Our Livini; RL'soitrces — hitt'iior WesI 



327 



and reptile inventory int'ormation for Colorado 

 Plateau parks vary. Grand Canyon National 

 Park has received moderately thorough survey 

 effort along the Colorado River coiridor (Miller 

 et al. 1982). but the canyon rim areas have 

 received relatively little study. Parts of Glen 

 Canyon National Recreation Area were sur- 

 veyed by the University of Utah (Woodbury 

 1959), but this information is now 35 years old. 

 Most other parks have had little or no thorough 

 survey work and a few, such as Rainbow Bridge 

 National Monument, have no inventory infor- 

 mation at all. The information for many park 

 species lists is based on large-scale range maps 

 or unverified records. We found incoiTcct iden- 

 tifications or outdated taxonomy on about 1 iWc 

 of the species recorded. The generally poor and 

 sometimes unreliable state of inventories in 

 many parks echoes the results of Stohlgren and 

 Quinn ( 1992) in a larger study. 



Sixty-two reptile and 18 amphibian species 

 are known from the Colorado Plateau as a 

 whole. Most occur in one or more of the nation- 

 al park areas. The few species that apparently 

 do not live in any parks, such as the mountain 

 treefrog (Hyla eximia). Chiricahua leopard frog 

 [Raiia chiricahuensis). and narrow-headed 

 garter snake (Thaumophis nifipunctatiis). are 

 primarily found in the area of the precipitous 

 Mogollon Riin in north-central Arizona, which 

 fomis the southern boundary of the plateau. The 

 most widespread species in the region include 

 Woodhouse's toad {Bujo woodhousii: 20 areas). 

 tiger salamander (Ambystoma rigriuiini: 16 

 areas), eastern fence lizard iSceloporus iiiulula- 

 tus\ 22 areas), tree lizard (Uwsaunis onuitiis: 

 21 areas), side-blotched lizard (Vta stausburi- 

 amr. 22 areas), striped whipsnake (Masticophis 

 taeniatiis; 21 areas), pine snake {Pituophis 

 melanoleiictis: 22 areas), and western rat- 

 tlesnake (Crotahis viridis; 22 areas). Some 

 other species are much more limited; for exam- 

 ple, the Jemez Mountains salamander 

 (Plethodon neomexicanus) is known only from 

 a small area of north-central New Mexico, 

 including Bandelier National Monument. The 

 painted turtle {Chrysemys pitta) is apparently 

 rare in the region and may have declined fur- 

 ther; there have been no recent reports of this 

 species from Glen Canyon National Recreation 

 Area, where it formerly occurred. Other 

 species, like the desert iguana (Dipsosaurus 

 dorsalis) and the Gila monster {Heloderma sus- 

 pectiim), only have a small portion of their 

 range on the Colorado Plateau (although they 

 occur within the geographic boundaries of the 

 area, some of these species are restricted to 

 habitats not representative of the plateau, such 

 as the Sonoran Desert). 



Four of the 62 reptile species (7%) are listed 

 as threatened or endangered by either individual 



states, the Department of the Interior, or both 

 (Table). In contrast. 5 of the 18 amphibian 

 species (27%) in the region are considered 

 threatened or endangered. The high proportion 

 of amphibians listed is due to several frog and 

 toad species that have experienced serious pop- 

 ulation declines. One of these, the relict leopard 

 frog (Raua onca) of southern Nevada, was 

 thought extinct but has recently been rediscov- 

 ered (D. Bradford. Environmental Protection 

 Agency, Las Vegas, Nevada, personal commu- 

 nication). The western toad (Bufo boreas) has 

 suffered drastic declines in other parts of its 

 range (e.g.. Carey 1993); its status on the 

 Colorado Plateau is not known. The northern 

 leopard frog (Rana pipiens). although not yet 

 listed by state or federal governments, has dis- 

 appeared from large areas of its range in west- 

 em North America (Hayes and Jennings 1986). 

 There are recent reports of healthy populations 

 in a number of the perennial streams on the 

 Colorado Plateau, but this species, in particular, 

 needs further survey. 



Figure. Tlie Colorado Plateau 

 region is cut by dramatic canyons 

 of the Colorado Ri\er system. 



.Northern leopard frog ( Raiui pipi- 

 ens). 



