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Since the 1800s, eastern North American landscapes have experienced extensive anthropogenic changes. Large swaths of forest were timbered, innumerable roads and railways were constructed westward, and extirpation of large apex predators altered the faunal communities that once existed there. Among these large predators, the gray wolf (Canis lupus) all but vanished from the landscape due to intense persecution. Some species, however, were able to adapt and thrive on this changing landscape. The coyote (Canis latrans) is one such example. As deforestation and transportation networks expanded westward, coyote ranges began to expand eastward. This smaller canid that had evolved in the open grasslands of North America was able to navigate the deforested east and fill the predatory niche left vacant by gray wolves. During the coyote range expansion, hybridization among coyotes, wolves, and domestic dogs began to occur. Dispersing coyotes that came in contact with isolated remnant populations of gray wolves or free-ranging dogs occasionally interbred, leading to eastern coyote populations that preserve genetic remnants from both gray wolves and domestic dogs. This genetic introgression was first discovered in the northeastern United States in the 2010s, but more recent works have expanded the zone of introgression into the Great Lakes region of North America. Despite increasing understanding of the coyote-wolf-dog contact zone, Ohio’s coyotes were previously believed to have not hybridized with other canids. However, a few studies suggested that Ohio coyotes also preserve evidence of hybridization with domestic dogs and wolves. This dissertation expands on the smaller pre-existing dataset to identify genetic markers that would confirm admixture with domestic dogs and wolves in Ohio’s coyote ancestry. I do this by first providing evolutionary context for the genus Canis exploring the anastomosing histories of hybridization events among coyote, wolf and domestic dog populations. I then conduct analyses to identify gray wolf and domestic dog genetic markers in a robust dataset of Ohio coyotes. Next, I analyze whether natural and/or anthropogenic landscape features predict the prevalence of gray wolf and domestic dog genetic markers examined for the Ohio coyote sample. In the final chapter, I explore how genetic introgression of gray wolf and domestic dog impacts coyote interactions with bobcats (Felis rufus), another mesopredator in Ohio.The coyotes sampled in this dissertation reveal extensive evidence of historical hybridization with both gray wolves and domestic dogs, providing further support that Ohio is part of the coyote-wolf-dog hybrid zone. Landscape factors including transportation networks and forest cover predicted the relative proportion of wolf or dog alleles in the Ohio coyote dataset. Finally, the presence of wolf and/or dog alleles did not observably alter behavioral relationships between coyotes and bobcats. This dissertation helps to untangle complex relationships among genetics, landscape, and behavior in a coyote-wolf-dog hybrid zone, documenting historical hybridization among canid species and offering future directions for research and management.

The domesticated dog (Canis familiaris) is the most popular household pet in America. There are approximately 42.5 million dogs kept as pets in the United States. Despite dogs being the most popular pet, methods for dogs’ age determination are limited and lack precision. After eruption of the final permanent teeth at about 7 months of age there is no quality method for determining age. Characteristics such as development of cataracts, tooth wear, and acquisition of grey hair become the leading factors in age determination; however, the aforementioned factors are variable in all dogs. The use of a pulp cavity/tooth width ratio, measured using dental radiographs, was applied to Canis familiaris to determine a more reliable method for determining age in dogs. This, more accurate method for determining age in dogs, will allow a reduction in shelter euthanasia and allow veterinarians and pet owners to more easily determine treatment plans.

Fighting can be extremely costly in terms of energy use and potential for injury or death. Therefore, the ability to accurately assess a threat is advantageous, allowing an animal to retreat from conflict if its chances of winning are low. Game-theoretical models of agonistic behavior suggest that animals should base decisions about conflict escalation on an assessment of their opponent’s fighting ability or resource-holding potential (RHP). Individuals can assess an opponent’s fighting ability relative to their own using a number of physical and behavioral cues. Some aggressive displays, including some vocalizations, are believed to function as such cues, or advertisement displays, of an animal’s RHP. Studies of advertisement displays have typically focused on contests between individuals. However, just as correct assessment of a rival is advantageous in conflict-escalation decisions between individuals, it might be expected that correct assessment of group size would be an important criterion in determining potential costs in contests between groups. Social animals would benefit from accurate perception of group size when assessing the fighting ability or RHP of a competing group in the same way that individual competitors benefit from assessment of their single competitor’s size and strength. A number of studies have been published in recent years investigating group-level assessment in agonistic contests. These studies have focused on territorial vocal signals of various group-living species to determine whether competing groups glean information about group size from these acoustic signals and adjust their behavior in a manner consistent with the predictions of game-theoretical models of agonistic behavior. The goal of this thesis research was to determine whether group-size information is available in the group yip-howl of the coyote. The approach to this investigation was two-fold: a) conduct a field experiment with radio-collared coyotes and measure their movement and vocal responses to playbacks of group yip-howl recordings from different-sized groups, and b) analyze the acoustic features of the coyote group yip-howl. The aim of the field playback experiment was to measure the responses of coyotes to the agonistic vocalizations of a potential competing group. Acoustic features of the coyote group yip-howl were analyzed to better understand the potential cues contained in the signal that might allow for the perception of group size.