Coyote Predator Control Has “Modest effect” On White-Tailed Deer Survival
Predator control in the United States is controversial and the research is ongoing.
Predator control in the United States is controversial and the research is ongoing. Intensive predator control has been implemented effectively in isolated populations of Big Horn Sheep and Mountain Goats among others. However, even in isolated populations of these prey animals, long term intensive predator control is required to positively influence the prey population. This level of control is often too demanding for the average hunter to engage in.
A recent study in the Journal of Wildlife Management conducted by the USDA over seven years in South Carolina has shown how futile even intensive coyote management can be.
USDA researchers engaged in a seven year project to understand the effects of intensive coyote predator management on white-tailed deer fawn recruitment. Their goal was to try to understand a) how often coyotes gobbled up deer fawns, and b) if that predation level could be decreased by intensive coyote removal.
For four years, the team passively observed the predator-prey dynamics of a 332km^2 study site in the Savannah River area of South Carolina. Following the four years of observation, the team then removed ~78% (removed 474 coyotes during treatment period) of the coyote population for the following three years. They quantified white-tailed deer fawn predation by collaring 216 fawns and used solid statistical methods to reach their results.
The team found that although their initial efforts did see a temporary increase in fawn recruitment, the overall results were not statistically significant. Interestingly enough, they also found that vegetative cover did not have any effect on fawn mortality. That is, whether the fawns were hidden in grass or in heavy chaparral, did not appear to have any effect on their survival. This could mean that Coyotes use their nose to hunt more than their eyes, but given the fact that fawns are almost completely devoid of scent, this hypothesis needs more research.
This is an excellent study that has implications for the predator control of coyotes in the United States. Granted, the team did not completely remove coyotes from their study area (only 78%). Their inability to completely remove the coyotes using trapping is predictable because of the coyote’s well documented learning abilities. The study concluded by saying that coyotes were an “additive mortality factor”, meaning there were other more significant causes of fawn mortality.
This study can be looked at in a variety of ways. Our primary take away is this: Control the coyote population all you want, but if you’re doing it to improve your local ungulate population, you may want to to consider other factors.