John's Journal...

Coyotes: Helpful Predators or Deer Killers

More on How Coyotes Have Affected Deer Herds in Different States

Editor’s Note: Here are some more examples about how coyotes affect the deer herds in their states.

Click to enlargeNew Mexico
"Depending on who you ask, the answers will vary," Barry Hale, the Deer Program coordinator for the New Mexico Department of Game and Fish, explains. "Most of the hunters and landowners I've spoken to indicate that coyotes are the major cause of low deer numbers - either because they've contributed to the decline in deer populations experienced during the last few decades and/or they've prevented deer populations from increasing. Others say coyotes have a positive effect because they weed out the weaker and/or sicker deer. Some will say their presence is benign. New Mexico probably has examples of all situations, but no hard data exists to support any of these positions.

"Most wildlife biologists would say that the interactions among habitat, the population status, the environment at specific locations will determine whether coyotes have any local effect on the deer herd population. Coyote predation is a cause of deer mortality, but so are starvation, disease, abandonment and accidents. All of these can be attributed to a more-ultimate cause of habitat loss. Therefore, attempting to remove or control coyote populations in this area won't make a difference because these deer will likely die from the other causes." Hale also mentions that coyotes may provide some benefits in that they may control populations of other species that can spell trouble for humans and/or other wildlife, such as rodents that carry diseases like the plague or hantavirus. "The coyotes find that adult deer are the most vulnerable during periods of weakness, such as after the rut, during and/or after winter. Too, fawns, and their mothers, are vulnerable during and immediately following the fawning period."

Rhode Island
"Rhode Island has an abundance of coyotes in the presence of abundant deer herds," Lori Gibson of Rhode Island's Department of Conservation, explains. "And, we have a public that is not tolerant of either. The fawns are most susceptible to the coyotes, but we get some reports from hunters in the winter of coyotes running deer when conditions are ripe."

Tennessee Click to enlarge
"Since coyotes have an insignificant effect on the statewide herd, they can't be viewed as positive or negative," Daryl Ratajczak, wildlife biologist, says. "The impact is literally negligible on the overall herd. Coyotes are just one of many obstacles deer must face throughout their life cycle. However, on certain leases or in localized populations where coyotes are prevalent and the deer are intensely managed, coyotes may have some effect. For example, on a small property where deer herds are kept in check far below carrying capacity, if a coyote kills five fawns, and four of them are females, this fact will positively affect the herd (maintain its balance). If, however, that property is managing the herd for more bucks, then the coyotes may have a negative impact if they kill a disproportionate amount of male fawns. In summary, coyotes have no positive or negative effect on the overall deer herd but can affect a localized population, depending upon the purpose of the herd's management.”

“Coyotes are opportunistic and will eat a deer anytime the opportunity presents itself. With this in mind, coyote predation on deer is most prevalent during the fawning season (July/August). However, stomach-content studies reveal coyotes feed most heavily on deer during the months of November and December due to the widespread availability of gut piles left during the regular gun hunting seasons for deer."

Deer biologists from the Texas Parks and Wildlife Department feel coyotes have had both positive and negative impacts on white-tailed deer in Texas, depending on the situation and the region. On the positive side, coyotes aid in keeping white-tailed populations in check in the portions of the state with coyote populations. Predators such as the coyote are members of a healthy ecosystem. Too, coyote predation has a positive effect on the mule-deer herd in west Texas because coyotes play a major role in keeping an expanding deer herd from creating a deleterious effect on respective habitats throughout Texas. Click to enlarge

Mitch Lockwood, leader of Texas Parks and Wildlife Department's (TPWD) White-tailed Deer Program, and his Wildlife District Leaders have compiled the following information. "Portions of Texas with extremely-high coyote densities feel the negative impact of coyotes through overgrazing of ranges to the point of reduction of fawning cover and reduced densities of 'buffer' species (rats, small mammals, etc.) normally associated with adequate ground cover. Range-management efforts will help reduce the impacts of such on whitetail populations. In the parts of Texas that practice white-tailed deer management, managers view each fawn as a potential addition to the marketability of that deer herd. Often, managers use high-protein feeding operations and predator-control efforts to maximize recruitment to the deer herd often to the detriment of the native habitats in which those deer herds exist. Some sections of Texas with historically-low recruitment and heavy hunting pressure see coyotes as competition for the deer resource. Past studies have indicated that in the Post Oak Savannah of Texas, predation may be attributed to half of the mortality of fawns with much of that predation directly attributable to coyotes. In regions with high-coyote densities, coyotes may impact adult deer survival, notably in the post-rut period when bucks are in a run-down condition.

Too, according to the TPWD's biologists, "Coyotes themselves may or may not be the problem. If hunting pressure is adequate to control deer numbers, or in fact there is more hunting pressure than deer available, then perhaps few coyotes will be a benefit. However, in many portions of the state, such as the Hill Country where coyote populations historically have been controlled, their impact may be viewed as positive to managers. Coyote predation in many parts of Texas may be viewed as a symptom of the true problem of inadequate-habitat management to reduce the impacts of such predation. Additionally the perceived market for whitetails may directly influence the viewing of the coyote as either a positive impact or a negative impact, notably in this day and age when feeding programs and predator control are viewed as the 'panacea' to deer management. Coyote numbers in the Tans Pecos Ecoregion, located in west Texas, are dynamic because they follow the existing prey base. As habitat conditions improve, subsequent improvements occur with the prey base, showing a direct relationship between an improving prey base and improving predator numbers."Click to enlarge

W. Matt Knox, Deer Program supervisor with the State of Virginia, explains that, "In the western part of the state, we very frequently get comments and questions from deer hunters regarding the impact of coyotes on the deer herd. These hunters frequently perceive coyotes as having a negative impact. It should be noted, however, that the deer kill in this part of the state has been at record levels for the past 3 years. However, there has been no decline in deer herds anywhere in the state that can be attributed to coyote predation. I would hypothesize that coyotes feed on deer primarily at three times: fawns during the fawning season, wounded/crippled/unrecovered deer during hunting season and deer in very-poor conditions during late winter/early spring. Luckily there are very few areas or deer in Virginia that meet this criteria." Knox mentions that due to the negative impact of coyotes on agricultural interests, he thinks the state could use fewer coyotes. "Our hunter-survey data clearly demonstrates an increasing coyote population in Virginia."

"It's hard to tell," Reg Rothwell, a biologist with the Wyoming Game and Fish Division, states. "Coyotes certainly prey upon deer, but there are other factors influencing deer populations at the same time.  A number of studies have demonstrated that, although coyote predation is the cause of death, the ultimate cause is something different.
"Habitat is most-commonly identified as the factor that predisposes animals to predation, especially inordinate levels of predation, which can be poor escape and hiding cover or poor nutritional condition. The Rocky Mountain region has experienced a drought in years past, which has affected vegetation. This is on top of habitats that have been affected over the longer term by the absence of natural fire cycles and over-utilization of woody and non-woody plants. Those long-term influences have generally left vast areas of the West in poor condition (dense, decadent shrub communities with nutritional value that is barely maintaining the nutritional plane of deer). In the shorter term, human conversion and use of prime (especially winter) habitats through oil and gas development, housing and associated development, increasing winter recreation, etc. are growing influences.

Biologists and outdoorsmen can improve things for deer with improved reproduction, better survival and predator control, but it's expensive and has to be carried out intensively forever. Money would be better spent improving, then conserving habitat. Then predation of any type would be generally immaterial, and all wildlife would benefit. Of course, there are many who passionately believe coyotes are THE problem and are continuing to search for any shred of evidence to support that belief. This is not to say that coyotes aren't a problem in certain places, and that some predator control, done surgically, wouldn't help." Rothwell believes coyotes prey and feed on deer year-round, but probably more so during and immediately following fawning. "I think our lands can handle the number of coyotes we currently have, but any more would exceed the carrying capacity of the land," Rothwell says.

Check back each day this week for more about "Coyotes: Helpful Predators or Deer Killers"

Day 1: A Deer Hunt Ruined
Day 2: Why Coyotes Spread Across the U.S.
Day 3: To Shoot or Not to Shoot Coyotes
Day 4: How Coyotes Have Affected Deer Herds in Different States
Day 5:More on How Coyotes Have Affected Deer Herds in Different States


Entry 457, Day 5