Amphibians may be the last thing people think of when they visit Canyonlands. However, the park is home to a variety of frogs and toads, as well as one species of salamander. Witnessing a chorus of toads may be one of the most memorable experiences canyon country has to offer. It is an awesome event that can fill a canyon with sound, sometimes for hours. In Canyonlands, amphibians lay their eggs in the potholes, springs and intermittent streams found throughout the park. Swift currents and predation limit survival during the larval stage in bigger rivers like the Colorado.
Adult amphibians may wander away from water, but usually remain nearby and wait out dry periods in burrows. Breeding (and toad choruses) usually occurs on spring and summer nights after significant rainfall. Male frogs and toads do the vocalizing. Females lay long strings of gelatin-covered eggs which, depending on the species, may hatch within hours. Metamorphosis can take weeks, though the Great Basin spadefoot toad transforms to adulthood in as little as 14 days, the quickest of any amphibian.
Lately, news headlines nationwide have featured stories about amphibians with strange mutations like extra or missing limbs, even extra heads. Dramatic population decline and even extinction have also become prevalent problems. The reason for these trends is unclear. However, studies indicate that amphibians are sensitive to a variety of environmental problems. An amphibian’s water-permeable skin makes it very vulnerable to both air and water borne pollutants. Increases in UV radiation may increase mortality of eggs and tadpoles of some species. Also, the metamorphosis between larval and adult stages is a delicate process that can be affected by environmental changes. Finally, since amphibians range over both terrestrial and aquatic territories, changes in either may affect populations.
Because of this sensitivity, amphibians have become “indicator species,” the health of which can be used to measure the health of an ecosystem. Thus far, neither mutations nor population declines have been observed at Canyonlands, but their importance as an indicator species has made preserving amphibian habitat a priority for the National Park Service.
In Canyonlands, amphibian populations are greatest along small perennial streams like those in Horseshoe Canyon near the Maze, and Salt Creek Canyon in the Needles District. To protect park resources, vehicle use in Horseshoe Canyon was prohibited in the 1970s, and vehicle use in Salt Creek Canyon was prohibited in June 1998.
Birds are the most visible animals in Canyonlands. Even on the hottest summer day, turkey vultures and white-throated swifts circle above the canyons. During winter, juncos and white-crowned sparrows forage around trees and shrubs. While Canyonlands 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.
Canyonlands owes much of this diversity to riparian corridors like the Colorado and Green rivers. 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 along the rivers are filled with birdsong, including blue grosbeaks, yellow-breasted chats, spotted towhees and canyon wrens. Great blue herons are often 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.
Since they are able to fly, it is difficult to generalize about what birds will be found in a particular habitat. However, regardless of habitat or season, the common raven figures prominently in the desert landscape. Ravens are intelligent birds that, according to scientists, display abilities to play and problem-solve rare among animals. This jet-black member of the crow family is also very vocal, using a variety of sounds for communication. Perhaps because of these qualities, ravens have achieved a certain stature in both European and Native American folklore.
Canyonlands monitors bird populations at several selected locations in both upland and riparian areas. Some surveys count all birds, while others focus on birds that actually nest in the park. Findings from these surveys and others like them are used to monitor the health of local bird populations and estimate species richness throughout the country.
The Colorado River and its tributaries are one of the world’s most spectacular river systems. From its headwaters in the mountains of Colorado and Wyoming, the river drops more than two miles on a 1,700-mile journey to the Gulf of California. The water becomes thick with sediment as it passes through the red rock canyons of the Colorado Plateau, and seasonal flow varies greatly. Before dams were built, flows ranged from a few thousand cubic feet per second to nearly 400,000 cubic feet per second.
Historically, only 14 species of fish inhabited the upper Colorado River basin, but over 40 non-native species have been added since the late 1800s. The native fish species in Canyonlands are primarily chub, minnows and suckers, and many are not found anywhere else. These include the Colorado pikeminnow (formerly squawfish), razorback and flannelmouth sucker, as well as humpback and bonytail chub.
There are several different niches within the underwater world of rivers. Razorback suckers and humpback chub prefer turbulent, swift water. Bonytail chub live in calm backwaters and eddies. Pikeminnows spawn in backwaters but roam throughout the river in search of food.
Until recently, pikeminnows were the dominant fish. Growing up to six feet long and weighing over 100 pounds, they could eat almost anything. The pikeminnow was called “Colorado salmon” by early settlers, probably because it migrated up to 200 miles through extreme white water to find its spawning grounds each year.
Today, non-native fish dominate the rivers. One study done at the Confluence in Canyonlands found 95 percent of the fish to be non-native. Carp and channel catfish are the most commonly seen. Carp are native to Asia and were hailed as the greatest food fish ever by the U.S. Bureau of Fisheries. Catfish are known to eat the young of several native species and have played a significant role in the decline of native fish populations. In the past few decades, the Colorado pikeminnow, razorback sucker, humpback and bonytail chub have all been listed as endangered species.
Almost 50 species of mammal are known to live in Canyonlands. Some animals, like desert cottontails, kangaroo rats and mule deer, are common and may be seen by a majority of visitors. However, many desert animals are inactive during daylight hours or wary of humans, so sightings can be truly special events. Tracks and scat are the most common signs of an animal’s presence.
Canyonlands’ hot climate and lack of water seems to favor 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 nine species of mice and rats alone. Beavers, the largest North American rodent, are found along the Colorado and Green rivers. Since the rivers are too swift and broad to dam, beavers burrow dens in the banks.
One animal uniquely adapted to life in the desert is the kangaroo rat. This rat lives its entire life consuming nothing but plant matter. Its body produces water by metabolizing the food it eats. However, even the kangaroo rat is prone to spending the hottest daylight hours sleeping in a cool underground burrow and may even plug the opening with dirt or debris for insulation.
Larger mammals, like mule deer and mountain lions, must cover more territory in order to find food and water, and sometimes migrate to nearby Along with cacti and sand dunes, snakes and lizards are icons of the desert. The only reptiles found in Canyonlands are snakes and lizards, underappreciated, sometimes feared, animals that play an important role in the high desert ecosystem. Lizards and snakes help control insect and rodent populations. In turn, both are potential meals for birds and mammals.
Of course, there are drawbacks to this lifestyle. Since they don’t pant or sweat, reptiles can’t endure extremely high temperatures without shade. Nor can they endure prolonged sub-zero temperatures. When it’s cold, reptiles hibernate or enter into an inactive torpor. Food stored as fat in their tails helps lizards survive these long periods of inactivity, so losing a tail can be life threatening.
Desert bighorn sheep live year-round in Canyonlands. These animals roam the talus slopes and side canyons along the rivers, foraging on plants and negotiating the steep, rocky terrain with the greatest of ease. Once in danger of becoming extinct, the desert bighorn are now making a tentative comeback that has been fueled by the healthy herds in Canyonlands.
An interesting fall visitor to Canyonlands is the black bear. An unusual sight in the red rock canyons, black bears follow river and stream corridors, like Salt Creek Canyon in the Needles District, that flow from nearby mountains. These visits generally occur in late August and September when prickly pear cacti and hackberry trees bear their fruit. The bears return to the mountains before winter.
If you visit Canyonlands during the summer, you are sure to see lots of lizards. After birds, these reptiles are the most active animals once daytime temperatures reach 90 degrees and higher. They are usually visible sunbathing on rocks or chasing insects with their lightning-quick reflexes. Lizards found here include the northern whiptail, the desert spiny, and the colorful western collared lizard.
Most of the snakes found in Canyonlands are harmless and nocturnal. All will escape from human confrontations given the opportunity. The midget-faded rattlesnake, a small subspecies of the western rattlesnake, has extremely toxic venom. However, full venom injections occur in only one third of all bites. The midget-faded rattlesnake lives in burrows and rock crevices and is mostly active at night.
All reptiles are cold-blooded or, more accurately, “ectothermic,” regulating body temperature via external sources rather than internal metabolism. A reptile’s metabolic rate is very low, but so are its energy needs. Since keeping warm in the desert does not require much work, reptiles are well adapted to this environment. What energy they do generate can be used for reproduction and finding food instead of heating and cooling.