Category: Save the Wolves

In the snowy woods of the western Upper Peninsula, wildlife researchers are learning a thing or two about deer survival: what preys on adult whitetails and fawns — and what else contributes to their deaths. Some in the hunting community presume the answer is wolves. Many know harsh winters take a toll. Both are true, according to recent research, but a lot depends on other factors, such as the availability of young forests and food, predator density, and what other prey are available. The study, started in 2009 by Mississippi State University and the Michigan Department of Natural Resources, has turned up some surprises. “We’ve been surprised by a few things in Phase I (low-snow study),” notes Dean Beyer, a researcher with the DNR. “We learned that adult does were avoiding core wolf areas and that coyotes were avoiding them, too. That put coyotes and does in the same area, which probably resulted in a greater mortality by coyotes. And we were all surprised by the rate at which bobcats killed fawns. The rate is much higher than other species.” The study, known as The Predator Prey Project, is a three-phase endeavor that examines ecological interactions in low-snow, moderate-snow and deep-snow regions of the western U.P. The answers are being derived by tracking deer fitted with radio-telemetry collars and predators fitted with GPS collars. The low-snow work wrapped up in 2011. The moderate snow work is slated to finish this year. Then three years of deep-snow work will begin, provided funding can be found. Two Phase I findings are particularly interesting. “Predation was the leading cause of mortality, 3.5 times more hazardous than human-caused mortality sources,” the preliminary report states, along with “Overall, coyotes were the leading cause of adult female mortality, followed by wolves.” Predation by black bears was infrequent and considered “opportunistic,” and wolves were not considered important predators for fawns. Beyer suggests the proximity of coyotes and deer boosted those mortality numbers. Wolves in the low-snow zone were often feeding at livestock carcass dumps. “Coyotes in Phase I were the biggest and most important predator of fawns and adult does,” Beyer said. “In Phase II (the moderate snow zone) coyotes cause the most total mortality of fawns, but when we look at adult deer, wolves jump up to No. 1; I think because they don’t have the livestock carcass dumps.” The winter season also has an impact, according to the report: “Adult female mortality was greatest during winter (44 percent of those deaths), followed by spring/summer (37 percent), and fall (19 percent).” Winter severity, which can hinder a deer’s ability to move around and feed, in turn can affect fawn size at birth. A 2.-pound reduction in a newborn fawn’s weight can increase mortality by 11 percent, the research shows. “Phase II has been interesting because we have had some very severe winter conditions,” Beyer said. “A couple of things jumped out. In 2013, (adult) doe survival was 58 percent, which is on the low end of things. In 2014, when we had even more severe weather, doe survival was 38 percent — some of the lowest survival rates I’ve seen in the literature. Those conditions stressed the does, and the fawns were born in poor condition. “We pretty much lost the fawn crop in 2013 and had fairly low fawn survival in 2014, when 11 percent of the fawns survived.” For those who remain certain that Michigan wolves will decimate the deer herd, Beyer suggests it is unlikely. The two species, he says, have evolved together, and other factors influence outcomes. Habitat and predator densities are just two. Then there are predator’s energy needs. Coyotes, for instance, are more likely to kill fawns while wolves are more likely to kill adult does. They need more meat/fuel to sustain themselves. “What we know from the scientific literature is there are only two reports where wolves are believed to have contributed to a substantial reduction of deer … winter weather is still the driving factor, even in the low-snow zone,” Beyer said.

There are still a couple wolves alive on Isle Royale! Researchers working on the Wolves and Moose of Isle Royale project found tracks of two wolves frozen in the slush of Lake Eva. They had spent time during a two-day thaw nosing around an active beaver pond. For over 50 years Project researchers have been observing and learning about the predator and prey dynamics between wolves and moose on Isle Royale National Park. Sadly, wolves have shown a 90% decline since 2009. For decades the wolf population kept itself healthy by occasional immigrants from the mainland. But with warming temperatures the frequency of ice bridge formation has dropped dramatically. As of last fall only 3 wolves remained. Experts say those animals are inbred and weak and without intervention, the island’s native population wolf may go extinct. So while it is reassuring that at least 2 wolves are still roaming the island, scientists leading the project insist that importing wolves from the mainland is the population’s only chance of recovery.

Predator and Prey What the wolf lacks in size, power and weapons it makes up for with collaboration and intelligence. Smaller and less powerful than mountain lions, for example, wolves work together to take down prey much larger than an individual wolf; prey that may otherwise elude them. While individual wolves have been able to subdue large prey animals, their advantage is in collaborating with their pack. Wolves are opportunists. They test their prey, sensing any weakness or vulnerability through visual cues and even through hearing and scent. Contrary to ambush predators that rely on the element of surprise and a short and intense burst of energy to secure their prey, wolves are endurance or coursing predators. They chase their prey, often over longer distances, sometimes even a few miles, in order to find the right animal or opportunity. On the hunt, wolves work together with certain individuals typically carrying out their specific role in the hunt, often based on age, gender and social standing. While wolves will eat hares and other small prey, their preferred targets are ungulates, large hoofed animals such as deer and elk. Individual packs will specialize in hunting specific prey species. While most often that is elk, caribou, deer and moose, it can also be bison, muskoxen, Dall sheep or even salmon. It is not uncommon for wolves to be injured or even killed during the hunt by being kicked by a hoof or gored by an antler. Most often the prey they select is in some way weaker and/or more vulnerable than the other animals in the herd. They may be injured, sick, old, very young or genetically inferior. But even healthier animals can at times find themselves in a vulnerable position. Over time this process allows the most capable prey animals to survive and pass on their genes and it helps to limit the spread of diseases within the herd. This is an ancient evolutionary success story shared by both predator and prey. On the Hunt It is during a hunt where co-operation between wolves within a pack is most apparent. A wolf pack may trail a herd of elk, caribou or other large prey for days before making its move. During this time, they are already hunting, assessing the herd, looking for an animal that displays any sign of weakness, and this is just the beginning. Wolves must also factor in other conditions that will affect the hunt; weather and terrain can tip the scales in favor of predator or prey. For example, a wide-open plain favors the ungulates, who, if full-grown and healthy, can outrun the fastest wolf. On the other hand, crusty snow or ice favors the wolves whose wide round paws have evolved to perform like snowshoes and carry them effortlessly over the surface. An experienced wolf is well aware that hoofed animals break through the crust and can become bogged down in deep snow. Wolves have learned to use these conditions to their advantage. The late wolf biologist, Dr. Gordon Heber speaks of a particular pack in Alaska that he has observed following a herd of caribou on a narrow packed trail through deep snow. The wolves know that their mere presence, following close behind, will eventually panic the caribou. When the rearmost caribou spooks, leaving the hard trail and attempting to run to the middle of the herd, it founders in the snowdrifts. When that happens it is all over. In warm weather, this same pack of wolves changes its tactics, herding the caribou into a dry riverbed where many of the ungulates stumble on the round stones. A wolf pack therefore weighs many different factors when selecting its target and, as circumstances change during the hunt the target may change as well. Initially they may be pursuing a calf, but if a big healthy bull stumbles unexpectedly, they all know to go after the bigger meal. Conversely, if too many factors seem to favor the prey, they may choose to wait. Sometimes it is better to stay a bit hungry until the odds improve rather than expend precious energy on a fruitless chase. Other observers of wolves have reported that often fewer than half of wolves on a hunt are actually involved with physically bringing down the prey. The youngest wolves frequently do nothing more than observe and learn from the sidelines. Each of the other pack members contributes according to its particular experience and ability. Speedy, lightly built females often take on herding roles, darting back and forth in front of prey, causing confusion and preventing escape. Slower but more powerful males are able to take down a large animal more aggressively and quickly. Some of the wolf’s bad reputation stems from the apparent mob scene that ensues when the prey begins to falter. Wolves are not equipped to dispatch their victims quickly; prey usually die of shock, muscle damage or blood loss. If it can, one of the stronger wolves will seize the prey by the nose and hold on tight, helping to bring about a more expeditious end, but the animal can still take many minutes before it succumbs. Equipped only with feet for running and jaws for biting, wolves make the best of their limitations. A wolf pack’s ferocity and apparent brutality is really a defensive measure. It is not rare for a wolf to be seriously injured by flailing hooves and slashing antlers. A well-placed kick could break a wolf’s jaw, rendering it unable to feed itself. It is much safer to harass the prey and let it tire out before moving in close. Far from being a mob scene, a hunt is a masterfully coordinated group effort, well deserving of our admiration. Although the alpha male is usually in the thick of the hunt, it would be an exaggeration to say that he is leading it. The alpha may select the animal to be pursued, or he may chose to break off the hunt if it is going poorly.…