Coyote Population Research Articles

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.

High genomic diversity and candidate genes under selection associated with range expansion in eastern coyote (Canis latrans) populations.

Range expansion is a widespread biological process, with well‐described theoretical expectations associated with the colonization of novel ranges. However, comparatively few empirical studies address the genomic outcomes accompanying the genome‐wide consequences associated with the range expansion process, particularly in recent or ongoing expansions. Here, we assess two recent and distinct eastward expansion fronts of a highly mobile carnivore, the coyote (Canis latrans), to investigate patterns of genomic diversity and identify variants that may have been under selection during range expansion. Using a restriction‐associated DNA sequencing (RADseq), we genotyped 394 coyotes at 22,935 SNPs and found that overall population structure corresponded to their 19th century historical range and two distinct populations that expanded during the 20th century. Counter to theoretical expectations for populations to bottleneck during range expansions, we observed minimal evidence for decreased genomic diversity across coyotes sampled along either expansion front, which is likely due to hybridization with other Canis species. Furthermore, we identified 12 SNPs, located either within genes or putative regulatory regions, that were consistently associated with range expansion. Of these 12 genes, three (CACNA1C, ALK, and EPHA6) have putative functions related to dispersal, including habituation to novel environments and spatial learning, consistent with the expectations for traits under selection during range expansion. Although coyote colonization of eastern North America is well‐publicized, this study provides novel insights by identifying genes associated with dispersal capabilities in coyotes on the two eastern expansion fronts.

Coyote (Canis latrans) use of marine resources in coastal California: A new behavior relative to their recent ancestors

Coyotes ( Canis latrans) are known to consume marine foods, but the importance and persistence of marine subsidies to coyotes is unknown. Recent access to a marine subsidy, especially if gained following apex predator loss, may facilitate coyote expansion along coastal routes and amplify the effects of mesopredator release. Our goal was to quantify and contextualize past and present marine resource use by coyotes on the central coast of California via stable isotope analysis. We measured δ13C and δ15N values in coyotes, their competitors, and their food resources at two modern sites, seven archaeological sites spanning in age from ~3000 to 750 BP, and from historical (AD 1893–1992) coyote and grizzly bear hair and bone sourced from coastal counties. We found evidence for marine resource use by modern coastal California coyotes at one site, Año Nuevo, which hosts a mainland northern elephant seal ( Mirounga angustirostris) breeding colony. Seals and sea lions account for ~20% of Año Nuevo coyote diet throughout the year and this marine subsidy likely positively impacts coyote population size. Isotopic data suggest that neither historic nor prehistoric coyotes consumed marine-derived foods, even at sites near ancient mainland seal rookeries. Marine resource use by some contemporary California coyotes is a novel behavior relative to their recent ancestors. We hypothesize that human alteration of the environment through extirpation of the California grizzly bear and the more recent protection of marine mammals likely enabled this behavioral shift.

Response of two sympatric carnivores to human disturbances of their habitat: the bobcat and coyote

Information about human land uses, producing the least impact on wildlife and their habitats, is crucial to develop management strategies allowing coexistence between human beings and wildlife. We investigated the responses of the bobcat (Lynx rufus) and the coyote (Canis latrans) to different types of human activity by assessing the abundance, habitat use, and activity patterns of these species in response to extraction of firewood, grazing, and crop farming within their habitat. Photographic records of both carnivores were obtained from 18 camera-trap stations, distributed evenly within these three types of habitat disturbances. The highest relative abundance index for both carnivores was obtained at firewood extraction sites, followed by grazing sites, and croplands. The probability of carnivore sightings varied between species by type of disturbance and by season. The probability of bobcat sightings was highest within firewood extraction sites, with no effect of season, whereas that of the coyote was highest during winter, with no effect of type of human disturbance. An analysis of habitat use revealed that both carnivores avoided cropland sites. Activity patterns were similar, which suggests an absence of temporal segregation between these species; moreover, the activity patterns of both carnivores seems to be affected by intensity of human activities. Preference for woodland habitats by both carnivores denotes that firewood extraction is the disturbance that least affects bobcat and coyote populations; therefore, this kind of human activity could be the least impacting type of disturbance for the coexistence between humans and these carnivore species.

It takes two: Evidence for reduced sexual conflict over parental care in a biparental canid

In biparental systems, sexual conflict over parental investment predicts that the parent providing care experiences greater reproductive costs. This inequality in parental contribution is reduced when offspring survival is dependent on biparental care. However, this idea has received little empirical attention. Here, we determined whether mothers and fathers differed in their contribution to care in a captive population of coyotes (Canis latrans). We performed parental care assays on 8 (n = 8 males, 8 females) mated pairs repeatedly over a 10-week period (i.e., 5–15 weeks of litter age) when pairs were first-time breeders (2011), and again as experienced breeders (2013). We quantified consistent individual variation (i.e., repeatability) in 8 care behaviors and examined within- and among-individual correlations to determine if behavioral plasticity within or parental personality across seasons varied by sex. Finally, we extracted hormone metabolites (i.e., cortisol and testosterone) from fecal samples collected during gestation to describe potential links between hormonal mechanisms and individual consistency in parental behaviors. Parents differed in which behaviors were repeatable: mothers demonstrated consistency in provisioning and pup-directed aggression, whereas fathers were consistent in pup checks. However, positive within-individual correlations for identical behaviors (e.g., maternal versus paternal play) suggested that the rate of change in all behaviors except provisioning was highly correlated between the sexes. Moreover, positive among-individual correlations among 50% of identical behaviors suggested that personality differences across parents were highly correlated. Lastly, negative among-individual correlations among pup-directed aggression, provisioning, and gestational testosterone in both sexes demonstrated potential links between preparental hormones and labile parental traits. We provide novel evidence that paternal contribution in a biparental species reaches near equivalent rates of their partners.

Demographic history influences spatial patterns of genetic diversityin recently expanded coyote (Canis latrans) populations.

Human-mediated range expansions have increased in recent decades and represent unique opportunities to evaluate genetic outcomes of establishing peripheral populations across broad expansion fronts. Over the past century, coyotes (Canis latrans) have undergone a pervasive range expansion and now inhabit every state in the continental United States. Coyote expansion into eastern North America was facilitated by anthropogenic landscape changes and followed two broad expansion fronts. The northern expansion extended through the Great Lakes region and southern Canada, where hybridization with remnant wolf populations was common. The southern and more recent expansion front occurred approximately 40 years later and across territory where gray wolves have been historically absent and remnant red wolves were extirpated in the 1970s. We conducted a genetic survey at 10 microsatellite loci of 482 coyotes originating from 11 eastern U.S. states to address how divergent demographic histories influence geographic patterns of genetic diversity. We found that population structure corresponded to a north-south divide, which is consistent with the two known expansion routes. Additionally, we observed extremely high genetic diversity, which is atypical of recently expanded populations and is likely the result of multiple complex demographic processes, in addition to hybridization with other Canis species. Finally, we considered the transition of allele frequencies across geographic space and suggest the mid-Atlantic states of North Carolina and Virginia as an emerging contact zone between these two distinct coyote expansion fronts.

Introduction of canine parvovirus 2 into wildlife on the Island of Newfoundland, Canada

Canine parvovirus-2 (CPV-2) and feline panleukopenia virus (FPV) (species Carnivore protoparvovirus 1, family Parvoviridae) cause a severe gastrointestinal disease associated with immune depression in a broad range of terrestrial carnivores. We report here the first molecular epidemiological investigation of protoparvoviruses on the Island of Newfoundland, Canada. In particular, we investigated red foxes (Vulpes vulpes deletrix) and lynx (Lynx canadensis subsolanus), two autochthonous species, and coyotes (Canis latrans), which immigrated onto the island during the 1980s. CPV-2 was identified in coyotes (3/85, 3.5%), while no viruses were found in lynx (0/38) or foxes (0/22). Based on complete genome analyses, two of the identified viruses (which were 99.98% identical to each other) were variant CPV-2b, while the third strain was a CPV-2a variant. Phylogenetic analyses showed that the CPV-2b viruses were part of a group that also included viruses identified in wildlife in the USA (including coyotes) while the CPV-2a virus clustered with viruses identified in dogs. We conclude that the CPV-2b viruses could have been introduced into Newfoundland during the immigration of coyotes, while the CPV-2a virus was possibly introduced into the coyote population from an infected dog. Although a more extended screening effort is required, our preliminary data suggest that FPV is not circulating in Newfoundland and that CPV-2 viruses have not spread from coyotes to the other investigated autochthonous wild carnivores.

Reproductive characteristics of a coyote population before and during exploitation

ABSTRACTThe eastward expansion of coyotes (Canis latrans) has brought the species into ecosystems and landscapes different from those it historically occupied, yet little is known about the reproductive biology of coyotes in the southeastern United States or the effects of exploitation on reproduction in coyotes. Our objective was to quantify litter size, pregnancy rate, and fecundity in an essentially unexploited coyote population in South Carolina, USA and to evaluate the effect of exploitation on these parameters. We examined reproductive tracts from 235 female coyotes trapped during 2010–2012. Placental scars from coyotes trapped during 2010 indicated that prior to trapping (2009), pregnancy rates were zero for juveniles, 0.25 for yearlings, and 0.389 for adults. Litter size for adults during 2009 averaged 5.4 pups/female, resulting in fecundity of 2.1 pups/female. The number of coyotes trapped was similar among years, indicating that the population recovered following trapping each year, but it shifted toward a younger age structure during trapping. However, although pregnancy rate, litter size, and fecundity of adults all tended to increase from pre‐trapping (2009) through the last trapping period (2011–2012), differences were not significant for this or any other age class. Fecundity of the population did not significantly increase during the first year of trapping (2010) but was lower during the last trapping period (2011–2012; 0.56 ± 0.15 [95% CL]) than prior to trapping (0.90 ± 0.15 [95% CL]). Thus, we observed only weak evidence for compensatory reproduction in response to trapping pressure and conclude that the increase in the juvenile component of the population was attributable primarily to immigration from neighboring areas rather thanin situreproduction. This increased representation of juveniles in the population, which rarely bred, coupled with a concurrent decrease in adults, which accounted for 59.2% of breeding, explains the reduction in population fecundity. High immigration rates as indicated herein render coyote populations extremely difficult to control. © 2017 The Wildlife Society.

Effect of compensatory immigration on the genetic structure of coyotes

ABSTRACTDespite efforts to reduce their effects on livestock and native ungulates within the southeastern United States, coyotes (Canis latrans) can recover from control programs. It is unknown how coyotes compensate for high mortality following trapping, so there is great interest to identify methods that can provide insight into coyote response to intensive trapping. To investigate if population genetic tools can decipher how coyotes recover from intensive trapping, we combined an empirical test of how genetic differentiation, diversity, and familial structure changed following trapping on the Savannah River Site (SRS), South Carolina, USA, with spatially explicit genetic simulations. The pre‐ and post‐trapping periods had similar genetic diversities and were not genetically differentiated as expected by either compensatory reproduction or immigration from a single genetic source. The post‐trapping coyote populations exhibited weaker signatures of philopatry with little evidence for increased dispersal distances of young coyotes, which suggests immigration caused a decrease in familial structure. Our simulations indicated that spatial autocorrelation coefficients and observed heterozygosities change as immigration increases, whereas population differentiation, allelic richness, and displacement distances do not. Collectively, our results suggest that coyotes recover from intensive trapping via reproduction and immigration, which likely makes preventing compensation difficult. Monitoring post‐trapping populations may offer more insight into maximizing the effectiveness of control efforts, and based on our simulations, population genetics can provide critical information about the amount of compensatory immigration following trapping. © 2017 The Wildlife Society.

Stable Isotope Analysis of Dietary Overlap between the Endangered Red Wolf and Sympatric Coyote in Northeastern North Carolina

The only remaining wild Canis rufus (Red Wolf) are part of an experimental population inhabiting the Albemarle peninsula of northeastern North Carolina. This population was established in the late 1980s as part of the US Fish and Wildlife Service's Red Wolf Recovery Program. Recently, controversy has arisen over whether to maintain, expand, or end the recovery program. This controversy is complex, but one source of concern about the program is the perception among some local stakeholders that, compared to the smaller, sympatric C. latrans (Coyote), Red Wolves put greater pressure on game species, such as Odocoileus virginianus (White-tailed Deer). However, previous research comparing fecal remains indicated a broad dietary overlap between sympatric populations of the 2 species. In this study, we investigated the question of dietary overlap between Red Wolves and Coyotes using stable isotope analysis. Our results are consistent with those based on fecal analyses in showing that sympatric populations of Red Wolves and Coyotes have similar diets. This finding has important conservation and management implications for Red Wolves because it suggests that: (1) this species does not prey upon game species, such as White-tailed Deer, to any greater degree than sympatric Coyotes; and (2) whereas the loss of the only wild population of Red Wolves would result in a reduction of phylogenetic diversity in northeastern North Carolina, it may not result in a loss of functional diversity if Coyotes or Coyote—Red Wolf hybrids are able to play a similar ecological role to that of Red Wolves.

Effects of removal on a lightly exploited coyote population in eastern Nevada

Coyote (Canis latrans) removal is a common, yet controversial, management practice to increase game populations throughout the West. I studied the effect of removal on coyote populations in eastern Nevada from 2004 to 2008 and reviewed 27 available publications to determine the level of human exploitation on my study populations. Removals were performed by USDA Wildlife Services (WS) to benefit game populations and involved the use of trapping, neck snaring, and ground and aerial shooting. To determine if the removal had an effect on the coyote populations, I measured 3 parameters: the presence or absence of skewed sex ratios; proportions of juveniles in the population; and average adult age. Sex was determined at the time of ground removal efforts. Canine teeth were acquired from 96% of coyotes removed from the ground; cementum annuli analysis was performed for aging. Due to WS removal efforts prior to 2004, coyote populations likely were in a lightly exploited state when the study began. Where removal efforts were the highest (65% of total), there was a resulting decline in the mean age of coyotes, an increase in percentage of juveniles in the population, and a skewed sex ratio, indicating that this population may be heavily exploited. No change in these parameters occurred in areas where 35% of the total removals occurred. This information should help wildlife managers understand the exploitation levels of their own coyote populations.

The dynamic nature of territoriality, transience and biding in an exploited coyote population

Ideal despotic distribution theory and resource dispersion theory predict that individuals in populations of territorial species arrange themselves in space according to dominance and resource dispersion. When available territories are saturated, this can result in competition for preferred territories. Recently, transience in coyote populations was suggested as an advantageous life history strategy, even though transients may incur higher mortality and do not typically contribute reproductively to the population at that time. Here we assess potential types of biding, or awaiting better territory opportunities, in a highly‐exploited coyote population in Virginia, USA. We used relocation data from coyotes collared from July 2011 — March 2014 to classify residents and transients based on a 95% home range area over a three‐month moving window. We estimated home range stability as the distance between successive activity centers and compared it between subadults and adults. We used home range stability relative to home range area to identify extra‐territorial excursions and territory turnover, or resident shifts into adjacent territories. Some coyotes adhered to the traditional form of transience, occupying very large home ranges or biding areas overlapping several resident territories, until a territory became vacant. Conversely, other individuals displayed evidence of resident territory turnover, suggesting individuals may use low quality territories as biding areas, waiting for better quality territories to become vacant. We suggest this biding population provides the capacity for rapid compensatory immigration. In response to high levels of mortality in exploited coyote populations, removal of individuals from territories may result in immediate colonization by another individual, confounding efforts to reduce overall coyote density. Thus, transience and biding may regulate population density and be a potentially advantageous life history strategy and may have implications for management of saturated populations of social predators.

Gastrointestinal helminths of Coyotes (Canis latrans) from Southeast Nebraska and Shenandoah area of Iowa.

Aim:This survey was carried out on the carcasses of 29 coyotes from Southeastern Nebraska and Shenandoah area of Iowa to document the helminths present in the intestinal track of these carnivorous animals.Materials and Methods:A total of 29 adult coyote carcasses were generously donated in the autumn and winter (November-February) of 2014-2015 by trappers, fur buyers and hunters of Southeast Nebraska and Shenandoah area of Iowa. The intestine of individual animals were examined for the recovery of helminth parasites as per the established procedures.Results:We found that as many as 93.10% of the investigated coyotes were infected with one or more helminth infections. A total of 10 different species of helminth parasites were recovered from the intestines of coyotes under investigation. Among the 10 species of helminths, 5 were identified as cestodes while the remaining 5 were nematodes. A total of 82.75% of the animals were infected with one or more species of nematodes, while 75.86% of them were colonized with one or more species of cestode parasites. The most abundant species in coyotes were Toxascaris leonina (68.95%) closely followed by Taenia hydatigena (58.62%). The prevalence of Ancylostoma caninum and Taenia pisiformis were recorded at 31.03%, followed by those of Toxocara canis and Echinococcus spp. at 24.13%, respectively. Three animals were infected with Trichuris vulpis while three other coyotes each were found to be harboring Uncinaria stenocephala, Dipylidium caninum, or Hymenolepis diminuta. The presence of H. diminuta might have been the result of the ingestion of a rodent by the respective coyotes.Conclusion:From the overall analysis of the present data and comparing it with the previous reports of various scientists over several decades, we can conclude that intestinal helminths are still very much prevalent among the coyote population in the Southeast Nebraska and Iowa area. The relatively high prevalence of the zoonotic parasite species further warrants a more comprehensive investigation with larger numbers of wild predators from the region to ascertain the possible contribution of coyotes to the disease cycle as these animals are more frequently spotted in and around the densely populated urban areas.

Polymorphisms in ERAP1 and ERAP2 are shared by Caninae and segregate within and between random- and pure-breeds of dogs

Specific polymorphisms in the endoplasmic reticulum amino peptidase genes ERAP1 and ERAP2, when present with certain MHC class receptor types, have been associated with increased risk for specific cancers, infectious diseases and autoimmune disorders in humans. This increased risk has been linked to distinct polymorphisms in both ERAPs and MHC class I receptors that affect the way cell-generated peptides are screened for antigenicity. The incidence of cancer, infectious disease and autoimmune disorders differ greatly among pure breeds of dogs as it does in humans and it is possible that this heightened susceptibility is also due to specific polymorphisms in ERAP1 and ERAP2. In order to determine if such polymorphisms exist, the ERAP1 and ERAP2 genes of 10 dogs of nine diverse breeds were sequenced and SNPs causing synonymous or non-synonymous amino acid changes, deletions or insertions were identified. Eight ERAP1 and 10 ERAP2 SNPs were used to create a Sequenom MassARRAY iPLEX based test panel which defined 24 ERAP1, 36 ERAP2 and 128 ERAP1/2 haplotypes. The prevalence of these haplotypes was then measured among dog, wolf, coyote, jackal and red fox populations. Some haplotypes were species specific, while others were shared across species, especially between dog, wolf, coyote and jackal. The prevalence of these haplotypes was then compared among various canid populations, and in particular between various populations of random- and pure-bred dogs. Human-directed positive selection has led to loss of ERAP diversity and segregation of certain haplotypes among various dog breeds. A phylogenetic tree generated from 45 of the most common ERAP1/2 haplotypes demonstrated three distinct clades, all of which were rooted with haplotypes either shared among species or specific to contemporary dogs, coyote and wolf.

Admixture mapping identifies introgressed genomic regions in North American canids.

Hybrid zones typically contain novel gene combinations that can be tested by natural selection in a unique genetic context. Parental haplotypes that increase fitness can introgress beyond the hybrid zone, into the range of parental species. We used the Affymetrix canine SNP genotyping array to identify genomic regions tagged by multiple ancestry informative markers that are more frequent in an admixed population than expected. We surveyed a hybrid zone formed in the last 100years as coyotes expanded their range into eastern North America. Concomitant with expansion, coyotes hybridized with wolves and some populations became more wolflike, such that coyotes in the northeast have the largest body size of any coyote population. Using a set of 3102 ancestry informative markers, we identified 60 differentially introgressed regions in 44 canines across this admixture zone. These regions are characterized by an excess of exogenous ancestry and, in northeastern coyotes, are enriched for genes affecting body size and skeletal proportions. Further, introgressed wolf-derived alleles have penetrated into Southern US coyote populations. Because no wolves currently exist in this area, these alleles are unlikely to have originated from recent hybridization. Instead, they probably originated from intraspecific gene flow or ancient admixture. We show that grey wolf and coyote admixture has far-reaching effects and, in addition to phenotypically transforming admixed populations, allows for the differential movement of alleles from different parental species to be tested in new genomic backgrounds.

Monitoring coyote population dynamics with fecal DNA and spatial capture-recapture

Estimating coyote (Canis latrans) density and other demographic parameters is difficult, particularly for populations that exist at low density. This is the situation for recently established coyote populations in the eastern United States where populations may be below carrying capacity and growth unregulated. We used non-invasive fecal DNA collected from 5 scat sampling sessions over 2.5 years to estimate population parameters (i.e., density, apparent survival, recruitment, and population growth) for coyotes at 2 different sites in the Ridge and Valley region of the central Appalachians in Virginia, USA. We identified individuals using microsatellite genotypes and estimated apparent survival for the local population at both sites across the 5 sessions in a single Cormack–Jolly–Seber model. We estimated density for each site and session separately using single session spatial replicates of 0.5-km transect segments as traps in a spatial capture–recapture model. Finally, we derived estimates of recruitment and population growth using an ad hoc robust design approach. We were able to estimate population parameters, even though coyote densities at both sites were low. Generally, derived recruitment and apparent survival were inversely related across sites, however, precision in estimates was poor. Thus, although there appeared to be some differences in demographic estimates for local coyote populations, uncertainty in parameters was too great to detect changes in demographic rates over short periods of time using ad hoc robust design. However, the non-invasive genetic sampling and spatial capture–recapture approach provides a useful methodology and framework for future research intended to estimate population dynamics for coyotes. This method will also be useful for other species that occur at low densities, over large spatial scales, and lack distinguishing marks for camera-trap surveys. Finally, we believe this method will allow for detection of population trends over greater periods of time, and we consider alternate sampling strategies and modeling approaches that may improve the ability to estimate demographic rates of change for coyote populations using noninvasive genetics and spatial capture–recapture. © 2016 The Wildlife Society.

Spatial response of coyotes to removal of water availability at anthropogenic water sites

Features containing year-round availability of free water (hereafter water sites) and areas affiliated with water sites (i.e., riparian zones) occurring within arid landscapes represent a potential limiting resource for some desert dwelling vertebrates. Little is known about the relationship between water sites and mammalian carnivores. An increase of water sites in portions of the Great Basin Desert in Utah reportedly contributed to an increase in coyote (Canis latrans) abundance. We examined frequency of visitation and spatial affinity of resident coyotes for water sites at the home range scale extent. Visitation to sites with available water averaged 13.0 visitations/season (SD = 13.5) and ranged from zero to 47. We documented no visits to water sites in 16% (10 of 64) of seasonal home-ranges, <5 visits within 39% (25 of 64) of home ranges, and 25% (28 of 113) of coyote home-ranges did not contain a water site. Water sites associated with riparian vegetation experienced higher visitation than guzzlers (no riparian vegetation present). We found no evidence that removal of water influenced home range size or spatial shifting of home range areas. Water sites, especially guzzlers, do not represent a pivotal resource for the coyote population in our study area.

Natality of Yearling Coyotes in West Virginia

Abstract Minimal information is available regarding the reproduction of coyotes (Canis latrans) in the Mid-Atlantic region, which includes the states of Delaware, Maryland, North Carolina, Pennsylvania, Virginia, and West Virginia. Since reproductive information is useful to assess populations and determine management strategies and because this information is unavailable for the Mid-Atlantic, we examined uterine tracts of 66 female coyotes collected from February to May 2010 for fetuses. We measured fetuses using a digital caliper and approximated dates of conception and parturition. Nine (13.6%) female coyotes were pregnant with visible fetuses; seven of these females were yearlings (1.5–2.5 y old). Average litter size of yearling coyotes was 5.4 (SE = 0.48). We estimated an average conception date of 2 February and an average parturition date of 6 April. Conception and parturition dates were within the reported range for coyotes, though one female successfully bred in early January, which is earlier than reported in the literature. The relatively high proportion (30.4%) of yearling females breeding in West Virginia may reflect abundant food resources, low density of coyotes, increasing human-caused mortality, or a combination of these factors. Reproductive information reported here will be helpful in monitoring coyote population trends and in the assessment of management strategies.

Food Habits and Anthropogenic Supplementation in the Diet of Coyotes (Canis latrans) along an Urban-Rural Gradient

Coyotes are recent colonists of the Southeast and have broadened their niche to include exploitation of urban areas. The aim of this study was to examine diet of coyotes inhabiting areas of differential development by humans and assess prevalence of anthropogenic feeding, to detect a possible shift in dietary trends. In urban, exurban, and rural areas of east-central Alabama, 159 fecal samples were collected and examined to reconstruct the diet. Consumption of anthropogenic food did not vary significantly along an urban-rural gradient and foods consumed were similar among habitats. While results of this study can provide insight to guide decisions about managing populations of urban-exurban coyotes in the Southeast, further research should be conducted in a diversity of developed areas to assist wildlife managers in evaluating strategies for managing populations of urban-exurban coyotes.

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.