When settlement in the late 1800s at the south end of the valley eliminated about two-thirds of their winter range, as many as 500 elk sometimes ended up on the streets of Jackson on frigid nights. Winter starvation and poaching pressures took many elk.
The fur trade decimated beaver populations. But what of moose, deer, and bighorn? Moose and mule deer probably benefited from white settlement. Moose increased because of the suppression of fire, which permitted the increase of sub-alpine fir, a winter food source. Moose graze but little grass, mostly browsing coarser plants. Likewise mule deer. Livestock overgrazing hindered elk but favored moose and mule deer. The latter evidently usurped bighorn wintering range, reducing the sheep population. Wolves were extirpated and grizzly bears nearly so. That favored—within range support limits—every four-footed vegetarian not beset with other insurmountable problems.
Grizzly bears roam only the northern part of the park. Predation on large mammals must be carried out by seldom seen black bears, rare mountain lions, and coyotes, who largely feed on rodents. Red foxes (rare here), lynxes, and bobcats are crafty and formidable, but at best threaten only the young of large mammals. Formidable predators of a smaller scale are the many members of the weasel family, including two weasels, the badger, pine marten, wolverine and fisher (very rare here), and mink. The prey of these creatures includes many of the more familiar small mammals, such as shrews, hares, chipmunks and golden-mantled ground squirrels, Uinta ground squirrels, red and flying squirrels, mice, pocket gophers, woodrats, voles, and muskrats, and also small birds, bird eggs, reptiles, and amphibians. Porcupines and beavers are both large rodents and both feed on bark, but their defenses differ. Beavers escape to their snug lodge protected by the surrounding water, while porcupines are protected by quills. But porcupines sometimes fall prey to fishers and maybe smaller cats and other critters able to get at their unprotected faces and bellies.
The vigorous, brief blooms of alpine plants edge a high mountain meadow, with only the tips of peaks as a backdrop.
Bird watchers are content here just to see the rare trumpeter swan—on the Elk Refuge, or at Christian and Hedrick Ponds. Other large birds include bald eagles, ospreys, sandhill cranes, Canada geese, and great blue herons. The water ouzel (dipper) walks underwater in fast current, a marvel to behold. Bold and brassy are the crafty magpies, who won’t hesitate to let you know if you annoy them. More than 100 species of birds have been identified in the park.
Four major natural communities provide a way of understanding the park’s wildlife patterns. The water communities include lakes, ponds, rivers, and streams. The sage and grassland community is the most extensive and most often overlooked. The forest community appears randomly distributed, but soil moisture properties, the direction it faces, elevation, and weather patterns influence where trees grow. Blue spruce and cottonwood thrive along valley streams. Aspen, Douglas-fir, and lodgepole pine inhabit the valley and lower slopes. Sub-alpine fir, Engelmann spruce, and limber pine stand on mountainsides and in canyons. The edges where communities meet are richest in wildlife. The alpine community crowning the highcountry shares the least characteristics and organisms with the other three communities.
Water communities call to mind perhaps the trout and beaver (see pages [48] and following), and lakes, ponds, streams, and rivers interrupt or dot the other three communities. In winter moose inhabit the river flats to browse the cottonwoods and willows.
The pronghorn and sage grouse characterize the wide open sage and grassland community, whose purpose otherwise seems simply to provide the Teton Range a foreground. This world is alive with small birds feeding on masses of insects and spiders. These songbirds, along with gophers, mice, and snakes, provide the diet for weasels, hawks, and ravens. The sage grouse depends largely on the evergreen sagebrush for food. The pronghorns depend on it part-time, being unable to subsist on grasses alone. This is North America’s fastest mammal, able to run at more than 45 miles per hour. For added security it boasts oversize lungs and windpipe, and the largest eyes by body weight of any mammal. Faster yet is the prairie falcon that hunts these flats, streaking out of the sky at speeds up to 200 miles per hour.
An aspen grove of only 27 trunks may shelter more than 12 pairs of birds—house wrens, mountain bluebirds, swallows, and woodpeckers. It may also shelter an understory of young spruce and fir that could one day replace it. Deer and elk wander out of the forest to browse the aspen, which can produce more than 2.5 tons dry weight of vegetation per acre. Ironically, aspen have suffered somewhat in the park for lack of forest fires. It turns out that fire suppression suppresses aspens, which recover burned areas quickly. In respect of natural processes, the park now practices wildfire management instead of complete suppression, except where human life and private property might be threatened.