New research shows that by reducing populations and thinning out weak and sick animals, wolves are helping create more resilient elk herds. All that effort burns calories, weakening them heading into winter. As adaptable, intelligent predators, wolves have learned to recognize these conditions, and they would rather kill an undernourished pound bull versus a pound cow.
So by targeting bulls during years of scarce food, they give the cows a chance to reproduce, thus keeping the population afloat. For instance, elk herds that maintain consistent numbers, rather than yo-yoing up and down, can better withstand more frequent droughts—one impact of climate change that is already occurring in the region.
The findings in Yellowstone are also relevant, he adds, as Coloradans vote in November whether to reintroduce wolves to their state, home to about , elk—the largest number in the U. For their study, Wilmers, Smith, and colleagues analyzed more than a thousand dead elk in Yellowstone —located in the states of Wyoming, Montana, and Idaho—over 20 years.
The team then used satellite data to derive how much plant life was available for elk to eat each year, an amount dependent on snowmelt and rainfall. This is especially useful for managing and conserving wolves, which are still rebuilding their numbers after over a century of persecution. Before the s, Yellowstone predators such as grizzly bears, black bears, wolves, and mountain lions thrived alongside robust populations of American bison, elk, mule deer, pronghorn, and bighorn sheep.
But a coordinated campaign by the federal government exterminated almost all those predators, and bison, from the area. The last known Yellowstone wolf pack was killed in , and the canines were also wiped out in most of their historic range in much of the lower 48, hanging on in a few populations around the Great Lakes. Read more about the history of Yellowstone National Park. With the wolves gone, and bears and lions greatly diminished, elk populations skyrocketed.
Between and , the U. When the park stopped killing elk in , numbers shot up again from about 5, to close to 20, Snakes and Lizards. Sonoran Pronghorn. Wild Places. California's Central Valley. Coasts and Intertidal Zones. Deciduous Forests. Great Plains. Greater Everglades. Northwest Florida. Rocky Mountains. Sagebrush Sea. Sky Islands. Southern Appalachians. Temperate Rainforest. Texas Hill Country.
Wetlands and Rivers. Our Work. Conserving Imperiled Species. Advocating for International Species. Protecting Habitat. Promoting Coexistence. Defending Conservation Laws. Innovating for Wildlife Conservation. Combating Climate Change. Fighting Invasive Species. Speaking for Wildlife. Where We Work. Wildlife Nation. Take Action. Add Your Voice. Attend an Event. Check Out the Activist Toolkit. Advocate in Your State. Wolves enhance the health of prey species by controlling their populations and hunting the weak, old and immature.
In order to identify these weaker individuals, they will charge into a herd and see who begins to fall behind.
They will then position themselves in a way that separates the target out from the rest of the herd. An average pack kills an elk approximately every two to three days, but wolves can go for weeks without eating when prey is scarce. Not knowing when their next meal might come, wolves can eat more than 20 pounds of meat in a single meal. Packs break into smaller groups during the summer, when prey is more bountiful, and the mating season is forthcoming.
Wolves alone or in pairs will hunt smaller prey such as beavers, rabbits and rodents, in addition to scavenging. They may also eat livestock when it is available, leading to conflicts with ranchers. As breeding season gets close, the alpha male and female will increase the amount of time they spend together, and decrease the amount of physical space between themselves when resting and sleeping.
After mating, the female creates a den in which to raise her young. This is a moment of great responsibility for the alpha female, for the pack will need to hunt in that general area until the pups are old enough to travel. If she chooses a denning site that is far from prey, the extra distance required for hunting forays will put additional strain on the entire pack. The den is often dug underground, with a to foot entrance leading to an elevated platform to avoid flooding , where the pups will be born and remain for several weeks.
Dens are also constructed under cliffs, under fallen trees and in caves. The gestation period for gray wolves lasts between 60 and 63 days, and the average litter size in Yellowstone is 4. Once born, the pups are cared for by all of the adult members of the pack. YOUNG Born blind and deaf and weighing only 1 pound, wolf pups are completely dependent on their mother for warmth and sustenance. However, at 10 to 15 days of age, the pups have grown significantly, weighing 4 pounds, and their blue eyes open for the first time.
These youngsters are only able to crawl, as their back legs are not yet fully functional. Five to 10 days later, the pups can stand and walk. Sometime between the 20th and the 77th day, the pups will leave the den for the first time under the watchful eye of their mother and learn to play fight, which determines the ultimate pup dominance hierarchy. By six months of age, healthy pups can weigh 60 pounds and are able to travel and hunt with the pack.
Most pups will stay with the pack for at least one to four years, and some stay in their original pack for life. The oldest wild wolves might reach an age of 12 or 13 years, but this is rare.
Highlighting the value of protection in a national park, 77 percent of wolf mortality inside the park is from natural causes, and outside the park in the Greater Yellowstone Ecosystem, 77 percent of deaths are human caused. Repeater Layout : vertical-2up. New Itinerary! Photo departures available. New Trip! Know Before You Go. Get Weekly Updates Our weekly eNewsletter highlights new adventures, exclusive offers, webinars, nature news, travel ideas, photography tips and more.
Sign Up for Emails. Our weekly eNewsletter highlights new adventures, exclusive offers, webinars, nature news, travel ideas, photography tips and more. And the carrion they generate benefit many species, from beetles to birds to wolverines. Unfortunately, it is quite the opposite.
While hunting is not allowed in Yellowstone, these three states allow trophy hunting and trapping elsewhere on their lands and in the areas bordering the park. As a result, even beloved and well-known Yellowstone wolves have found themselves in the crosshairs after stepping over the invisible park boundary. In the Fall of , Spitfire , also known as F, who was descended from the first group of wolves reintroduced into Yellowstone, was killed just across the boundary by a trophy hunter in Montana.
The state was forced to drastically reduce its quota the following year. Such indiscriminate killing substantially diminishes the ability of millions of people to see these iconic carnivores in the wild. One study found that wolf sightings in Yellowstone decrease significantly after park wolves are killed in areas adjacent to the park; other studies have reported similar findings.
Montana has shown some signs of recognizing the problem, and is now poised to take a small step in the right direction. Recently, the Montana Fish and Wildlife Commission proposed reducing the quota of wolves in two management areas bordering Yellowstone.
We support any reduction in the number of wolves killed, but just limiting the killing is not enough. What we truly need is a buffer zone around the park to protect wolves like Spitfire who are incapable of seeing an invisible line and end up crossing it. We have a long history of advocating for wolves in Yellowstone and in other locations. Twenty-five years ago, when those first 14 wolves arrived at Yellowstone from Canada, our own Dave Pauli, now senior adviser for response and policy at the HSUS, was on the ground, rallying public support for the wolves and helping ensure the survival of the newly introduced animals.
Recently, we celebrated news of a recent sighting of a pack of wolves in Colorado, marking the first time in recent history that multiple wolves have been travelling together in the state — a positive outcome, no doubt, of the return of the Yellowstone wolves.
0コメント