Controlling coyotes — Is it worth the effort?
By mid to late September, the majority of white-tailed deer fawns have hit the ground in Louisiana and other areas of the Southeast. The exact time frame corresponding to this occurrence varies according to the breeding dates for various deer populations, which undergo an average gestation period of 202 days.
Individuals responsible for managing deer herds in our state look at the success of pregnant does in giving birth and weaning healthy offspring as the first step in the management process. A measure often considered to increase this success involves predator control programs, often targeting what is perceived as the No. 1 predator on white-tailed deer outside of man — the coyote.
Coyotes, which are classified as outlaw quadrupeds, can legally be taken year-round in our state during daylight hours by anyone possessing a valid Louisiana hunting license. This status further strengthens the belief among many that they are a serious threat to wildlife populations.
As with most predator-prey relationships, however, there are other factors that must be considered.
Research has shown that deer are an important food source for coyotes based on the frequency that deer hair is found in coyote scat. Fawning season and hunting season are the two primary periods when this occurs, with evidence of very little use at other times.
A peak during fawning season is expected from an opportunistic predator such as a coyote, while peaks during hunting season represent how coyotes utilize deer from a carrion food source. Wounding losses and discarded processing parts provide the majority of venison consumed during the open deer season.
Predation on healthy, adult deer in the southeast is a rare occurrence, even though many hunters, who have spent time on a deer stand, have witnessed the passing of a deer followed by a coyote in hot pursuit.
An important fact to remember is that coyotes are omnivores, feeding on a wide variety of plant and animal matter. Their food source will shift to whatever is most easily attainable and they will seldom attack an animal such as a healthy white-tailed deer that can cause them injury, especially when other foods are available.
Coyotes do kill fawns and some experienced individuals have been witnesses to take-down of adult deer. However, when asked if this predation has a significant impact on deer populations in the broad scheme of things, the answer is usually no.
There have been studies showing that coyote predation on fawns can reach a point which requires a significant reduction in the antlerless deer harvest to offset these predation losses. In many instances, however, managers can strive to mitigate against these losses by striving to manipulate land to provide for the maximum acres of prime fawning habitat scattered within a given area. When this is provided, fawning will occur over a wider range, lessening the chances for coyotes to find fawns concentrated in small areas.
Fields of tall grass and forbs provide excellent cover for does to hide their fawns and the vegetation serves to disrupt wind movements that carry what little scent these young deer omit. These areas also provide excellent habitat for rabbits, mice, snakes and other small animals whose population increase serves as an alternate food source for coyotes.
Research has also suggested that fruit-bearing plants such as persimmons and blackberries also tended to buffer the impact of coyotes preying on deer, rabbits and other animals.
Other management factors to consider involve achieving an appropriate harvest of antlerless deer to achieve a more balanced sex ratio. This in turn will push the breeding cycle into a narrower time-frame, with the majority of does getting bred during their first estrus cycle.
Fawns conceived under these conditions will drop within a much narrower time period. This increase in potential prey over a short period is known in ecology as the “satiation principle.” Predators are overwhelmed with potential prey in such a manner that they cannot effectively consume all the fawns before the fawning season ends.
The placement of deer feeders and salt licks near areas of thick cover should also be avoided as such situations provide possible ambush sites for coyotes to take advantage.
If still considering lethal control on coyotes, it should be noted that the battle is one that will most likely be lost. Coyotes exist in a social structure that when hit with population reduction measures, tends to respond in such a way as to greatly ramp up reproductive capacity.
Females will give birth to as many as 10 to 12 individuals in these cases instead of the usual five or seven. Furthermore the population is now shifted from older animals that are regulating themselves — often killing each other to maintain dominance and territory — to younger individuals in greater numbers, often having a greater impact on deer populations.
The prowess and cunning of the coyote is noted by one of the earliest written accounts of their existence when William Clark of the famed Lewis and Clark expedition made the following entry in his journal on Aug. 12, 1804 ... “A Prairie Wolf come near the bank and Barked at us this evening; we made an attempt but could not git him, the animal barks like a large fierce dog.”
Captain Clark mistakenly used the name “prairie wolf,” since coyotes at that time were unknown east of the Mississippi River as they had not yet begun their eventual takeover of areas that were being vacated with the demise of the red wolf.
The point, however, is that more than 200 years ago, this coyote managed to avoid becoming a scientific specimen just as many others in the future avoided similar fates for different reasons. (Dr. Don Reed is a retired forestry and wildlife specialist with the LSU AgCenter. You can email him at firstname.lastname@example.org.)