Colorado Plateau Shrublands Habitat
This taxon can be found in the Colorado Plateau shrublands, as one of its North American ecoregions of occurrence. The Plateau is an elevated, northward-tilted saucer landform, characterized by its high elevation and arid to semi-arid climate. Known for the Grand Canyon, it exhibits dramatic topographic relief through the erosive action of high-gradient, swift-flowing rivers that have downcut and incised the plateau. Approximately 90 percent of the plateau is drained by the Colorado River and its tributaries, notably the lower catchment of the Green River.
A pinyon-juniper zone is extensive, dominated by a pygmy forest of Pinyon pine (Pinus edulis) and several species of juniper (Juniperus spp). Between the trees the ground is sparsely covered by grama, other grasses, herbs, and various shrubs, such as Big sagebrush (Artemisia tridentata) and Alder-leaf cercocarpus (Cercocarpus montanus).
A montane zone extends over large areas on the high plateaus and mountains, but is much smaller than the pinyon-juniper zone. The montane vegetation varies considerably, from Ponderosa pine in the south to Lodgepole pine and Aspen further north. Northern Arizona contains four distinct Douglas-fir habitat types. The lowest zone has arid grasslands but with many bare areas, as well as xeric shrubs and sagebrush. Several species of cacti and yucca are common at low elevations in the south.
Numerous mammalian species are found within the Colorado Plateau shrublands ecoregion, including the Black-tailed prairie dog (Cynomys ludovicianus); Long-eared chipmunk (Tamias quadrimaculatus); Utah prairie dog (Cynomys parvidens EN); Yellow-bellied marmot (Marmota flaviventris); and the Uinta chipmunk (Tamias umbrinus), a burrowing omnivore.
A large number of birds are seen in the ecoregion, with representative taxa: Chestnut-collared longspur (Calcarius ornatus NT); Greater sage grouse (Centrocercus urophasianus NT); Northern pygmy owl (Glaucidium gnoma); Cactus wren (Campylorhynchus brunneicapillus).
There are various snakes occurring within the Colorado Plateau, including: Black-necked garter snake (Thamnophis cyrtopsis), usually found in riparian zones; Plains Blackhead snake (Tantilla nigriceps); Black-tailed rattlesnake (Crotalus molossus), who seeks inactivity refuge in rock crevices, animal burrows and even woodrat houses. Other reptiles found here include the Common checkered whiptail (Cnemidophorus tesselatus).
There are only a limited number of anuran taxa on the Colorado Plateau; in fact, the comprehensive occcurrence list for the ecoregion is: Red-spotted toad (Anaxyrus punctatus); Canyon treefrog (Hyla arenicolor); Woodhouse's toad (Anaxyrus woodhousii); Couch's spadefoot toad (Scaphiopus couchii); Northern leopard frog (Lithobates pipiens); Plains spadefoot toad (Spea bombifrons); and Southwestern toad (Anaxyrus microscaphus). The Tiger salamander (Ambystoma tigrinum) is the sole salamander found on the Colorado Plateau shrublands.
The Colorado River fish fauna display distinctive adaptive radiations. The Humpback chub (Gila cypha), for example, is a highly specialized minnow that lives in the upper Colorado. It adapted to the water’s fast current and its extremes of temperature and flow rate. Dams and water diversion, however, have created a series of placid, stillwater lakes and side streams, and the Humpback chub may not be able to adapt to these altered conditions. The species, along with other native Colorado River fishes including the Bonytail (Gila elegans), Squawfish (Ptychocheilus lucius), and the Flannelmouth sucker (Catostomus latipinnis), may not survive much further in time.