A study on coyotes has been underway in Bath County for over three years now. One reason for the study is to see what impact coyotes may be having on the decline of the deer population in the area. There are questions about how many coyotes there are here, where they are exactly and what they are eating. Now researchers are analyzing the data they’ve collected and a picture is starting to emerge.
Dana Morin is a Ph.D. student at Virginia Tech (Virginia Polytechnic Institute & State University) and a graduate research assistant on the Virginia Appalachian Coyote Study.
“There were definitely some things that we weren’t expecting,” says Morin. “We knew that coyote density probably wasn’t very high in Bath County, because it’s forest habitat. But it was actually some of the lowest densities that have been recorded for forest habitat. So, for example, kind of the mean density that you find in forest habitat is about one and a half coyotes per square mile and we’re actually much lower than that in Bath County. It’s actually about less than one coyote for every two square miles. So we found out the densities were a lot lower than we thought. We also found that home ranges were much larger than expected as well. So individual coyotes are traveling a lot more than we expected, just over the course of a day or a week, and this results in, kind of, maybe the impression that coyotes are at a higher density than they really are. For example, you may hear a family group of coyotes on one ridgeline one day and then hear them on another ridgeline another day and you may think it’s two different groups, but it may actually be the same group because they’re just traveling so much.”
Over a period of two years, nineteen coyotes were trapped and fitted with GPS collars that tracked their movements. And scat was collected and analyzed to figure out the coyote density and to see if the coyotes were eating deer.
“So from the scat I can identify different individuals using genetics,” says Morin. “Based on the number of times I see each individual detected through scat, I can start estimating how the population is changing over time and what the general densities are. It seems that in Bath County coyotes are regulated in the same way that they are across most of their range and that’s actually through competition for space and resources and not mortality. So, for example, the mortality is really, really high in Bath County. Sixty three percent of the coyotes we collared were killed within the first year of being captured. But the population density isn’t decreasing. And that’s because mortality doesn’t really have an effect on population density, because their reproduction increases in response to increased mortality.”
And while this is a coyote study, it’s turned out that the methods used to collect data have provided information on other predators too.
“We were surprised that the bobcat density seemed to be higher than we expected,” says Morin. “When we look at scat, and we identify it visually, often if we see things like deer hair in scat then we assume that maybe it’s coyote. But it turns out a lot of times that might be bobcat scat instead. Part of my job was to take samples from all the scat and then identify what species it came from using DNA.”
Morin’s dissertation as a Ph.D. student will be the final report on this study along with a master’s thesis by David Montague, who is studying the diet of bobcats, coyotes and bears. The Virginia Department of Game and Inland Fisheries is one agency that will review their findings for it’s work.