Great Sand Dunes
From Pikas To Pronghorns
Introduction to Great Sand Dunes Mammals
National Park Service U.S. Department of the Interior Great Sand Dunes National Park and Preserve
Rocky Mountain elk walking on sand dunes? Beavers on wetland shores beside desert kangaroo rats? Bighorn sheep grazing on chilly alpine tundra one week, then on warm dunes the next? Nowhere else in North America do alpine tundra, tall forests of evergreen and aspen, massive desert dunes, spacious grasslands, and verdant wetlands meet so dramatically in one park of unparalleled natural diversity. The recently expanded national park and preserve protects the entire geological and biological system of the Great Sand Dunes, from alpine snowfields where the park’s streams begin their journey, to wetlands west of the dunes where these waters collect into lush pools teeming with life. On that journey from snowfields to sand dunes, these streams pass by a stunning variety of mammals pikas to pronghorns, and bighorn sheep to badgers. Medano and Sand Creeks start in the spring as snowfields on 13,000’ peaks, melting into alpine lakes situated at timberline. Bighorn sheep and Rocky Mountain elk graze on grassy, treeless slopes near the frigid waters. Snow Buttercups push through warming snowfields. Pikas (small, short-eared members of the rabbit family) and marmots (resembling a large woodchuck with a heavy fur coat) search among the rock and snow for new green shoots. They resist the cold with round bodies, short ears and limbs, and heavy fur. Even in spring and summer, the air temperature on the tundra rarely rises above 50 degrees F (10 C), and usually drops below freezing at night.
Antilocapra americana
Pronghorn
Alpine Tundra
Pika
Ochotono princeps
Bighorn Sheep
Ovis canadensis
Mammals adapt to the cold with thick fur and fat layers - just the opposite of what a mammal might wear in the dunes at the base of the mountains.
Marmot
Marmota flaviventris
Forest and Woodlands As the icy water cascades from the lakes,
Black Bear
Ursus americanus
it enters shady ancient forests of pine, spruce, and fir. Pine martens (large brown weasels) hunt squirrels in the trees. Along the streams’ edges, black bears capture cutthroat trout and dig up succulent roots, while beavers gnaw aspens for food and to strengthen their dams. In wet years, a plethora of wildflowers and grasses grows on the damp, sun-dappled forest floor - rich food for mule deer, snowshoe hares, and other herbivores. Mountain lions slowly slink forward through the trees before bursting into the air, claws spread to capture a meal for themselves and their cubs.
Predators such as the mountain lion, bear, bobcat, and marten are vital links in the forest and tundra ecosystems, preventing over-populations of prey species. This fragile balance can be destroyed by the elimination of a species or habitat. Larger predators especially require large areas of unbroken forest and tundra for their survival. Fortunately, the Sangre de Cristo Range is a large federally designated wilderness, containing extensive ancient subalpine and montane forest, as well as rugged alpine tundra and lakes. Bobcat Ponderosa, pinon pines, Lynx Rufus and juniper grow in fragrant stands on lower, more arid slopes. The black Abert’s squirrel, readily identifiable with large ear tufts, thrives here. From the forests, Medano and Sand Creeks suddenly emerge into the massive dunes, cutting the eastern and northern edges of the dunefield and recycling sand from east back to west. Aspens give way to cottonwoods along the waterways, providing shelter for colorful songbirds, while bobcats, foxes, and coyotes prowl the creeks.
Mountain Lion
Felis Concolor
Dunes
Ord’s Kangaroo Rat
Dipodomys ordii
In the high dunes, surface temperatures can fluctuate between 140 degrees F (60 C) on a summer afternoon to -20 degrees F (-28 C) on a winter night. Winds can whip the dunes into a sandblasting gale. Only one mammal can live its entire life in these extreme conditions: the gerbillike Kangaroo Rat. These hearty creatures can leap five feet in the air to At the western edge of the dunes, the visible streams begin to wane and disappear into the sand. The sand is now free again to blow eastward back into the dunefield, and recycling is complete. The high dunes give way to low dunes and grasslands. With no obstacles in their path, pronghorn can run at speeds of over 50 miles per hour (80 kph) across the wide open expanse. Badgers, weasels, prairie dogs, and black-tailed jackrabbits dig the earth to make homes beneath the sod. While some elk migrate to higher elevations in warmer months, there are thousands that remain in the sandy grasslands throughout the year. The stream water, seemingly gone, resurfaces as springs and wetlands among the grassy sandhills on the west side of Great Sand Dunes. Large shore birds call and feed among lush cattails and rushes, while amphibians snap at insects. Bison and elk wallow and cool off in permanent and seasonal pools of water. These oases of life surrounded by sandy desert have also occasionally been home to beavers, who have built lodges from willow bush Medano and Sand Creeks’ journeys through so many of North America’s ecosystems now take place within an area managed by the National Park Service, protected for all future generations to enjoy and study. At Great Sand Dunes
avoid various predators that venture into the dunes at night. They can also survive without drinking water: first, by storing their grasses and seeds in the moist subsurface sand; second, by metabolizing dry starch into moisture; and third, by having extremely efficient kidneys. Rather than excreting moisture, they pass a crystal.
Desert Grasslands
Bison were almost extinct a century ago, but through careful management have returned to grasslands throughout the West. Today The Nature Conservancy manages a herd of about 1000 bison on lands just west of the main dunefield.
Rocky Mountain Elk
Cervus elaphus
Bison
Bison bison
Wetlands
Water Shrew
Sorex palustris
branches. How they find the water across miles of desert remains a mystery. More common is the water shrew, a seven inch (16 cm) long insectivore that lives in burrows along streams and ponds. Its fur and feet have special hairs that trap air bubbles, enabling the shrew to dive to the bottom of a pond to retrieve an insect or crustacean, then bounce back to the surface like a cork.
National Park and Preserve, the opportunity to see wildlife from these starkly contrasting ecosystems - sometimes in a single view - is yet another reason why this unique park is nationally and internationally significant. The Main Dunefield On brightly moonlit nights, the dunes are a good place to see kangaroo rats scurrying on the sand collecting seeds. Often coyotes, bobcats, weasels, and other predators hunt them in the dark. Mosca Pass Trail This trail follows Mosca Creek up through pinon-juniper woodlands, aspen groves, grassy meadows, and spruce-fir forest. Weasels, pine martens, mountain lions, red foxes, and black bears live here, but are usually only seen if hiking quietly. Medano Pass Primitive Road Most Rocky Mountain species are found here, including bighorn sheep and beaver. Alpine Trails The Medano Lake Trail and the Sand Creek Lakes Trail offer access to alpine lakes and tundra, to view marmots, pika, and bighorn sheep.
Selected Places To Observe Mammals
Most wildlife is observed in early morning or at dusk. Binoculars are especially helpful, since wild mammals are normally afraid of humans. Please keep wildlife wild. Do not approach, feed, or shine lights on any wild animal. These activities threaten the well-being of both you and the animals - and they are illegal. Check with a park ranger for specific trail and access information. Highway 150/Park Entrance Road Especially in autumn, winter and spring, this primary route into the park provides an opportunity to see mule deer, elk, pronghorn, and prairie dogs. Nature Conservancy Lands Bison tours are offered year round on Nature Conservancy lands within the national park. Call 719-378-2356 ext.110 for prices and availability.
Also visit www.nps.gov/grsa for more information on Great Sand Dunes wildlife.
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