latrans) has increased its distribution in Central America. Before the 1980s, it had not been recorded in Panama. New records show that coyotes have crossed the Panama Canal, indicating that continues to expand; therefore, there is a possibility that it will reach northern South America. Our objectives were to identify potential coyote colonization routes to South America, and the variables that favor its expansion. We hypothesized that habitat fragmentation benefits coyote expansion. We applied 7 algorithms to model the potential distribution of the coyote, using 196 presence records and 12 variables. The models with better performance were used to generate a consensus model. Using our consensus model and the areas with highest probability of presence, a potential colonization route was generated between Central America and northern South America. This route lies through southern Costa Rica, along the Pacific coast of Panama to the south, to the Andean mountains in northern Colombia. The variables that explained potential coyote distribution were human population density, altitude, and percentage of crops with positive influence, and tropical broadleaf forests with negative influence. These results indicate that human activities and deforestation are related to coyote distribution expansion. Actions can be implemented within the identified route to improve environmental management, in order to avoid the presence of the coyote in the ecosystems of northern South America.

The howl of Rancho La Brea: Comparative anatomy of modern and fossil canid hyoid bones

The Rancho La Brea (RLB) fossil collection housed at the La Brea Tar Pits and Museum in Los Angeles, California, is one of the richest collections of carnivoran fossils in the world. The collection is also particularly well known for the preservation of rare and understudied bones in the tar, including the small bony apparatus that is of particular interest to this study, the hyoid. The La Brea collection houses hyoids from several extinct carnivoran species, some of the most common being those of Canis dirus (the dire wolf) and Canis latrans (the coyote). In this study, we compare fossilized hyoid elements from these two canids to samples from modern large congeners, namely: Canis lupus (the gray wolf), Canis rufus (the red wolf), and modern C. latrans. Seven or nine measurements were taken on each bone of the hyoid apparatus, and principal component analyses were performed in order to determine statistical significance between species. For most of the bones, the majority of the variation was driven by size. Dire wolves could be clearly differentiated from all other canids for all elements; the hyoid apparatus of C. dirus is larger and more robust than that of C. lupus. Most of the bony elements could not be distinguished between red wolves or modern coyotes. However, there are enough, complete fossil coyote basihyoids to compare with those of their modern relatives, and in several metrics (both PC shapes and overall size), RLB and modern C. latrans are significantly different. As larger hyoids have been associated with a lower vocal frequency, this distinction would have resulted in the vocalizations of C. dirus occurring at a lower frequency than those produced by C. lupus and perhaps lower vocalizations in ice age coyotes than their modern relatives. RESEARCH HIGHLIGHTS: We quantify morphological differences in the hyoid of dire wolves (Canis dirus) relative to extant grey wolves (Canis lupus), and hypothesize that, as larger hyoids have been associated with a lower vocal frequency, the vocalizations of C. dirus might have occurred at a lower frequency than those by C. lupus. Likewise, modern and fossil coyotes (Canis latrans) show a significant difference in basihyoid size and shape, potentially indicating that modern and ancient coyotes might have sounded differently.

COYOTES (CANIS LATRANS) IN ARIZONA, USA, EXHIBIT IMMUNE AND GENETIC EVIDENCE OF RICKETTSIAL INFECTIONS

Rocky Mountain spotted fever (RMSF), caused by the bacterium Rickettsia rickettsii, was recognized as endemic in Arizona, US after a 2002 outbreak and has since been a public health concern. The brown dog tick (Rhipicephalus sanguineus sensu lato) is the principal vector of this pathogen in Arizona. Domesticated dogs (Canis lupus familiaris) are the tick's main host, so free-roaming dogs in peridomestic areas have been named the primary risk factor for human cases of RMSF. However, the sudden emergence and long-distance dispersal of the pathogen have not been adequately explained, and one possible mechanism could include wildlife. Coyotes (Canis latrans) are wide ranging in Arizona and closely related to dogs, so it is possible that brown dog ticks parasitize coyotes and infect them. Although R. rickettsii is the most severe spotted fever group (SFG) rickettsial pathogen in humans, others occur in Arizona, and antibodies raised against them are cross-reactive, so we more-broadly hypothesized that coyotes in Arizona are exposed to SFG rickettsiae. We collected coyote tissues in spring 2016 and 2017. We tested sera for antibodies to R. rickettsii and found 9% (8/94) of samples were antibody-positive with titers of ≥256. Subsequent quantitative PCR analyses of skin showed evidence for Rickettsia spp. in 2.9% (4/138) of samples. These data suggest that coyotes have a role in the maintenance of SFG rickettsiae in Arizona. Further investigation is warranted to reveal which specific pathogen-vector complexes act on coyotes in the region and whether they represent a risk to human health.

Endozoochorous dispersal of forest seeds by carnivorous mammals in Sierra Fría, Aguascalientes, Mexico

Some carnivorous mammals ingest fruit and disperse seeds of forest plant species capable of colonizing disturbed areas in ecosystems. The objective of the present study was to evaluate the dissemination of Arctostaphylos pungens and Juniperus deppeana seeds by the gray fox (Urocyon cinereoargenteus), coyote (Canis latrans), and other carnivores in the Protected Natural Area Sierra Fría, in Aguascalientes, Mexico. Scat collection was undertaken via transects using the direct search method, while the seasonal phenology of A. pungens and J. deppeana was evaluated by recording flower and fruit abundance on both the plant and the surrounding forest floor ground. Seed viability was assessed by optical densitometry via X-ray and a germination test. It was found that the gray fox, coyote, ringtail (Bassariscus astutus), and bobcat (Lynx rufus) disseminated seeds of A. pungens (212 ± 48.9 seeds/scat) and J. deppeana (23.6 ± 4.9 seeds/scat), since a large proportion of the collected scat of these species contained seeds (28/30 = 93.33%, 12/43 = 27.9%, 6/12 = 50% and 7/25 = 28% respectively). The gray fox, coyote, ringtail, and bobcat presented an average of seed dispersion of both plant species of 185.4 ± 228.7, 4.0 ± 20.0, 12.1 ± 30.4, and 0.8 ± 1.5 per scat; the seed proportions in the gray fox, coyote, ringtail, and bobcat were 89.6/10.4%, 82.3/17.7%, 90.4/9.6%, and 38.1/61.9% for A. pungens and J. deppeana, respectively. The phenology indicated a finding related to the greater abundance of ripe fruit in autumn and winter (p < .01). This coincided with the greater abundance of seeds found in scats during these seasons. Endozoochory and diploendozoochory enhanced the viability and germination of the seeds (p > .05), except in those of A. pungens dispersed by coyote. These results suggest that carnivores, particularly the gray fox, the coyote, and the bobcat, play an important role in forest seed dissemination, and thus forest regeneration, by making both a quantitative and qualitative contribution to the dispersal of the two pioneer species under study.

Influence of body mass and environmental conditions on winter mortality risk of a northern ungulate: Evidence for a late-winter survival bottleneck

A relationship between winter weather and survival of northern ungulates has long been established, yet the possible roles of biological (e.g., nutritional status) and environmental (e.g., weather) conditions make it important to determine which potential limiting factors are most influential.Our objective was to examine the potential effects of individual (body mass and age) and extrinsic (winter severity and snowmelt conditions) factors on the magnitude and timing of mortality for adult (>2.5 years old) female white-tailed deer (Odocoileus virginianus [Zimmerman, 1780]) during February-May in the Upper Peninsula of Michigan, USA.One hundred and fifty deer were captured and monitored during 2009-2015 in two areas with varying snowfall. February-May survival ranged from 0.24 to 0.89 (mean = 0.69) across years. Mortality risk increased 1.9% with each unit increase in cumulative winter severity index, decreased 8.2% with each cumulative snow-free day, and decreased 4.3% with each kg increase in body mass. Age and weekly snow depth did not influence weekly deer survival. Predation, primarily from coyote (Canis latrans [Say, 1823]) and wolves (Canis lupus [L., 1758]), accounted for 78% of known-cause mortalities.Our results suggest that cumulative winter severity, and possibly to a lesser degree deer condition entering winter, impacted deer winter survival. However, the timing of spring snowmelt appeared to be the most influential factor determining late-winter mortality of deer in our study. This supports the hypothesis that nutrition and energetic demands from weather conditions are both important to northern ungulate winter ecology. Under this model, a delay of several weeks in the timing of spring snowmelt could exert a large influence on deer survival, resulting in a survival bottleneck.

Echinococcus multilocularis Infection, Southern Ontario, Canada

Alveolar echinococcosis, the disease caused by infection with the intermediate stage of the Echinococcus multilocularis tapeworm, is typically fatal in humans and dogs when left untreated. Since 2012, alveolar echinococcosis has been diagnosed in 5 dogs, 3 lemurs, and 1 chipmunk in southern Ontario, Canada, a region previously considered free of these tapeworms. Because of human and animal health concerns, we estimated prevalence of infection in wild canids across southern Ontario. During 2015–2017, we collected fecal samples from 460 wild canids (416 coyotes, 44 foxes) during postmortem examination and analyzed them by using a semiautomated magnetic capture probe DNA extraction and real-time PCR method for E. multilocularis DNA. Surprisingly, 23% (95% CI 20%–27%) of samples tested positive. By using a spatial scan test, we identified an infection cluster (relative risk 2.26; p = 0.002) in the western-central region of the province. The cluster encompasses areas of dense human population, suggesting zoonotic transmission.

Geographic patterns in morphometric and genetic variation for coyote populations with emphasis on southeastern coyotes

Prior to 1900, coyotes (Canis latrans) were restricted to the western and central regions of North America, but by the early 2000s, coyotes became ubiquitous throughout the eastern United States. Information regarding morphological and genetic structure of coyote populations in the southeastern United States is limited, and where data exist, they are rarely compared to those from other regions of North America. We assessed geographic patterns in morphology and genetics of coyotes with special consideration of coyotes in the southeastern United States. Mean body mass of coyote populations increased along a west-to-east gradient, with southeastern coyotes being intermediate to western and northeastern coyotes. Similarly, principal component analysis of body mass and linear body measurements suggested that southeastern coyotes were intermediate to western and northeastern coyotes in body size but exhibited shorter tails and ears from other populations. Genetic analyses indicated that southeastern coyotes represented a distinct genetic cluster that differentiated strongly from western and northeastern coyotes. We postulate that southeastern coyotes experienced lower immigration from western populations than did northeastern coyotes, and over time, genetically diverged from both western and northeastern populations. Coyotes colonizing eastern North America experienced different selective pressures than did stable populations in the core range, and we offer that the larger body size of eastern coyotes reflects an adaptation that improved dispersal capabilities of individuals in the expanding range.

Parental habituation to human disturbance over time reduces fear of humans in coyote offspring

A fundamental tenet of maternal effects assumes that maternal variance over time should have discordant consequences for offspring traits across litters. Yet, seldom are parents observed across multiple reproductive bouts, with few studies considering anthropogenic disturbances as an ecological driver of maternal effects. We observed captive coyote (Canis latrans) pairs over two successive litters to determine whether among‐litter differences in behavior (i.e., risk‐taking) and hormones (i.e., cortisol and testosterone) corresponded with parental plasticity in habituation. Thus, we explicitly test the hypothesis that accumulating experiences of anthropogenic disturbance reduces parental fear across reproductive bouts, which should have disparate phenotypic consequences for first‐ and second‐litter offspring. To quantify risk‐taking behavior, we used foraging assays from 5–15 weeks of age with a human observer present as a proxy for human disturbance. At 5, 10, and 15 weeks of age, we collected shaved hair to quantify pup hormone levels. We then used a quantitative genetic approach to estimate heritability, repeatability, and between‐trait correlations. We found that parents were riskier (i.e., foraged more frequently) with their second versus first litters, supporting our prediction that parents become increasingly habituated over time. Second‐litter pups were also less risk‐averse than their first‐litter siblings. Heritability for all traits did not differ from zero (0.001–0.018); however, we found moderate support for repeatability in all observed traits (r = 0.085–0.421). Lastly, we found evidence of positive phenotypic and cohort correlations among pup traits, implying that cohort identity (i.e., common environment) contributes to the development of phenotypic syndromes in coyote pups. Our results suggest that parental habituation may be an ecological cue for offspring to reduce their fear response, thus emphasizing the role of parental plasticity in shaping their pups’ behavioral and hormonal responses toward humans.

Mapping the expansion of coyotes (Canis latrans) across North and Central America

The geographic distribution of coyotes (Canislatrans) has dramatically expanded since 1900, spreading across much of North America in a period when most other mammal species have been declining. Although this considerable expansion has been well documented at the state/provincial scale, continent-wide descriptions of coyote spread have portrayed conflicting distributions for coyotes prior to the 1900s, with popularly referenced anecdotal accounts showing them restricted to the great plains, and more obscure, but data-rich accounts suggesting they ranged across the arid west. To provide a scientifically credible map of the coyote’s historical range (10,000–300 BP) and describe their range expansion from 1900 to 2016, we synthesized archaeological and fossil records, museum specimens, peer-reviewed reports, and records from wildlife management agencies. Museum specimens confirm that coyotes have been present in the arid west and California throughout the Holocene, well before European colonization. Their range in the late 1800s was undistinguishable from earlier periods, and matched the distribution of non-forest habitat in the region. Coyote expansion began around 1900 as they moved north into taiga forests, east into deciduous forests, west into costal temperate rain forests, and south into tropical rainforests. Forest fragmentation and the extirpation of larger predators probably enabled these expansions. In addition, hybridization with wolves (C.lupus, C.lycaon, and/or C.rufus) and/or domestic dogs has been documented in the east, and suspected in the south. Our detailed account of the original range of coyotes and their subsequent expansion provides the core description of a large scale ecological experiment that can help us better understand the predator-prey interactions, as well as evolution through hybridization.

Size-assortative choice and mate availability influences hybridization between red wolves (Canis rufus) and coyotes (Canis latrans)

Anthropogenic hybridization of historically isolated taxa has become a primary conservation challenge for many imperiled species. Indeed, hybridization between red wolves (Canis rufus) and coyotes (Canis latrans) poses a significant challenge to red wolf recovery. We considered seven hypotheses to assess factors influencing hybridization between red wolves and coyotes via pair‐bonding between the two species. Because long‐term monogamy and defense of all‐purpose territories are core characteristics of both species, mate choice has long‐term consequences. Therefore, red wolves may choose similar‐sized mates to acquire partners that behave similarly to themselves in the use of space and diet. We observed multiple factors influencing breeding pair formation by red wolves and found that most wolves paired with similar‐sized conspecifics and wolves that formed congeneric pairs with nonwolves (coyotes and hybrids) were mostly female wolves, the smaller of the two sexes. Additionally, we observed that lower red wolf abundance relative to nonwolves and the absence of helpers increased the probability that wolves consorted with nonwolves. However, successful pairings between red wolves and nonwolves were associated with wolves that maintained small home ranges. Behaviors associated with territoriality are energetically demanding and behaviors (e.g., aggressive interactions, foraging, and space use) involved in maintaining territories are influenced by body size. Consequently, we propose the hypothesis that size disparities between consorting red wolves and coyotes influence positive assortative mating and may represent a reproductive barrier between the two species. We offer that it may be possible to maintain wild populations of red wolves in the presence of coyotes if management strategies increase red wolf abundance on the landscape by mitigating key threats, such as human‐caused mortality and hybridization with coyotes. Increasing red wolf abundance would likely restore selection pressures that increase mean body and home‐range sizes of red wolves and decrease hybridization rates via reduced occurrence of congeneric pairs.

Fatal Attraction? Intraguild Facilitation and Suppression among Predators

Competition and suppression are recognized as dominant forces that structure predator communities. Facilitation via carrion provisioning, however, is a ubiquitous interaction among predators that could offset the strength of suppression. Understanding the relative importance of these positive and negative interactions is necessary to anticipate community-wide responses to apex predator declines and recoveries worldwide. Using state-sponsored wolf (Canis lupus) control in Alaska as a quasi experiment, we conducted snow track surveys of apex, meso-, and small predators to test for evidence of carnivore cascades (e.g., mesopredator release). We analyzed survey data using an integrative occupancy and structural equation modeling framework to quantify the strengths of hypothesized interaction pathways, and we evaluated fine-scale spatiotemporal responses of nonapex predators to wolf activity clusters identified from radio-collar data. Contrary to the carnivore cascade hypothesis, both meso- and small predator occupancy patterns indicated guild-wide, negative responses of nonapex predators to wolf abundance variations at the landscape scale. At the local scale, however, we observed a near guild-wide, positive response of nonapex predators to localized wolf activity. Local-scale association with apex predators due to scavenging could lead to landscape patterns of mesopredator suppression, suggesting a key link between occupancy patterns and the structure of predator communities at different spatial scales.

Ungulate predation and ecological roles of wolves and coyotes in eastern North America

Understanding the ecological roles of species that influence ecosystem processes is a central goal of ecology and conservation biology. Eastern coyotes (Canis latrans) have ascended to the role of apex predator across much of eastern North America since the extirpation of wolves (Canis spp.) and there has been considerable confusion regarding their ability to prey on ungulates and their ecological niche relative to wolves. Eastern wolves (C. lycaon) are thought to have been the historical top predator in eastern deciduous forests and have previously been characterized as deer specialists that are inefficient predators of moose because of their smaller size relative to gray wolves (C. lupus). We investigated intrinsic and extrinsic influences on per capita kill rates of white-tailed deer (Odocoileus virginianus) and moose (Alces alces) during winter by sympatric packs of eastern coyotes, eastern wolves, and admixed canids in Ontario, Canada to clarify the predatory ability and ecological roles of the different canid top predators of eastern North America. Eastern coyote ancestry within packs negatively influenced per capita total ungulate (deer and moose combined) and moose kill rates. Furthermore, canids in packs dominated by eastern coyote ancestry consumed significantly less ungulate biomass and more anthropogenic food than packs dominated by wolf ancestry. Similar to gray wolves in previous studies, eastern wolves preyed on deer where they were available. However, in areas were deer were scarce, eastern wolves killed moose at rates similar to those previously documented for gray wolves at comparable moose densities across North America. Eastern coyotes are effective deer predators, but their dietary flexibility and low kill rates on moose suggest they have not replaced the ecological role of wolves in eastern North America.

High Trypanosoma cruzi infection prevalence associated with minimal cardiac pathology among wild carnivores in central Texas

Infection with the zoonotic vector-borne protozoal parasite Trypanosoma cruzi causes Chagas disease in humans and dogs throughout the Americas. Despite the recognized importance of various wildlife species for perpetuating Trypanosoma cruzi in nature, relatively little is known about the development of cardiac disease in infected wildlife. Using a cross-sectional study design, we collected cardiac tissue and blood from hunter-donated wildlife carcasses- including raccoon (Procyon lotor), coyote (Canis latrans), gray fox (Urocyon cinereoargenteus), and bobcat (Lynx rufus) - from central Texas, a region with established populations of infected triatomine vectors and increasing diagnoses of Chagas disease in domestic dogs. Based on PCR analysis, we found that 2 bobcats (14.3%), 12 coyotes (14.3%), 8 foxes (13.8%), and 49 raccoons (70.0%) were positive for T. cruzi in at least one sample (right ventricle, apex, and/or blood clot). Although a histologic survey of right ventricles showed that 21.1% of 19 PCR-positive hearts were characterized by mild lymphoplasmocytic infiltration, no other lesions and no amastigotes were observed in any histologic section. DNA sequencing of the TcSC5D gene revealed that raccoons were infected with T. cruzi strain TcIV, and a single racoon harbored a TcI/TcIV mixed infection. Relative to other wildlife species tested here, our data suggest that raccoons may be important reservoirs of TcIV in Texas and a source of infection for indigenous triatomine bugs. The overall high level of infection in this wildlife community likely reflects high levels of vector contact, including ingestion of bugs. Although the relationship between the sylvatic cycle of T. cruzi transmission and human disease risk in the United States has yet to be defined, our data suggest that hunters and wildlife professionals should take precautions to avoid direct contact with potentially infected wildlife tissues.

Influence of free water availability on a desert carnivore and herbivore

Anthropogenic manipulation of finite resources on the landscape to benefit individual species or communities is commonly employed by conservation and management agencies. One such action in arid regions is the construction and maintenance of water developments (i.e., wildlife guzzlers) adding free water on the landscape to buttress local populations, influence animal movements, or affect distributions of certain species of interest. Despite their prevalence, the utility of wildlife guzzlers remains largely untested. We employed a before-after control-impact (BACI) design over a 4-year period on the US Army Dugway Proving Ground, Utah, USA, to determine whether water availability at wildlife guzzlers influenced relative abundance of black-tailed jackrabbits Lepus californicus and relative use of areas near that resource by coyotes Canis latrans, and whether coyote visitations to guzzlers would decrease following elimination of water. Eliminating water availability at guzzlers did not influence jackrabbit relative abundance. Coyote relative use was impacted by water availability, with elimination of water reducing use in areas associated with our treatment, but not with areas associated with our control. Visitations of radio-collared coyotes to guzzlers declined nearly 3-fold following elimination of water. Our study provides the first evidence of a potential direct effect of water sources on a mammalian carnivore in an arid environment, but the ecological relevance of our finding is debatable. Future investigations aimed at determining water effects on terrestrial mammals could expand on our findings by incorporating manipulations of water availability, obtaining absolute estimates of population parameters and vital rates and incorporating fine-scale spatiotemporal data.

Poor health is associated with use of anthropogenic resources in an urban carnivore

Rates of encounters between humans and wildlife are increasing in cities around the world, especially when wildlife overlap with people in time, space and resources. Coyotes (Canis latrans) can make use of anthropogenic resources and reported rates of conflict have increased in cities across North America. This increase may be linked to individual differences in the use of human food and developed areas. We compared the relationships between coyote age, sex or health and the use of anthropogenic resources, which we defined as using developed areas over large home ranges, being active during the day, and consuming anthropogenic food. To do so, we applied GPS collars to 19 coyotes and sampled hair for stable isotope analysis. Eleven coyotes appeared to be healthy and eight were visibly infested with sarcoptic mange (Sarcoptes scabiei), a mite that causes hair loss. Diseased coyotes used more developed areas, had larger monthly home ranges, were more active during the day, and assimilated less protein than coyotes that appeared to be healthy. We speculate that anthropogenic food provides a low-quality but easily accessible food source for diseased coyotes, which in turn may increase reliance on it and other anthropogenic resources to promote encounters with people.

Mitochondrial DNA Variation in Southeastern Pre-Columbian Canids

The taxonomic status of the red wolf (Canis rufus) is heavily debated, but could be clarified by examining historic specimens from the southeastern United States. We analyzed mitochondrial DNA (mtDNA) from 3 ancient (350-1900 year olds) putative wolf samples excavated from middens and sinkholes within the historic red wolf range. We detected 3 unique mtDNA haplotypes, which grouped with the coyote mtDNA clade, suggesting that the canids inhabiting southeastern North America prior to human colonization from Europe were either coyotes, which would vastly expand historic coyote distributions, an ancient coyote-wolf hybrid, or a North American evolved red wolf lineage related to coyotes. Should the red wolf prove to be a distinct species, our results support the idea of either an ancient hybrid origin for red wolves or a shared common ancestor between coyotes and red wolves.

Nutritional effects on reproductive performance of captive adult female coyotes (Canis latrans)

Interactions between animals and their environment are fundamental to ecological research. Field studies of coyote (Canis latrans) reproductive performance suggest mean litter size changes in response to prey abundance. However, this relationship has been assessed primarily by using carcasses collected from trappers. The objective of this study was to assess whether nutritional manipulation prior to mating affected reproduction in adult female coyotes. We examined the effects of caloric restriction during the 7 months prior to estrus on the reproductive rates of 11 captive female coyotes and the subsequent initial survival of pups through two reproductive cycles. This was a 2-year study with a cross-over design so each female was monitored for reproductive performance on each of the two diet treatments. We assessed the number of implantation scars, number of pups born, sex ratios of pups, average pup weight at birth and 2- and 6-weeks of age, and the survival rates between implantation and 2-weeks of age for two diet treatments. We found the mean number of implantation sites and pups whelped during a reproductive cycle was influenced by food-intake prior to conception. Additionally, we found evidence suggesting the effects of nutritional stress may persist for additional breeding cycles. We also provided evidence suggesting well-fed females tended to have more male pups. Understanding how environmental factors influence reproductive output may improve model predictions of coyote population dynamics.

Infectious disease and red wolf conservation: assessment of disease occurrence and associated risks

Infectious diseases pose a significant threat to global biodiversity and may contribute to extinction. As such, establishing baseline disease prevalence in vulnerable species where disease could affect persistence is important to conservation. We assessed potential disease threats to endangered red wolves (Canis rufus) by evaluating regional (southeastern United States) disease occurrences in mammals and parasite prevalence in red wolves and sympatric coyotes (Canis latrans) in North Carolina. Common viral pathogens in the southeast region, such as canine distemper and canine parvovirus, and numerous widespread endoparasites could pose a threat to the red wolf population. The most prevalent parasites in red wolves and sympatric coyotes were heartworm (Dirofilaria immitis), hookworm (Ancylostoma caninum), and Ehrlichia spp.; several red wolves and coyotes were also positive for bacteria causing Lyme disease (Borrelia burgdorferi). Coyotes had a more species-rich parasite community than red wolves, suggesting they could harbor more parasites and act as a disease reservoir. Species identity and sex did not significantly affect parasite loads, but young canids were less likely to have heartworm and more likely to have high levels of endoparasites. Continued disease monitoring is important for red wolf recovery because low levels of genetic variability may compromise the wolves' abilities to combat novel pathogens from closely related species, such as domestic dogs and coyotes.

PARASITOLOGY AND SEROLOGY OF FREE-RANGING COYOTES (CANIS LATRANS) IN NORTH CAROLINA, USA

Coyotes (Canis latrans) have expanded recently into the eastern US and can serve as a source of pathogens to domestic dogs (Canis lupus familiaris), livestock, and humans. We examined free-ranging coyotes from central North Carolina, US, for selected parasites and prevalence of antibodies against viral and bacterial agents. We detected ticks on most (81%) coyotes, with Amblyomma americanum detected on 83% of those with ticks. Fifteen (47%) coyotes were positive for heartworms (Dirofilaria immitis), with a greater detection rate in adults (75%) than juveniles (22%). Serology revealed antibodies against canine adenovirus (71%), canine coronavirus (32%), canine distemper virus (17%), canine parvovirus (96%), and Leptospira spp. (7%). We did not detect antibodies against Brucella abortus/suis or Brucella canis. Our results showed that coyotes harbor many common pathogens that present health risks to humans and domestic animals and suggest that continued monitoring of the coyote's role in pathogen transmission is warranted.

Evaluating noninvasive genetic sampling techniques to estimate large carnivore abundance

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

Balancing sample accumulation and DNA degradation rates to optimize noninvasive genetic sampling of sympatric carnivores

Noninvasive genetic sampling, or noninvasive DNA sampling (NDS), can be an effective monitoring approach for elusive, wide-ranging species at low densities. However, few studies have attempted to maximize sampling efficiency. We present a model for combining sample accumulation and DNA degradation to identify the most efficient (i.e. minimal cost per successful sample) NDS temporal design for capture-recapture analyses. We use scat accumulation and faecal DNA degradation rates for two sympatric carnivores, kit fox (Vulpes macrotis) and coyote (Canis latrans) across two seasons (summer and winter) in Utah, USA, to demonstrate implementation of this approach. We estimated scat accumulation rates by clearing and surveying transects for scats. We evaluated mitochondrial (mtDNA) and nuclear (nDNA) DNA amplification success for faecal DNA samples under natural field conditions for 20 fresh scats/species/season from <1-112 days. Mean accumulation rates were nearly three times greater for coyotes (0.076 scats/km/day) than foxes (0.029 scats/km/day) across seasons. Across species and seasons, mtDNA amplification success was ≥95% through day 21. Fox nDNA amplification success was ≥70% through day 21 across seasons. Coyote nDNA success was ≥70% through day 21 in winter, but declined to <50% by day 7 in summer. We identified a common temporal sampling frame of approximately 14 days that allowed species to be monitored simultaneously, further reducing time, survey effort and costs. Our results suggest that when conducting repeated surveys for capture-recapture analyses, overall cost-efficiency for NDS may be improved with a temporal design that balances field and laboratory costs along with deposition and degradation rates.

Red Wolf (Canis rufus) Recovery: A Review with Suggestions for Future Research

By the 1970s, government-supported eradication campaigns reduced red wolves to a remnant population of less than 100 individuals on the southern border of Texas and Louisiana. Restoration efforts in the region were deemed unpromising because of predator-control programs and hybridization with coyotes. The U.S. Fish and Wildlife Service (USFWS) removed the last remaining red wolves from the wild and placed them in a captive-breeding program. In 1980, the USFWS declared red wolves extinct in the wild. During 1987, the USFWS, through the Red Wolf Recovery Program, reintroduced red wolves into northeastern North Carolina. Although restoration efforts have established a population of approximately 70-80 red wolves in the wild, issues of hybridization with coyotes, inbreeding, and human-caused mortality continue to hamper red wolf recovery. We explore these three challenges and, within each challenge, we illustrate how research can be used to resolve problems associated with red wolf-coyote interactions, effects of inbreeding, and demographic responses to human-caused mortality. We hope this illustrates the utility of research to advance restoration of red wolves.

Attitudes of College Undergraduates Towards Coyotes (Canis latrans) in an Urban Landscape: Management and Public Outreach Implications

Understanding and assessing the public's attitudes towards urban wildlife is an important step towards creating management plans, increasing knowledge and awareness, and fostering coexistence between people and wildlife. We conducted a survey of undergraduate college students in the Washington, D.C. metropolitan area-where coyotes are recent arrivals-to determine existing attitudes towards coyotes and coyote management methods. Amongst other findings, we found that the more a person feared coyotes, the less likely they were to support their presence (p < 0.001), and the less likely they were to believe that pet owners should be directly responsible for protecting their pets (p < 0.001). Respondents demonstrated major gaps in their understanding of basic coyote biology and ecology. Respondents broke wildlife management practices into two categories: those that involved an action on coyotes (both lethal or non-lethal; referred to as "Coyote"), and those that restricted human behavior (referred to as "Human"); the "Human" methods were preferred. We found important differences between key demographic groups in terms of attitudes and management preferences. Our study suggests that wildlife professionals have unique opportunities in urban areas to prevent and reduce conflict before it escalates, in part by targeting tailored outreach messages to various demographic and social groups.

Reproductive Biology of the Coyote (Canis latrans): Integration of Mating Behavior, Reproductive Hormones, and Vaginal Cytology

The reproductive biology of wild Canis species is often described as unique among mammals because an unusual combination of behavioral and physiological characteristics including a seasonally monestrous cycle, copulatory lock or tie, obligatory pseudopregnancy, social monogamy, and biparental care of the young. We investigated social behavior, endocrine profiles, and vaginal cytology of female coyotes (Canis latrans) during 4 breeding seasons, 2000-2003. Blood levels of estradiol, progesterone, prolactin, and relaxin were measured, and mating behavior and changes in vaginal epithelium were documented. After aligning the data from each individual to her estimated day of ovulation, we compared pregnant coyotes with nonpregnant females and evaluated temporal relationships among hormone levels, behavior, and vaginal cytology. We found that patterns of proceptive and receptive behaviors correlated with the secretion of steroid hormones, as did vaginal epithelial cytomorphosis. In addition, although progesterone levels of pregnant and pseudopregnant coyotes were indistinguishable, prolactin demonstrated a discernible intergroup difference and relaxin was only detectable in pregnant females. Although this study included characteristics not previously published for this species, it also showed how key aspects of reproduction were correlated temporally, and emphasized the importance of an integrated perspective when addressing the reproductive biology of coyotes, or other wild species of canids.