As with its neighbor, Canyonlands National Park, the landscape of Arches National Park conceals most of its wildlife from human visitors. That said, lizards are easily spotted, and mule deer at cool times of day can be spotted browsing the vegetation.
Well, hello there, my deers, Arches National Park / Rebecca Latson
Desert animals have a variety of adaptations for dealing with the temperature and moisture stresses present in Arches. Most desert animals are nocturnal, being most active at night. This can be an adaptation to both predation and hot summer daytime temperatures. Mostly nocturnal animals include kangaroo rats, woodrats (also called packrats), and most other small desert rodents, skunks, ringtails, foxes, bobcats, mountain lions, bats and owls.
Animals that are most active at dawn and dusk are called “crepuscular.” These times of day are cooler than mid-day. The half-dark makes prey animals less visible, yet visibility is good enough to locate food. Some animals are crepuscular mostly because their prey is crepuscular. Crepuscular animals include mule deer, coyotes, porcupines, desert cottontails, black-tailed jackrabbits, and many songbirds.
A few desert animals are primarily active during the day, or “diurnal.” These include rock squirrels, antelope squirrels, chipmunks, lizards, snakes, hawks, and eagles. Many animals have a temperature range in which they are active, so alter their active times of day depending on the season. Snakes and lizards go into an inactive state of torpor during the winter, are active during the day during the late spring and early fall, and become crepuscular during the heat of summer. Many insects alter their times of activity. Mosquitoes, for example, may be out at night, at dawn, dusk or all day but not at night, depending on the temperatures.
Almost 50 species of mammal are known to live in Arches. Some, like desert cottontails, kangaroo rats and mule deer, are common and may be seen by a majority of visitors.
Arches’ hot climate and lack of water favors small mammals. Because of their size, these animals are less able to migrate, but have an easier time finding shelter and require less food and water to live. Rodents are numerous: there are eleven species of mice and rats alone.
Desert bighorn sheep live year-round in Arches, and are frequently sighted along Highway 191 south of the visitor center. These animals roam the talus slopes and side canyons near the Colorado River, foraging on plants and negotiating the steep, rocky terrain with the greatest of ease.
While Arches may not be considered a bird watching hot spot, 273 species have been seen in the park, including seasonal and year-round residents as well as migrants.
Arches owes much of this diversity to riparian corridors like Courthouse Wash and the Colorado River (which forms the park’s southern boundary). In the desert, animal life tends to concentrate around riparian areas because of the abundance of food, water and shelter. During spring and summer, mornings in these areas are filled with birdsong, including blue grosbeaks, yellow-breasted chats, spotted towhees and canyon wrens. Great blue herons may be seen hunting the shallows for fish, while cooper’s hawks deftly maneuver through the tangle of trees beyond the riverbanks.
Many birds favor the “upland” areas where grasses, shrubs and small trees dominate. Say’s phoebes, black-throated sparrows and western meadowlarks frequent grasslands. Pinyon jays, scrub jays, juniper titmice and black-throated gray warblers are usually seen in pinyon-juniper woodlands.
