Deer Dynamics: Carnivore Predation
Are whitetails becoming elusive and more difficult to hunt? Are deer sightings down? If so, maybe you are facing an obstacle that will frustrate your hunting opportunities – the American coyote.
The survival rate of a deer fawn depends not only on nutrition but the mother’s maternal guidance. Her vocal commands play a major role in teaching the fawn when and where to bed.
In the near distance is a female deer. She is highly alert and somewhat frantic as the coyote finally enters her core area. Surprisingly, she approaches it, and then begins to dart in erratic circular moves. Next the bold doe actually jumps toward the puzzled canine. She then snorts loudly and stomps her left front hoof.
The two animals momentarily stare at one another. Suddenly the doe charges and kick swats toward the coyote. Confused, the opportunistic scavenger evades her assault. After several more forward charges and loud snorts, the coyote slowly retreats from the doe’s domain. Her newborn survives another lurking predator.
Typically, whitetails swiftly evade predators — especially maternal females that attempt to lure predators away from their bedded offspring. However, there are incidents where parenting does can become aggressively defensive, actually confronting predators in an effort to protect their fawns.
Whitetail fawns are extremely vulnerable for roughly the first six weeks of life. Malnutrition, disease and even abandonment are harsh realities that can lead to mortality. Predators such as black bears, bobcats, coyotes and even wild hogs are the deer fawn’s biggest threats.
Although a fawn relies on camouflage cover through constant motionlessness in the bed, the success of its survival also depends on nutrition and its mother’s maternal care and guidance. If one of these factors fails, then a roaming predator can gain the upper hand.
In contrast, how effective are predators in taking down mature whitetails? Unless healthy adult whitetails are in thick snow or sliding on ice, it is extremely rare for predators to attack and kill adult deer. Northern timber wolves tend to have more success than other predators, simply because they are effective, organized pack hunters; coyotes, bears and bobcats are not.
As for newborn deer fawns, the pendulum swings the other way — to the predator’s advantage. Although there is controversy among biologists as to how much influence coyotes have on fawn mortalities, research is revealing more about this predator than initially known.
A biological study conducted by the Pennsylvania Game Commission concluded that various predators such as coyotes, black bears and bobcats account for 23 percent of fawn mortality. Out of 49 newborn deer, coyotes led the way for predation of 18, followed by bears taking 16 fawns and bobcats only three.
Yet these statistical numbers showed that overall, predation isn’t putting the deer population in jeopardy. Whitetails are still able to thrive despite predators and seasonal harvest by hunters in the Keystone State.
Other scientific studies also came to the conclusion that coyotes impact deer fawns more than other predators. Yet the degree and number of fawns taken fluctuates from year to year. Also, the region and type of habitat determines how many fawns fall to predation.
Even though several states are not seriously affected by coyotes, some geographical areas are and others eventually could be as coyotes continue to expand their range throughout the South. For example, overpopulated coyotes in South Texas periodically have a significant impact on whitetail fawns. Unmanaged coyotes forming high densities can jeopardize fawn recruitment. Combine this loss with drought, hunter harvest and other environmental conditions, and sportsmen can have limited hunting opportunities for a couple of seasons.
But the question remains if these events will linger too long and if certain areas need to implement predator control or change harvest quotas due to predators adversely effecting whitetail populations.
Hunting by sight, smell and hearing, the coyote’s carnivorous instincts in time become enhanced — increasing the odds of fawn predation. Fawns born in low-cut agricultural fields are highly vulnerable. If the newborn survives the raking and baling of the late spring to early summer mowing season, the low-cut forage easily exposes the infant to roaming coyotes.
Coyotes will sit along the woodland edges adjacent to a field or slowly traverse a small tributary — intensely waiting to spot any movement or hear any cries of distress. If a fawn is malnourished or the parenting doe stays gone from its side for too long, the fawn is more inclined to vocalize a “bleat” or “bawl.”
Once a coyote moves in, the response of the mother doe may have an effect on the predatory outcome. Typically, female deer try to lure predators away by fleeing opposite of the fawn’s bedding site. Here, the fawn instinctively relies on stillness, camouflage and minimal odor. The doe’s flight behavior is an attempt to draw the predator toward her and away from the bedded offspring.
With inexperienced predators, the evasiveness of the doe’s innate behavior works, but the more a predator has success, the easier it becomes for it to locate prey.
Another problem posed against the fawn-rearing doe is that just before birthing the pregnant female breaks away from the herd’s social protection, finding a secluded area for birthing and bedding her newborn fawn. This natural act on the part of female deer can add to the fawn’s vulnerability but also its likelihood for survival.
The presence of coyotes alone can reduce the overall visibility of whitetail deer, which can affect scouting and hunting opportunities for sportsmen. Some coyotes tend to waste time and energy chasing adult deer — particularly during the nighttime and pre-dawn hours. It is a merry-go-round of chasing. Whitetails are in and out of cultivated fields, utilizing whatever available cover they have such as high grasses and thick underbrush.
Occasionally, more than one coyote runs deer — sometimes up to three — but this is extremely rare. Here again, coyotes are by no means effective pack hunters like wolves. Nonetheless, all this physical exertion can put stress on the whitetail, negatively affecting impregnated and nursing does as well as hindering bucks from developing good antler growth.
So how can one determine if coyotes are adversely affecting the local deer herd? Examining coyote scat to see what they’re eating and if and where scat remains are increasing is one way to determine their degree of activity. Fawn observations also help to equate if there is a coyote problem and if harvested single does are not lactating.
So, what if coyotes are reducing deer numbers and keeping the herds less visible? Well, depending on the degree of impact, it may not be such a negative aspect. Keeping a stable deer population is necessary, and the coyotes’ pursuit works to make whitetails more elusive. Lands with limited hunting can benefit here as coyotes work to moderately hinder excessive deer numbers. However, roaming canines can undesirably affect deer numbers and hunting opportunities.
For example, a 3,000-acre tract in Georgia was beginning to experience a loss in the number of deer sightings and deer harvested. This particular property had a high density of coyotes, and in just three weeks, a professional trapper captured 30 coyotes.
Coyotes need to be managed despite recent claims that the animals are able to self-regulate and control their numbers through natural acts such as starvation, cannibalism and dominant hierarchy dispersal. This is the theory of natural regulation where man is eliminated from the predator food chain. It is not proven scientifically, and is highly controversial.
Ultimately, man and the traditions of hunting and trapping need to be incorporated into a management agenda if coyotes are going to be effectively controlled. Trapping is the most effective way of predator control, and should be done in the fall and winter. The only problem here is that these seasons are also deer hunting times, and trapping activities could conflict with hunting opportunities.
Ensuring that the land has sufficient cover such as thick patchwork acreage of native bluestem and Indian grass can be a plus for whitetail concealment. Another alternative if seeding natives isn’t feasible is just to allow particular areas to grow and either bush hog or burn the tracts so the forest doesn’t take over in time.
Using records of harvest, sightings and trying to manage the herds with an even buck-to-doe ratio will help. Hopefully, the majority of females will breed within a two-week period, and the birthing of most fawns the following year will occur within a two- to three-week period. The theory is so many fawns are born at the same time that predators will not be able to prey upon them all — allowing a good number of infants to survive. Also, if fawns are born when prime vegetative food sources are available, sometimes predators get pre-occupied with these foods. Here, they spend more time eating and less time searching for fawns.
If whitetails share habitat with cattle, horses and mules, the advantage here is that the presence of large domestic animals can sometimes discourage coyotes. On rare occasions, coyotes will attempt predation on domestic young, but if cows and horses are nearby, their defensive stampedes are usually too much for the coyote. Deer learn to mingle and feed around cattle, mules and horses, using them as a type of protective shield from predators.
Once the deer fawn survives the onslaught of predators, it quickly grows as learning experiences are imprinted and instinct develops. These events are vital for the fawn’s life and maturity — next month’s topic.
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