Coyote Scats Research Articles

Taphonomic comparison of bones in mountain lion scats, coyote scats, golden eagle pellets, and great-horned owl pellets

Bones consumed by carnivores and raptors, and subsequently deposited on the landscape in scats and pellets, respectively, can make up a considerable portion of the faunal remains recovered by North American archaeologists, particularly in caves and rockshelters. This paper compares and contrasts bones recovered from the scats of the mountain lion and coyote, as well as from the pellets of the great-horned owl and golden eagle. Bones in lion scats, coyote scats, and eagle pellets all may be relatively large in size, and display considerable etching, corrosion, and polishing, although bones in coyote scats tend to be smaller in size compared to those in lion scats. Bones in great-horned owl pellets tend to be larger in size and show much less degree of corrosion and polishing compared to the scats and eagle pellet bones.

Coyote diets in a longleaf pine ecosystem

The ecological implications of coyote Canis latrans colonization of the eastern USA have drawn considerable interest from land managers and the general public. The ability to predict how these ecosystems, which have lacked larger predators for decades, would respond to the invasion of this highly adaptable species needs an understanding of coyote foraging behavior given local resource availability. Therefore, we examined the diet of coyotes in a longleaf pine Pinus palustrus ecosystem from 2007–2012. We examined 673 coyote scats collected on the Joseph W. Jones Ecological Research Center in southwestern Georgia. We observed considerable seasonality in coyote use of rodents, white‐tailed deer Odocoileus virginianus, rabbits and vegetation. Coyotes exploited anthropogenic food sources, particularly waste peanuts Arachis hypogaea, during the fall and winter when native soft mast was not available. Adult white‐tailed deer were consumed during every month and was not limited to the pulse of carrion availability from hunter‐harvested animals, suggesting the use of adult white‐tailed deer may not be restricted to scavenging in this system. We found mesomammals, including armadillos Dasypus novemcinctus, raccoons Procyon lotor, Virginia opossums Didelphis viginiana, bobcats Lynx rufus, grey foxes Urocyon cineroargenteus and striped skunks Mephitis mephitis in approximately 18% of coyote scats from January–August. On our site, and some adjacent properties, the use of predator trapping focused primarily on Virginia opossum, raccoon, coyote, bobcat and gray fox, to increase northern bobwhite Colinus virginianus production may have resulted in increased use of mesomammals through scavenging. We offer evidence that coyote colonization may alter food web dynamics in longleaf pine ecosystems through depredation of white‐tailed deer and by influencing the mesomammal guild through direct predation and competition for rodents, rabbits, carrion and soft mast.

Quantifying and correcting for scat removal in noninvasive carnivore scat surveys

Scat surveys are commonly used to monitor wildlife populations. For carnivores, surveys are typically conducted along roads and trails. Scats available for detection may not reflect scats deposited and variation in disappearance may bias results. Previous research has investigated natural decay and deterioration, but scats deposited along roads or trails are likely influenced to a greater degree by anthropogenic disturbance in some systems. We used experimental plots to evaluate variation in scat removal for two model carnivores, coyote Canis latrans and kit fox Vulpes macrotis, along roads in the Great Basin Desert, USA. Using parametric survival regression, we predicted scat survival and developed persistence‐rate correction factors, which were applied to results from relative abundance scat surveys conducted along 15 transects. Kit fox scats disappeared more rapidly than coyote scats, with 3.3% and 10.6%, respectively, persisting through 42 days. At 14 days, 90.8‐41.7% of scats had been removed across road types. Survival models indicated species, road type, scat position and daily traffic were important predictors of scat persistence. Applying persistence‐rate correction factors to scat survey results altered the inferred relative abundances. Across seasons, mean corrected:uncorrected relative abundance ratios ranged from 1.0–91.2 for coyotes and 1.3–139.3 for kit foxes, with higher mean ratios being influenced by high corrected relative abundances on roads with high traffic volumes. Understanding scat removal rates and patterns can improve inferences from surveys. Persistence‐rate correction factors can be used to reduce bias in indices of abundance, but caution should be used when removal rates are high. Knowledge of spatial variation in persistence can elucidate concerns of false‐positives and false‐negatives in occupancy and capture—recapture studies. Considering the disparity in scat removal between species and among road types and positions, we recommend practitioners quantify and consider variation in removal when interpreting scat survey results.

Food Habits of Coyotes, Gray Foxes, and Bobcats in a Coastal Southern California Urban Landscape

Abstract. Many carnivores are sensitive to habitat fragmentation, and the capacity to shift diets may improve their ability to persist in urban areas. We collected and identified contents of a total of 119 scats from coyotes (Canis latrans), 58 scats from gray foxes (Urocyon cinereoargenteus), and 31 scats from bobcats (Lynx rufus) within habitat fragments of varying size in the San Diego area in coastal southern California. Coyote diet was generalist, composed of mostly mammals but also anthropogenic items, fruit and seeds, birds, and invertebrates. Dietary breadth of coyotes was similar in small urban habitat fragments and larger sites, but composition differed, suggestive of the opportunistic habits of coyotes. Notably, domestic cats occurred in 29% of coyote scats in small urban fragments, implicating coyotes as a threat to cats. Like coyotes, gray foxes had an omnivorous diet consisting of mammals, fruit and seeds, invertebrates, and birds. As with coyotes, dietary breadth of gray foxes was similar i...

Seasonal Coyote Diet Composition at a Low-Productivity Site

Abstract Canis latrans (Coyote) recently expanded its range into the southeastern US, where local data on Coyote diets are lacking. We studied Coyote diets in a low-productivity area where food resources may be scarce. We determined Coyote diet composition through analysis of 315 scats collected at Fort Bragg Military Installation, Fort Bragg, NC, between May 2011 and July 2012. Odocoileus virginianus (White-tailed Deer) was the most common mammalian food item, occurring in 14.9% of all scats and 42.5% of winter scats. Soft-mast occurrence in Coyote diets was greatest in the fall, when Diospyros virginiana (Persimmon) occurred in most Coyote scats (95.7%). Coyotes on our low-productivity study site shifted their diets throughout the year based on the availability of food items and had a diet diversity similar to what has been reported for animals elsewhere in the species' range.

Local-Scale Difference of Coyote Food Habits on Two South Carolina Islands

Canis latrans (Coyote) is regarded as a classic generalist predator that has recently established large populations throughout the southeastern US. To better understand how Coyote food habits in the Southeast may differ on an extremely small spatial scale, we collected a total of 305 Coyote scats from 2009 to 2011 on 2 islands separated by a 1.4–2.5-km-wide expanse of low saltwater-marsh on the coast of Georgetown, SC. We identified diagnostic remains of prey items to the lowest possible taxonomic level. A multi-response permutation procedure revealed differences in Coyote diet composition between islands (A = 0.0090, P < 0.0001). Subsequent indicator-species analysis revealed a total of 4 food items that served to differentiate diet between islands: birds. Sus scrofa (Wild Hog), Ilex sp. (holly) fruit, and lagomorphs. Our results demonstrate that Coyote food habits and their potential ecosystem effects may vary widely on a very local scale. This finding may be of particular concern to biologists attempting to utilize published diet studies to inform Coyote management strategies. Our study also documented some of the highest levels of bird consumption by Coyotes published to date; we detected bird remains found in 42.45–59.80% of scats.

Scale-Dependent Effects of Coyote-Predation Risk on Patterns of White-Tailed Deer Browsing along Linear Forest Edges

Abstract Browsing by Odocoileus virginianus (White-tailed Deer) plays an important role in shaping forest structure in the northeastern US. Predation can influence patterns of browse through decreasing White-tailed Deer abundance and influencing patterns of habitat selection. Canis latrans (Coyote) is the dominant predator of White-tailed Deer in our focal region in northern New York. Optimal foraging theory suggests that White-tailed Deer browse in locations that maximize energy intake while minimizing predation risk. Linear forest edges provide abundant woody browse for White-tailed Deer, but are also used as travel-ways by Coyotes in our focal region. These locations therefore provide a venue for testing the extent to which predation risk influences patterns of White-tailed Deer browsing. We quantified White-tailed Deer browse use for edge and interior sites and the density of Coyote scats along seventeen 500-m transects to evaluate the scale at which White-tailed Deer herbivory was affected by Coyote ...

Determinación de la dieta estacional del coyote (Canis latrans) en la región norte de la Reserva de la Biosfera Mapimí, México

In this study we determined and compared coyote diet within and out of the Mapimí Biosphere Reserve. We collected 201 coyote scats, 62 in the dry season and 139 in the rainy season from March 2000 to March 2001. Samples were analyzed for the general area and by sites. We identified 50 and 45 items for the dry and rainy season, respectively. Out of 299 items identified for the dry season and 894 for the rainy season, the more frequent items were arthropods, mainly Acrididae, Cicadellidae, Coleoptera and Lepidoptera; mammals, mainly Lepus californicus and Sylvilagus audubonii. Plant material, reptiles and birds were less frequently consumed items. Mammals provided the greatest biomass, 86.5% in the dry season and 72.5% in the rainy season. Plant material was consumed more frequently at less modified sites. These results support the idea that coyote is a generalist, omnivore and opportunist predator, with a strong tendency to consume arthropods during the whole year, although the greatest biomass is obtained from mammals.

Climatic variation and tortoise survival: Has a desert species met its match?

While demographic changes in short-lived species may be observed relatively quickly in response to climate changes, measuring population responses of long-lived species requires long-term studies that are not always available. We analyzed data from a population of threatened Agassiz’s desert tortoises (Gopherus agassizii) at a 2.59km2 study plot in the Sonoran Desert ecosystem of Joshua Tree National Park, California, USA from 1978 to 2012 to examine variation in apparent survival and demography in this long-lived species. Transect-based, mark-recapture surveys were conducted in 10 of those years to locate living and dead tortoises. Previous modeling suggested that this area would become unsuitable as tortoise habitat under a warming and drying climate scenario. Estimated adult population size declined greatly from 1996 to 2012. The population appeared to have high apparent survival from 1978 to 1996 but apparent survival decreased from 1997 to 2002, concurrent with persistent drought. The best model relating apparent survivorship of tortoises ⩾18cm over time was based on a three year moving average of estimated winter precipitation. The postures and positions of a majority of dead tortoises found in 2012 were consistent with death by dehydration and starvation. Some live and many dead tortoises found in 2012 showed signs of predation or scavenging by mammalian carnivores. Coyote (Canis latrans) scats and other evidence from the site confirmed their role as tortoise predators and scavengers. Predation rates may be exacerbated by drought if carnivores switch from preferred mammalian prey to tortoises during dry years. Climate modeling suggests that the region will be subjected to even longer duration droughts in the future and that the plot may become unsuitable for continued tortoise survival. Our results showing wide fluctuations in apparent survival and decreasing tortoise density over time may be early signals of that possible outcome.

Population‐level response of coyotes to a pulsed resource event

AbstractFrom foraging theory, generalist predators should increase consumption of prey if prey availability increases. Pulsed resource events introduce a large influx of prey to predators that may exhibit a functional response of increased consumption rate on, or specialization to, this abundant food resource. We predicted that coyotes (Canis latrans) would respond functionally to numerical increases of neonate white‐tailed deer (Odocoileus virginianus) during the pulsed resource event of parturition. We used howl surveys and deer camera surveys with occupancy modeling to estimate densities for coyotes, adult deer, and fawns, respectively, in Upper Peninsula of Michigan, USA, 2009–2011. We estimated biomass of adult and fawn deer consumed by coyotes during 2 periods [fawn limited mobility period (LMP) and social mobility period (SMP)] in May–August each year. Coyote densities were 0.32 and 0.37/km2 for 2010–2011, respectively. Adult deer densities (3.7–3.9/km2) and fawn densities (0.6–1.3/km2) were similar across years. Overall, fawn hair occurrence in coyote scats was 2.3 times greater in LMP than SMP. Estimated consumption of fawns between periods (n = 157–880) by coyotes varied, suggesting a functional response, with increasing consumption of fawns relative to their availability. Coyotes, on average, consumed 2.2 times greater biomass of fawns than adults across years, and consumed 1.5 times greater fawn biomass, on average, during LMP than SMP. We suggest that consumption rates of coyotes is associated positively with increases in fawn density, and fawn consumption by coyotes follows predictions of optimal foraging theory during this pulsed resource event.

Survival Estimates of White-tailed Deer Fawns at Fort Rucker, Alabama

Decreases in white-tailed deer (Odocoileus virginianus) fawn recruitment have been noted at several locations across the Southeast. Understanding the reason for these decreases is important for management of deer populations. We monitored fawns from birth until 6 mo to examine age and cause specific mortality rates, at Fort Rucker, Alabama. During 2009–2010, 14 fawns were captured immediately after birth and monitored, with three surviving until 6 mo of age. Six of 7 predation events were attributed to coyotes (Canis latrans), and we determined coyote density in the study area during 2010, using DNA isolated from 44 coyote scats, to be 0.40 coyotes/km2. This study, like other recent studies in the Southeast, has found low fawn recruitment seems to be driven by coyote predation.

Survey of the Prevalence and Diversity of Intestinal Parasites Through Scat Analysis of Canids at Letterkenny Army Depot, Franklin County, Pennsylvania

ABSTRACT The increased spread of Echinococcus multilocularis into novel areas has created a need for early detection and monitoring of parasites within wild canid populations. In order to survey the prevalence and relative intensity of helminthes in wild canid populations, coyote, red fox and gray fox scat samples were collected during February and March 2012 at Letterkenny Army Depot, in south central Pennsylvania, USA. Using standard fecal flotation, 13 different parasites were identified in 75 fecal samples, of which 40% of coyote (n=35) and 72.5% (n=40) of fox samples contained evidence of at least one parasite. This represents 8 new species now known to parasitize coyotes and foxes in Letterkenny Army Depot when compared with previous published research. Eleven of the 13 parasites identified were shared between coyotes and foxes. Fox samples had a higher prevalence of parasitism than did coyote samples; however, the relative intensity of parasitism was greater in coyote samples. While parasitism with Taenia sp., Capillaria sp., Isospora sp., Toxocara canis, Toxascaris leonina, Strongyloides stercoralis and Uncinaria stenocephala is likely detrimental, we did not identify Echinococcus sp. or other zoonotic parasites. We recommend continued surveillance for parasites found within wild canids through standard fecal flotation techniques as well as molecular and specific DNA analyses.

Is the Coyote (Canis latrans) a Potential Seed Disperser for the American Persimmon (Diospyros virginiana)?

Abstract The role of carnivores in seed dispersal has only recently been studied in North American plants. We investigated the potential effectiveness of the Coyote (Canis latrans) as a seed disperser for American Persimmon (Diospyros virginiana; Ebenaceae) and tested the effect of experimental design in gut passage experiments. Germination percentage and rate and vigor of seedlings produced by D. virginiana seeds collected from Coyote scat were compared to seeds removed from or contained in whole fruit in a common garden experiment. Germination percentages for Coyote ingested seeds and whole fruit were nearly the same. Emergence was significantly faster for seedlings produced from ingested seeds compared to those seeds in whole fruit, however the quality of these seedlings was significantly poorer. Seedlings produced by seeds artificially removed from fruits had greater survival than those resulting from seeds ingested by coyotes or contained in intact fruits. Our results suggest that Coyotes can effecti...

Propagation methods for Washingtonia filifera: (Linden ex Andre) H. Wendl. (Arecaceae)

California fan palm, also known as desert fan palm ( Washingtonia filifera (Linden ex Andre) H. Wendl. [Arecaceae]) is a ubiquitous species within the highly restricted and unique desert oases ecosystems of the Sonoran, Mojave, and extreme southeastern Colorado desert regions. Today, many of the desert oases are threatened by groundwater removal. Fresh seeds can be sown without treatment, and seeds collected from coyote scat have also germinated well.

Seasonal Variation of Coyote Diet in Northwestern Wyoming: Implications for Dietary Overlap with Canada Lynx?

Exploitative competition through resource utilization may occur between coyotes (Canis latrans) and other carnivores. In the southern periphery of Canada lynx (Lynx canadensis) range, there is concern that increased snowmobile activity may enable coyotes to increase their movements into deep snow areas during the winter months, thereby potentially creating heightened resource competition with lynx, mainly for the lynx’s main prey, snowshoe hares (Lepus americanus). We studied the seasonal variation of coyote diets and the dietary overlap between coyotes and lynx in a 512-km2 high-elevation study area in northwestern Wyoming. Dietary shifts by coyotes were documented during the winter, spring, summer, and fall from August 2006 through June 2008. Although lynx are known to primarily prey on snowshoe hares, lynx scats were also collected to assess their diet for comparative purposes. A total of 470 coyote scats and 24 lynx scats were collected, dried and analyzed. Mule deer (Odocoileus hemionus) was the predominant prey item for coyotes by percent occurrence (20.1%) for all 3 years combined, followed by elk (Cervus elaphus, 12.5%), montane vole (Microtus montanus, 12.0%), and snowshoe hare (8.0%). Snowshoe hares were the dominant prey item for lynx during the winter, accounting for 85.2% of all prey occurrences. Coyote use of snowshoe hares peaked in the fall (24.1% of all occurrences). We found little dietary overlap between coyotes and lynx during the winter months when lynx mainly fed on snowshoe hares and coyotes fed mostly on ungulates.

Coyote colonization of northern Virginia and admixture with Great Lakes wolves

Ecological invasions of generalist species often are facilitated by anthropogenic disturbance. Coyotes (Canis latrans) have benefitted from anthropogenic changes to North American ecosystems and have experienced a dramatic range expansion since the early 19th century. The region east of the Mississippi River has been colonized via 2 routes that have converged in the mid-Atlantic region during the past few decades. Coyotes using the northern route of expansion show molecular evidence of admixture with the Great Lakes wolf (GLW). We used noninvasive molecular techniques to detect the geographic origins of the recent coyote colonization of northern Virginia as a representative of the mid-Atlantic region and to detect signatures of admixture with GLWs. Of 455 individual canid scats screened, we sequenced a variable 282-base pair fragment of the mitochondrial control region from 126 coyote scats, assigned individual identities to samples using 6 microsatellite loci, and conducted phylogeographic analyses by comparing our sequences to previously published haplotypes. In 39 individuals identified in our scat surveys we detected 7 mitochondrial DNA haplotypes, all of which have been previously reported in diverse surrounding geographic localities. Phylogeographic analyses indicate multiple sources of colonization of northern Virginia. One common haplotype detected in northern Virginia is of wolf origin, indicating the presence of admixed coyotes and GLWs from the north.

Evaluation of fecal DNA preservation techniques and effects of sample age and diet on genotyping success

AbstractOptimal collection and preservation protocols for fecal DNA genotyping are not firmly established. We evaluated 3 factors that influence microsatellite genotyping success of fecal DNA extracted from coyote (Canis latrans) scats: 1) age of scat, 2) preservative, and 3) diet content. We quantified genotyping success by comparing rates of allelic dropout, false alleles, and failed amplifications among consensus genotypes. We used a panel of 6 microsatellite loci to genotype 20 scat samples, each of which was subjected to 3 age (1 day, 5 days, and 10 days post‐deposition) and 3 preservation (DET buffer, 95% ethanol [EtOH], and lysis buffer) treatments. Both sample age and storage buffer had a significant effect on success and reliability. Ethanol and DET buffer preserved fecal samples with similar efficiency, and both were superior to lysis buffer. Our analysis of DNA degradation rates revealed that samples collected as early as 5 days of age yielded DNA that was highly degraded relative to samples collected on day 1. We tested the influence of dietary remains on microsatellite genotyping by using scat samples consisting predominantly of insect prey (n = 5), mammalian prey (n = 9), or the remains of juniper (Juniperus spp.) berries (n = 6) and compared EtOH and DET buffer preservation efficacy. We observed a significant interaction effect between storage buffer and diet for the probability of a false allele in a polymerase chain reaction (PCR), suggesting that the optimal preservation technique depended on the food remains comprising the scat. Scats comprised of juniper berry remains were more reliably genotyped when preserved in DET than EtOH. Mammalian prey‐based scats were more reliable when stored in EtOH than DET buffer. Insect‐predominant scats were preserved in EtOH and DET buffer with similar efficiency. Although accurate and reliable results can be obtained from scats collected at ≥5 days of age, we suggest sampling design to include collection of scats &lt;5 days of age to minimize field and laboratory expenses. We suggest EtOH preservation for scats of obligate carnivores and of facultative carnivores with a diet consisting primarily of mammals. We suggest DET buffer preservation for animals with a diet consisting of plant‐derived foods. Lysis buffer protocols that we employed should not be used for fecal DNA preservation. © 2011 The Wildlife Society.

Plant productivity, predation, and the abundance of black-tailed jackrabbits in the Chihuahuan Desert of Mexico

The abundance of black-tailed jackrabbits ( Lepus californicus) can fluctuate dramatically. We used data from the Chihuahuan Desert to test the relative strength of top-down (predation) or bottom-up (food availability) limiting forces. Predictions for the top-down hypothesis were, 1) a positive relationship between coyote ( Canis latrans) and jackrabbit abundance (numerical response) and 2) a positive relationship between percent occurrence of jackrabbits in coyote scats and jackrabbit abundance (functional response). Predictions for the bottom-up hypothesis were, 1) plant productivity is directly related to precipitation, 2) jackrabbit abundance is positively related to precipitation and plant productivity, and 3) changes in abundance of jackrabbits over the reproductive season will be directly related to precipitation and plant productivity. We found a limited numerical response but no functional response of coyotes to jackrabbit abundance. Forb productivity was significantly related to annual precipitation levels ( r 2 = 0.69, p = 0.002). Grass productivity was related to annual precipitation ( r 2 = 0.34, p = 0.028). Jackrabbit abundance ( r 2 = 0.38, p = 0.002) and changes in abundance ( r 2 = 0.73, p < 0.001) were significantly related to precipitation and forb and grass productivity. We conclude that precipitation levels and plant productivity affect jackrabbit abundance more than predation levels.

Spatial and temporal patterns across an ecological boundary: Allochthonous effects of a young saltwater lake on a desert ecosystem

We documented changes in the abundance and composition of terrestrial flora and fauna with respect to distance from the sea edge and timing of large allochthonous inputs from the Salton Sea, California. We found significant effects that were most pronounced within 300 m of the shore, but extended 3 km inland via coyote scat deposition. The zone within 300 m of the sea had a higher density of vegetation with a distinctly different plant composition. The denser vegetation supported higher abundances of birds and reptiles. Coyotes exhibited spatial and temporal responses to marine subsidies of fish, while birds were likely subsidized by aquatic aerial insects. Top-down control, as well as dietary and habitat preferences, may have resulted in reduced number of ants, beetles, and small mammals near the sea. Species responses to the habitat edge appeared to be associated with life history, as the near shore habitat favored habitat generalists and shore specialists, while inland desert habitat favored many sand and open desert specialists. Ecosystem responses support current theories of allochthonous spatial subsidies and consumer-resource dynamics but were limited in scope, magnitude, and distance.

Foraging in the Landscape of Fear, the Predator's Dilemma: Where Should I Hunt?!

Under predation risk, prey species are more abundant in areas of low predation risk even at the expense of forage quality. As a result two predictions are possible, 1) predators should choose to hunt in areas with fewer but easier to catch prey than areas where they are more abundant but harder to catch; and 2) the frequency of prey species in the diet of predators using low risk areas should be greater than, or at least equal to, the diet of predators using high risk areas. To test these two predictions, we used data on coyote Canis latrans abundance and diet composition from two habitats in the Chihuahuan Desert of Mexico that have different abundances of jackrabbits (Lepus californicus) and rodents. We used the number of coyote scats found in transects in the two areas to assess coyote abundance and analyzed the contents of these scats to determine diet composition. We found significantly more coyote scats/yr (22.6 ± 4.7 (SE) vs. 12.2 ± 2.4 scats/yr, d.f. = 7, paired t = 3.80, P = 0.007) in the habitat with less jackrabbits and more rodents. However, the percent occurrence of jackrabbits (54.3 ± 6.7% vs. 60.1 ± 7.7%) and rodents (32.6 ± 6.5% vs. 30.1 ± 6.0%) in coyote scats did not differ between the two habitats. These results supported both the above cited predictions and the hypothesis that prey vulnerability can influence habitat use by coyotes.