Yellowstone Association naturalist. We had stopped to look at three moose, who promptly disappeared into a willow thicket. Then a dipper caught our eye. The slate gray, aquatic songbird dove through the inky waters of the Lamar River, then bobbed onto an ice shelf with an insect in its beak. Two eagles presided regally over the scene from their high perches in gnarled trees.
The second coyote we saw was alive – standing on the far bank of the river, its bushy tail and slight build silhouetted against the snow. These song dogs (a nickname earned through their frequent, yipping howls) have had an interesting history in Yellowstone National Park, and across the country. Although they were persecuted – trapped, poisoned, shot – just like most western predators, they were able to survive and multiply, expanding their range into Alaska, Central America, east to Nova Scotia, and into farmland, cities, and suburbs.
Coyotes' success is partly due to their adaptability. Their wide-ranging diet includes mice, voles, rabbits, elk, pronghorns, and even carrion, insects, and trash. Having escaped the predator elimination efforts, coyotes were handed a habitat free of their main predators – wolves. By the 1920's, wolves were extirpated from most of the United States, including Yellowstone. Only Alaska and northern Minnesota retained a continuous population of Canis lupus.
In the absence of wolves, coyotes changed their behavior to fill the niche of an apex predator. By living in larger packs than usual – up to seven coyotes in a family group – with the same alpha-led structure as wolves, coyotes could take down larger prey. Their population increased more.
Almost exactly twenty years after the wolves' return to Yellowstone, Carolyn pointed out a patch of dense mixed forest on a side slope in the Lamar Valley, where the remains of their 1995 release pen still stands. The reintroduction of wolves into the Yellowstone ecosystem was not a lightly-made decision or an easy task. It was not without controversy, and certainly, no one asked the coyotes.
In the first year of the wolves' return, they killed at least 12 coyotes in the Lamar Valley. Harassment continued, and the coyote population on the northern range (where wolves were reintroduced) decreased by 50 percent. Not only were the wolves and coyotes competing for some of the same food sources and territories, but wolves actively attacked coyotes that crossed their paths, and destroyed dozens of coyote pups near the dens.
Unfailing in their adaptability, coyotes quickly relearned how to live in a wolf-dominated landscape. With a decrease in pack size, increase in wariness, and return to smaller prey, their numbers may once again be on the increase.
Wolves impact much more than just coyotes, though. According to the Park Service, wolves' predation on elk calves and adults has contributed to the herd size being cut by over 50 percent – to a much more manageable size for the habitat. The elk's behavior changed, too, since they were easy targets in the brushy willow valleys where they liked to browse. This allowed willow and aspen saplings to survive, beavers to increase, and overall habitat to improve. In addition, wolf-killed elk carcasses feed an incredible array of scavengers. Ravens, magpies, bald eagles, and golden eagles have all benefitted since the wolves' return. Grizzly bears often usurp wolf kills, too.
While that fox came up empty-pawed in the meadow, it has profited substantially from the return of wolves. Just as wolves compete with and kill coyotes, coyotes compete with and kill foxes. Wolves' and foxes' diets barely overlap, though, and they are much more tolerant of each other. So as the wolves increase and coyotes decrease, foxes increase, too.
While the fox pounced again (and again), the snowcoach rumbled on. Past wooly bison, rare plants, steaming valleys, obsidian-flecked hillsides, river gorges, waterfalls, and countless breathtaking views, we drove deeper into the park. As dusk crept in, I began to go glassy-eyed with fatigue and the overwhelming splendor of the day. Then, with an almost audible click, my eyes locked with his. The wolf stood ankle deep in the Fire Hole River. He shook water from his coat in a flash of movement that woke me up. "Stop! Wolf!" I cried out, startling the whole crew out of our reveries.
From the cover of our snowcoach, we watched him feed on the bony carcass of an elk, pull chucks of meat out of the river, and pee on the snow. Rapt in his wildness, astounded by our luck, we watched the light fade on our "three dog day." Just another taste of the magic of Yellowstone.
Emily Stone is a Naturalist/Educator at the Cable Natural History Museum. Visit http://www.cablemuseum.org to learn more about exhibits and programs at the museum. For more from Emily Stone, visit her blog at http://cablemuseumnaturalconnections.blogspot.com/.
About the Cable Natural History Museum:
For over 45 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI, at 13470 County Highway M. The current exhibit, "Deer Camp: A Natural and Cultural History of White-tailed Deer," opened in May 2013 and will remain open until April 2014.