https://www.google.com/url?rct=j&sa=t&url=http://www.outdoorlife.com/blogs/game-changers/does-predator-control-really-work-science-behind-hunting-coyotes-and-other&ct=ga&cd=CAEYACoSNTU1MDgxNDMwOTk0OTUyNDMyMhplYzQ0NDQ0NjRjOGI2YWExOmNvbTplbjpVUw&usg=AFQjCNFhtIR0IQKmkBaFZCClqC-XT12IjQ
t's difficult to determine whether a coyote actually killed an animal or was just scavaging. Frair said. "Of 62 deer carcasses found in our study that collared coyotes had visited, we could determine cause of death at 39 and only 3 of those were actually killed by coyotes. That means less than 10 percent (1 in 10) of the carcasses a hunter sees in the woods might be caused by a coyote.
March 28, 2016
Does Predator Control Really Work? The Science Behind Hunting Coyotes and Other Predators to Protect Game Animals
by Dave Kramer
Wolf with a caribou hindquarter in Denali National Park. Photograph by Ken Conger / National Park Service
We often explain our passion for hunting coyotes and wolves as wildlife management. By killing wild carnivores, we’re protecting the prey species, like deer and elk, that we love to hunt.
But are we really making an impact on ungulate survival when we target predators?
It turns out the answer, like that of so many questions in wildlife management, is situational. At times, controlling predator populations is a sure-fire way to increase survival of prey species.
Other times, not so much.
Part of the dynamic is our perception of population abundance on both sides of the prey/predator spectrum. For sure, predators are on a comeback across the United States. Bears, wolves, and mountain lions are reappearing in states where they were once extirpated, coyotes and bears are frequently sighted in suburban environments, and threatened populations of carnivores are being removed from government protections.
At the same time, regions are experiencing declines in prey populations like deer and game birds. The natural instinct is to blame prey declines on the recent increases in predators. In some instances predators may be responsible for the decline, and in other cases it may be environmental change (for example, drought). In some regions, prey species have been overabundant due to the lack of predators and as predators make a comeback, the prey is put in check. To investigate whether predators are impacting prey populations, researchers are conducting research involving predator exclusion or removal. All are trying to answer the question: does predator control benefit game populations, or is it a waste of time and money?
COYOTES AND FAWN SURVIVAL
In the past few years, a number of studies have tackled this issue. The first of these studies was focused on the impacts of coyote removal on white-tailed deer fawn recruitment in central Georgia (Gulsby et al. 2015). The study took place at two wildlife management areas and tracked fawn survival and estimated coyote abundance for three years, removing coyotes during the second and third years.
In the past few years, a number of studies have tackled this issue. The first of these studies was focused on the impacts of coyote removal on white-tailed deer fawn recruitment in central Georgia (Gulsby et al. 2015). The study took place at two wildlife management areas and tracked fawn survival and estimated coyote abundance for three years, removing coyotes during the second and third years.
The researchers found that the removal of coyotes elicited an increase in fawn recruitment at only one of the two wildlife management areas. Additionally, where fawn recruitment did increase, recruitment dipped following the second year of removals. This suggests that while the initial fawn increase may have been related to coyote removal, other environmental factors or non-resident coyotes may also be impacting fawn recruitment.
Another study in Georgia took a different approach to limiting the impacts of predators. Mike Conner of the Joseph W. Jones Ecological Research Center and his colleagues constructed four small, fenced exclosures that were tall enough to exclude coyotes, foxes, and bobcats, but short enough for deer to jump (approximately 4 feet tall; Conner et al. 2016). Using trail cameras and thousands of images over two years, the researchers were able to predict fawn recruitment inside and outside of the predator exclosures.
Their prediction stated that fawn recruitment was almost double inside the fences. These findings suggest that providing small areas where does can give birth without risk of predation will increase recruitment. Fawns are the most susceptible to predation during the first few weeks after birth, and by the time the fawns could jump the fencing to leave the exclosures, they would be fast enough to evade any predators.
WOLVES AND CARIBOU
Related work in Canada investigated the impacts of wolf management on the declining woodland caribou population in Alberta (Hervieux et al. 2014). The group estimated adult female caribou survival and the ratio of calves to cows (female caribou) at two different locations in western Alberta. From 2005 to 2012, the researchers removed a total of 841 wolves from the two areas. The removal resulted in a 4.6 percent growth rate in the population in one of the two sites; however, the second site experienced at 4.7 percent decline. Much like the coyote removal research by Gulsby et al. (2015), researchers came to the conclusion that additional environmental factors, such as habitat quality and abundance, were also influencing the prey population.
Related work in Canada investigated the impacts of wolf management on the declining woodland caribou population in Alberta (Hervieux et al. 2014). The group estimated adult female caribou survival and the ratio of calves to cows (female caribou) at two different locations in western Alberta. From 2005 to 2012, the researchers removed a total of 841 wolves from the two areas. The removal resulted in a 4.6 percent growth rate in the population in one of the two sites; however, the second site experienced at 4.7 percent decline. Much like the coyote removal research by Gulsby et al. (2015), researchers came to the conclusion that additional environmental factors, such as habitat quality and abundance, were also influencing the prey population.
It’s important to remember that every ecological interaction is different. When predators are negatively impacting prey populations, predator exclusion may be an alternative option to predator removal. However, in some cases, prey decline may not be a result of predators alone. Habitat quality and other variables (drought, human-conflict, hunting pressure) can be influencing the population in conjunction with predators, so unaided removals may not provide the desired results.
Bottom line: Before blaming predators for ungulate-harvest woes, contact your regional wildlife agency and see what research or surveys they have conducted. If predation is an issue in your region, be sure to always follow any harvest regulations regarding predators, and work together with agencies to make sure the proper steps are taken to aid prey populations.
Sources
Conner, M. L., M. J. Cherry, B. T. Rutledge, C. H. Killmaster, G. Morris and L. L. Smith. 2016.Predator exclusion as a management option for increasing white-tailed deer recruitment. The Journal of Wildlife Management 80:162-170. DOI: 10.1002/jwmg.999
Gulsby, W. D., C. H. Killmaster, J. W. Bowers, B. N. Sacks, M. J. Statham and K. V. Miller. 2015.White-tailed deer fawn recruitment before and after experimental coyote removals in central Georgia. Wildlife Society Bulletin 39:248-255. DOI: 10.1002/wsb.534
Hervieux, D., M. Hebblewhite, D. Stepnisky, M. Bacon and S. Boutin. 2014. Managing wolves (Canis Lupis) to recover threatened woodland caribou (Rangifer tarandus caribou) in Alberta. Canadian Journal of Zoology 92:1029-1037. DIO:10.1139/cjz-2014-0142
Coyote Photograph via MSU Deer Lab
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The resumption of wolf-hunts in Idaho, Montana and Wyoming illustrates why citizens must continue to oppose such unnecessary and senseless slaughters.
The wolf-hunts are predicated upon morally corrupt and inaccurate assumptions about wolf behavior and impacts that are not supported by recent scientific research. State wildlife agencies pander to the lowest common denominator in the hunting community—men who need to bolster their own self esteem and release misdirected anger by killing.
Wolf-hunts, as Montana Fish and Game Commission Chairman Bob Ream noted at a public hearing, are in part to relieve hunters’ frustrations—frustration based on inaccurate information, flawed assumptions, and just plain old myths and fears about predators and their role in the world.
Maybe relieving hunter frustration is a good enough justification for wolf-hunts to many people. However, in my view permitting hunts to go forward without even registering opposition is to acquiesce to ignorance, hatred, and the worst in human motivations. Thankfully a few environmental groups, most notably the Center for Biodiversity, Wildearth Guardians, Friends of the Clearwater, Alliance for Wild Rockies and Western Watersheds had the courage and gumption to stand up to ignorance and hatred.
All of the usual justifications given for wolf-hunts are spurious at best. For instance, one rationale given for hunting wolves is to reduce their presumed effects on big game populations. Yet in all three states, elk and deer populations are at or exceed population objectives for most hunting units.
For instance in Wyoming, one of the most vehement anti wolf states in the West, the 2010 elk population was 21,200 animals over state-wide objectives, and this did not include data for six herds, suggesting that elk populations are likely higher. Of the state’s elk herds most were at or above objectives and only 6 percent were below objectives. Similar data are found for Idaho and Montana elk herds as well.
However, you would not know that from the “howls” of hunters who characterize the elk populations as suffering from a wolf induced Armageddon. And Fish and Game departments are loath to counter the false accusations from hunters that wolves are somehow “destroying” hunting throughout the Rockies.
Experience in other parts of the country where wolves have been part of the landscape longer suggests that in the long term, wolves – while they may reduce prey populations in certain locales – generally do not reduce hunting opportunities across a state or region. Despite the fact that there more than double the number of wolves in Minnesota (3000+) as in the entire Rocky Mountain region, Minnesota hunters experienced the highest deer kills ever in recent years, with Minnesota deer hunters killing over 250,000 white-tailed deer during each of those hunting seasons – an approximate five-fold increase in hunter deer take since wolves were listed under the ESA in 1978.
Another claim made by wolf-hunt proponents is that hunting will reduce “conflicts” with livestock owners. Again this assertion is taken as a matter of faith without really looking into the veracity of it. Given the hysteria generated by the livestock industry one might think that the entire western livestock operations were in jeopardy from wolf predation. However, the number of livestock killed annually by wolves is pitifully small, especially by comparison to losses from other more mundane sources like poison plants, lightning and even domestic dogs.
For instance, the FWS reported that 75 cattle and 148 sheep were killed in Idaho during 2010. In Montana the same year 84cattle and 64 sheep were verified as killed by wolves. While any loss may represent a significant financial blow to individual ranchers, the livestock industry as a whole is hardly threatened by wolf predation. And it hardly warrants the exaggerated psychotic response by Congress, state legislators and state wildlife agencies.
In light of the fact that most losses are avoidable by implementation of simple measures of that reduce predator opportunity, persecution of predators like wolves is even more morally suspect. Rapid removal of dead carcasses from rangelands, corralling animals at night, electric fencing, and the use of herders, among other measures, are proven to significantly reduce predator losses—up to 90% in some studies. This suggests that ranchers have the capacity (if not the willingness) to basically make wolf losses a non-issue.
However, since ranchers have traditionally been successful in externalizing many of their costs on to the land and taxpayers, including what should be their responsibility to reduce predator conflicts, I do not expect to see these kinds of measures enacted by the livestock industry any time soon, if ever. Ranchers are so used to being coddled they have no motivation or incentives to change their practices in order to reduce predator losses. Why should they change animal husbandry practices when they can get the big bad government that they like to despise and disparage to come in and kill predators for them for free and even get environmental groups like Defenders of Wildlife to support paying for predator losses that are entirely avoidable?
But beyond those figures, wolf-hunting ignores a growing body of research that suggests that indiscriminate killing—which hunting is—actually exacerbates livestock/predator conflicts. The mantra of pro wolf-hunting community is that wolves should be “managed” like “other” wildlife. This ignores the findings that suggest that predators are not like other wildlife. They are behaviorally different from say elk and deer. Random killing of predators including bears, mountain lions and wolves creates social chaos that destabilizes predator social structure. Hunting of wolves can skew wolf populations towards younger animals. Younger animals are less skillful hunters. As a consequence, they will be more inclined to kill livestock. Destabilized and small wolf packs also have more difficulty in holding territories and even defending their kills from scavengers and other predators which in end means they are more likely to kill new prey animal.
As a result of these behavioral consequences, persecution of predators through hunting has a self fulfilling feedback mechanism whereby hunters kill more predators, which in turn leads to greater social chaos, and more livestock kills, and results in more demands for hunting as the presumed solution.
Today predator management by so called “professional” wildlife agencies is much more like the old time medical profession where sick people were bled. If they didn’t get better immediately, more blood was let. Finally if the patient died, it was because not enough blood was released from the body. The same illogical reasoning dominates predator management across the country. If killing predators doesn’t cause livestock losses to go down and/or game herds to rise, it must be because we haven’t killed enough predators yet.
Furthermore, most hunting occurs on larger blocks of public lands and most wolves as well as other predators killed by hunters have no relationship to the animals that may be killing livestock on private ranches or taking someone’s pet poodle from the back yard. A number of studies of various predators from cougars to bears show no relationship between hunter kills and a significant reduction in the actual animals considered to be problematic.
Again I hasten to add that most “problematic predators” are created a result of problem behavior by humans—for instance leaving animal carcasses out on the range or failure to keep garbage from bears, etc. and humans are supposed to be the more intelligent species—though if one were to observe predator management across the country it would be easy to doubt such presumptions.
Finally, wolf-hunting ignores yet another recent and growing body of scientific evidence that suggests that top predators have many top down ecological influences upon the landscape and other wildlife. The presence of wolves, for instance, can reduce deer and elk numbers in some places for some time period. But rather than viewing this as a negative as most hunters presume, reduction of prey species like elk can have many positive ecological influences. A reduction of elk herbivory on riparian vegetation can produce more song bird habitat. Wolves can reduce coyote predation on snowshoe hare thus competition for food by lynx, perhaps increasing survival for this endangered species. Wolves have been shown to increase the presence of voles and mice near their dens—a boon for some birds of prey like hawks. These and many other positive effects on the environment are ignored by wolf-hunt proponents and unfortunately by state wildlife management agencies as well who continue to advocate and/or at least not effectively counter old fallacies about predators.
Most state agencies operate under the assumption that production of elk and deer for hunters to shoot should have priority in wildlife management decisions. All state wildlife agencies are by law supposed to manage wildlife as a public trust for all citizens. Yet few challenge the common assumption that elk and deer exist merely for the pleasure of hunters to shoot.
I have no doubt that for many pro wolf-hunt supporters’ predators represent all that is wrong with the world. Declining job prospects, declining economic vitality of their rural communities, changes in social structures and challenges to long-held beliefs are exemplified by the wolf. Killing wolves is symbolic of destroying all those other things that are bad in the world for which they have no control. They vent this misdirected anger on wolves– that gives them the illusion that they can control something.
Nevertheless, making wolves and other predators scapegoats for the personal failures of individuals or the collective failures of society is not fair to wolves or individuals either. The premises upon which western wolf-hunts are based either are the result of inaccurate assumptions about wolf impacts or morally corrupt justifications like relieving hunter anger and frustrations over how their worlds are falling apart.
I applaud the few environmental groups that had the courage to stand up for wolves, and to challenge the old guard that currently controls our collective wildlife heritage. More of us need to stand up against persecution of wildlife to appease the frustrations of disenfranchised rural residents. It is time to have wildlife management based on science, and ecological integrity, not based upon relieving hunter frustrations over the disintegrating state of their world. And lastly we need a new ethnics and relationship to wildlife that goes beyond a simple utilitarian view of whether any particular species benefits or harms human in real and/or imaginary ways.
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