Coyote Ecology in South Carolina (PhD work)
The first record of a coyote in South Carolina (SC) was in 1978. Coyote populations have grown since then, and they are now established in every county in SC. Anytime an animal (or plant) shows up somewhere new, it’s a good idea to figure out how it will affect the existing system. In the last decade there have been a flurry of studies in the southeast, most aimed at understanding how coyotes are impacting white-tailed deer, an important game species. So far it’s been a mixed bag, some studies have found that coyotes do reduce deer recruitment (by eating fawns), but others have found that their impacts are less significant. Current gaps in knowledge exist around how coyotes respond to deer movement (if they do at all), under what conditions will coyotes predate adult deer, and how are coyotes influencing smaller carnivores (like bobcats and foxes). The overarching question is what role do coyotes play in the southeast? Do they exhibit the traits of an apex predator?
We are working in the Piedmont region of SC. Our core methodology involves capturing and placing GPS collars on coyotes, does, and their fawns, all in the same area. Not only do GPS collars help us understand movement patterns and resource requirements of our study animals, since they are all on the landscape concurrently, we can study their interactions. This is particularly useful when trying to understand why some fawns are killed by coyotes and others are not. Core questions are how is fawn mortality related to coyote behavior, doe behavior, or habitat?
Working up a male coyote [CMC-14] in December 2018. We restrain their legs and mouth, no sedation needed. Photo by David Jachowski.
In addition to the GPS collars, we have deployed a wildlife camera array across our study area to help us answer other questions. Namely, what is the density of deer and coyotes in our study area? And how are different species using the landscape across space and time? I.e., does the presence of coyotes influence the presence of other smaller carnivores? We are also conducting coyote scat [poop] surveys to quantify what coyotes are eating throughout the year.
A coyote with what appears to be part of a deer in its mouth. There is no way to know if this deer was predated or scavenged. Photo by Alex Jensen.
My poster from American Society of Mammalogists 2019 can be viewed here: ASM 2019 Poster
A news release about project (from March 2019) can be viewed here: https://newsstand.clemson.edu/mediarelations/clemson-researchers-work-to-understand-impact-of-coyotes-on-states-deer-population/
Wildlife-Highway Interactions in California (M.S. work)
Roads are not good for most animals. It’s been estimated that a staggering 1,000,000 vertebrates are killed on U.S. roads every day (2), which can be a significant source of mortality for some species (e.g., Florida panther; 3). Hitting (large) animals with a vehicle is bad for people too; every year deer alone cause 150-200 deaths, ~29,000 injuries, and ~$1,100,000,000 in property damage (4,5). In addition to direct effects on wildlife, some species avoid roads, which can reduce genetic population health. Wildlife exclusion fencing (see below) has been shown to reduce wildlife-vehicle collisions (6), but likely increases the barrier effect of roads. Therefore, fencing combined with safe passage (usually in the form of undercrossings) has been found to be the most effective method for reducing collisions with wildlife while maintaining ecological connectivity.
This project was along Highway 101 on the central coast of California, near San Luis Obispo. In 2009, a wildlife exclusion fence was installed which included 4 jumpouts (see below) and retrofitted culverts. The goal of my thesis research was to quantify wildlife use of these structures. For the jumpouts, we wanted to know if wildlife were using them to escape the highway corridor (as intended), and how often they were using them to access the highway (not what we wanted). For the undercrossings, we wanted to understand which factors were important predictors of use. We documented wildlife use of infratructure using wildlife cameras.
Left: One of four jumpouts designed to provide an escape opportunity for animals trapped within the fence. Right: This portion of Highway 101 bisects the Los Padres National Forest, an important wildlife linkage connecting southern and northern California. Photos by Alex Jensen.
What we found
Deer were 88% (n=1015) of the wildlife detections at the jumpouts, and jumped out ~20% of the time when given the opportunity. By identifying individuals we found that two groups of deer accounted for 41% of all deer detections. The two groups appeared to incorporate the jumpout into their daily routine (see below). Few groups (14.6%, n=198) jumped out during their first visit to the jumpout, but of the ones that returned at least 3 times, 29% (n=17) jumped out at least once. We did not find evidence for sex- or age-based differences in jumpout use. Only gray fox and house cats were documented using the jumpout to gain access to the highway corridor.
Left: A male deer about to jump out. Right: A doe and yearling who liked to hang out at the jumpout. Sometimes for HOURS.
For the undercrossing portion, we focused on mountain lion, black bear, deer, and bobcat activity in 11 undercrossings along our study area. We detected mountain lions too infrequently (32 times) to draw conclusions about their selection patterns. Bear were detected 142 times, and used undercrossings that were in forested habitat more than others. Deer almost exclusively used larger underpasses, and bobcats selected for undercrossings with good cover leading to the entrance.
Left: Mountain lion looking at the camera in a 4 foot high culvert. Right: Family of gray foxes passing through the same culvert. Photos by Alex Jensen.
Overall, we recommend funding be in place to monitor wildlife crossing projects such as these for a minimum of 3 years to account for acclimation and individual variation in use. Further, GPS tracking technology can provide fine scale insight into how animals are interacting with roads.
A young buck equipped with a GoPro demonstrating how to use the jumpout.
My master’s thesis entitled Crossing Corridors: Wildlife use of jumpouts and undercrossings along a highway with wildlife exclusion fencing can be downloaded here: https://digitalcommons.calpoly.edu/theses/1939
3) Forman and Alexander 1998.
4) Mastro et al. 2008.
5) Stull et al. 2011.