In comparison with other North Americandeserts, the Great Basin has a depauperateherpetofauna consisting primarily of wide-ranging, habitat-generalist species (Stebbins1985). Great Basin amphibians and reptilesare often placed into broad groups based onoverall geographic distribution of the species,such as northern versus southern (Macey andPapenfuss 1991) or eastern versus western(Hovingh 1997). Many species occur only inthe periphery of the Great Basin Desert, wherethey are restricted to pockets of suitable habi-tat (Tanner 1978). Although general biogeo-graphic patterns can be seen, the subtle distri-butional nuances at local levels have yet to beelucidated for many species in the Great Basin(but see Hovingh 1997, Zamudio et al. 1997,Bos and Sites 2001). Distributions remainpoorly understood due to the relatively largearea encompassed and the scarcity of inten-sive inventory studies (e.g., Vindum and Arnold1997). Here we discuss the results of a her-petological survey of the southern SnakeRange and surrounding valleys conducted 20–25 May 2000.

The study area is situated in and aroundthe southern Snake Range, including GreatBasin National Park, in White Pine County,Nevada, and adjacent Millard County, Utah(Fig. 1). Physiography of the Snake Range istypical of the Basin and Range Province, beingcharacterized by abrupt north–south trendingmountains and their associated interconnect-ing valleys. The Snake Range is among thehighest in the Great Basin with peaks exceed-ing 3000 m in elevation. Snake Valley lies tothe east of the Snake Range and was formerlyinundated by ancient Lake Bonneville (Mifflinand Wheat 1979, Hovingh 1997). Spring Valley

flanks the western face of the Snake Rangeand is higher in elevation than Snake Valley(~1750 m compared to ~1525 m at low pointson the respective valley floors). Spring Valleylies outside the Bonneville Basin but was peri-odically inundated during the Pleistocene bysmaller, isolated pluvial lakes (Mifflin andWheat 1979, Hovingh 1997).

Survey crews recorded over 400 observa-tions of reptiles and amphibians during thecourse of this study. Most observations wererecorded during visual surveys in appropriatehabitat. Several additional observations resultedfrom driving roads at night and from inspect-ing beneath natural cover objects. We alsoattempted to listen for chorusing amphibiansin wetland habitats; however, when using thistechnique, we did not detect any animals. Atleast one specimen of each species capturedwas taken as a voucher. These specimens aredeposited at the California Academy of Sci-ences, San Francisco. Crews searched lowerand middle elevations (below 2500 m) of 7montane drainages of the southern Snake Range,concentrating efforts in the riparian zones andadjacent pinyon-juniper woodland of peren-nial streams draining the eastern slope of thesouthern Snake Range. We also surveyed vari-ous lower-elevation vegetative communities inSnake and Spring valleys.

We divided surveyed areas into 3 valleyand 2 montane habitat categories: low desertscrub, sagebrush shrubland, wetland, pinyon-juniper woodland, and montane riparian, re-spectively. Low desert scrub consists of com-munities dominated by Artemisia arbuscula,Atriplex sp., Sarcobatus vermiculatus, and Distichlis spicata. This habitat is prevalent atlow elevations in Snake Valley. We recorded

Western North American Naturalist 62(2), © 2002, pp. 234–239

HERPETOFAUNA OF THE SOUTHERN SNAKE RANGE OF NEVADAAND SURROUNDING VALLEYS

Kirk Setser1, Jesse M. Meik1, and Daniel G. Mulcahy1,2

Key words: Snake Range, Great Basin, herpetofauna, distributions, habitat associations.

1Department of Biology, Utah State University, Logan, UT 84322-5305.2Corresponding author.

234

Cnemidophorus tigris, Uta stansburiana,Phrynosoma platyrhinos, Crotaphytus bicinc-tores, Pituophis catenifer, Masticophis taenia-tus, Hypsiglena torquata, Crotalus viridis, andSpea intermontana from this habitat (Table 1).

Sagebrush shrubland occurs at higher ele-vations in Snake Valley and is prevalent onboth the floor and lower foothills of SpringValley. Artemisia tridentata typically domi-nates in this habitat, but other taxa includingA. arbuscula, Atriplex sp., Sarcobatus vermicu-latus, Ephedra sp., and various grasses arelocally abundant. We observed Cnemidopho-rus tigris, Uta stansburiana, Sceloporus gracio-sus, S. occidentalis, Phrynosoma platyrhinos, P.hernandesi, Crotaphytus bicinctores, Gambeliawislizenii, Pituophis catenifer, Thamnophis ele-gans, Crotalus viridis, and Spea intermontanain sagebrush shrubland (Table 1).

Several mixosaline wetlands occur in Springand Snake valleys. These habitats chiefly con-sist of persistent palustrine emergent wetlands

(Cowardin et al. 1978). Wetland complexes inSpring and Snake valleys include permanentlyflooded, intermittently exposed, semiperma-nently flooded, seasonally flooded, saturated,and temporarily flooded water regimes. Thesepalustrine wetlands also include open waterareas with a mixture of unconsolidated bottomand aquatic bed class wetlands. Open waterhabitats are generally small and shallow, andthey comprise a small portion of the total wet-land area. Juncus sp., Scirpus sp., Carex sp.,and various grasses characterize these areas.We encountered 2 native species in low-eleva-tion wetlands: Thamnophis elegans and Ranapipiens. A single introduced species, R. cates-beiana, was also seen in wetland habitat (Table1). Both species of ranid frogs were seen onlyin low-elevation wetlands.

On the upper foothills and in the canyonsof the Snake Range, woodlands of Pinus mono-phylla and Juniperus osteosperma replaceshrubland communities. Within most eastern

2002] NOTES 235

Fig. 1. Map of the southern Snake Range and surrounding valleys. Dots represent reptile and amphibian observationpoints, thus indicating areas surveyed. Thin lines represent major drainages, thick hatched lines represent roads, andthe solid line is the Nevada-Utah state border.

slope drainages of the southern Snake Range,these pinyon-juniper woodlands are relativelydense, dominated by P. monophylla, and con-fluent with riparian vegetation along water-courses. We recorded the following speciesfrom these pinyon-juniper woodlands: Scelo-porus graciosus, S. occidentalis, Uta stansburi-ana, Eumeces skiltonianus, Pituophis catenifer,Masticophis taeniatus, Hypsiglena torquata,Thamnophis elegans, and Crotalus viridis (Table1). Although we recorded U. stansburiana frompinyon-juniper woodland habitat, all observa-tions occurred in the open, juniper-dominatedwoodland of a single montane drainage.

Several perennial streams with well-devel-oped riparian zones dissect the eastern slopesof the southern Snake Range. Riparian plantcommunities differ substantially betweendrainages. However, most drainages are domi-nated by various combinations of Populus sp.,Salix sp., Betula occidentalis, and Prunus vir-giniana. Abies concolor is also prominent inhigher-elevation riparian communities. We

observed Sceloporus graciosus, S. occidentalis,Eumeces skiltonianus, Pituophis catenifer, Mas-ticophis taeniatus, Thamnophis elegans, andCrotalus viridis in montane riparian areas(Table 1); however, only T. elegans appearedconcentrated in this habitat. This contrastswith the observed trend among other snakespecies, which were relatively unrestricted byhabitat. No amphibian species were detectedin montane riparian habitats.

Species richness is greatest in sagebrushshrubland, followed by low desert scrub andpinyon-juniper woodland. Sagebrush shrub-land represents an interface between higher-elevation montane woodland and low-eleva-tion desert communities; most species en-countered in the latter habitats were alsofound in sagebrush shrubland. Xeric-adaptedlizard taxa typical of more southern NorthAmerican deserts, such as Cnemidophorus tigris,Uta stansburiana, and Phrynosoma platyrhi-nos, were encountered more frequently in lowdesert scrub than in any other habitat. Fewer

236 WESTERN NORTH AMERICAN NATURALIST [Volume 62

TABLE 1. Number of observations of reptile and amphibian taxa by habitat in the southern Snake Range and surround-ing valleys.

Low desert Sagebrush Pinyon-juniper Montanescrub shrubland wetland woodland riparian Total

Person hours searched 32.5 33.5 10.25 51.5 51 178.75

TEIIDAE

Cnemidophorus tigris 11 5 16PHRYNOSOMATIDAE

Uta stansburiana 61 21 21 103Sceloporus graciosus 41 76 2 119Sceloporus occidentalis 8 28 1 37Phrynosoma platyrhinos 16 2 18Phrynosoma hernandesi 1 1

CROTAPHYTIDAE

Crotaphytus bicinctores 1 1 2Gambelia wislizenii 1 1

SCINCIDAE

Eumeces skiltonianus 7 1 8COLUBRIDAE

Pituophis catenifer 9 16 3 2 30Masticophis taeniatus 2 1 1 4Hypsiglena torquata 1 1 2Thamnophis elegans 1 4 4 31 40

VIPERIDAE

Crotalus viridis 2 4 2 3 11PELOBATIDAE

Spea intermontana 3 2 5RANIDAE

Rana catesbeianaa 1 1Rana pipiens 8 8

ALL TAXA 106 104 13 142 41 406aIntroduced species

species were clustered in montane habitats.Eumeces skiltonianus was observed only athigher elevations, and we encountered Scelo-porus occidentalis primarily in montane habi-tats with only isolated observations from rockoutcrops at lower elevations in sagebrushshrubland.

Sceloporus graciosus is sympatric with S.occidentalis in montane habitats but alsooccurs extensively in sagebrush shrubland. Inareas of sympatry, S. occidentalis was encoun-tered only near rock outcrops and in areaswith extensive rocky terrain, while S. gracio-sus occupied more varied microhabitats. Wefrequently observed Uta stansburiana in open,juniper-dominated woodland habitat within asingle montane drainage; however, this specieswas not encountered in the relatively dense,pinyon-dominated woodland of other montanedrainages surveyed. Sceloporus graciosus issympatric with U. stansburiana within themontane drainage occupied by U. stansburi-ana, but it is apparently absent from the floorof Snake Valley, where the latter species wasfrequently encountered. Morrison and Hall(1999) also observed that U. stansburiana isassociated with open, juniper-dominated areaswithin pinyon-juniper woodland at sites in theWhite-Inyo Range of eastern California.

We observed notable differences betweenthe lizard assemblages of Snake and Springvalleys (Table 2), despite their being separatedby <30 km. We frequently encountered Utastansburiana, Phrynosoma platyrhinos, andCnemidophorus tigris on the floor of SnakeValley. We also observed these species athigher elevations in sagebrush shrubland ofSnake Valley, albeit less frequently. Althoughfew individuals were located, we observedCrotaphytus bicinctores and Gambelia wis-lizenii only in Snake Valley. In contrast to thecomparatively speciose lizard community ob-served in Snake Valley, only 2 lizard specieswere found in Spring Valley. We observed asingle P. hernandesi from the floor of the valleyand commonly observed S. graciosus at mostsites surveyed in Spring Valley. Many taxaseen in big sagebrush–dominated areas ofSnake Valley were not found in similar habitatof Spring Valley (Table 2).

In contrast, Phrynosoma hernandesi waslocated only in sagebrush shrubland on thefloor of the Spring Valley and was not ob-served in sagebrush shrubland habitats in

Snake Valley. Unsubstantiated reports of aPhrynosoma sp. exist from pinyon-juniperwoodland on the eastern slope of the southernSnake Range (B. Hamilton personal communi-cation). In addition, fossil records of Phryno-soma douglasi (likely P. hernandesi, sensuZamudio et al. 1997) have been found on theeastern slope of the southern Snake Rangeand from northern Snake Valley (Mead et al.1989). These records suggest P. hernandesilikely occurs on the eastern slope of the south-ern Snake Range and may also inhabit higherelevations of Snake Valley. Pianka and Parker(1975) noted that P. hernandesi and P. platyrhi-nos exhibit a complex distributional pattern atanother site in the eastern Great Basin. Inter-actions between these congeners may alsoinfluence their distributions and habitat affini-ties in the valleys surrounding the southernSnake Range.

Differences between Spring and Snake Val-ley lizard assemblages cannot be attributedsolely to disparity in elevation. All speciesfound in Snake Valley were observed at eleva-tions comparable to, or higher than, the floorof Spring Valley. This is particularly evidentwith Uta stansburiana, which occurs in themontane zone of at least one eastern slopedrainage of the southern Snake Range. Thereare obvious differences in the vegetative com-munities of Snake and Spring valleys. Thefloor of Snake Valley is largely covered byopen, low desert scrub dominated by Artemisiaarbuscula and sparsely vegetated halophyticplant communities. Spring Valley lacks theextensive open desert vegetation characteris-tic of Snake Valley. Instead, the floor of SpringValley includes large expanses of sagebrushshrubland and dense, comparatively mesichalophytic plant communities. The availabilityof dense shrub cover afforded by these com-munities may explain the presence of Scelo-porus graciosus and Phrynosoma hernandesi atlow elevations of Spring Valley.

Other dissimilarities exist between thesevalleys. Hotter and dryer than Spring Valley,Snake Valley is not bordered by a discreet,high-elevation mountain range to the east.Snake Valley contains rocky knolls with con-siderable topographical relief and is confluentwith the remainder of the Bonneville Basin.Spring Valley is a comparatively narrow valleybordered on both sides by high-elevationranges with a topographically uniform basin

2002] NOTES 237

floor, as is typical of valleys in the interiorGreat Basin. Some interaction of elevation,vegetation, temperature, and moisture likelyaccounts for the apparent absence of xeric-adapted lizard species, such as Cnemidopho-rus tigris, Uta stansburiana, and Phrynosomaplatyrhinos, in Spring Valley and their pres-ence in Snake Valley.

Many xeric-adapted taxa are widespread inthe lower-elevation Bonneville and Lahontanbasins of the eastern and western Great Basinbut are restricted in (or absent from) the inte-rior of the Great Basin (Banta 1962, Stebbins1985). Although data on herpetofaunal distri-butions in the Snake Range region remainlimited, we believe that the observed differ-ence between lizard taxa of Snake and Springvalleys reflects a real difference in lizard com-munity composition. The Snake Range maymark the eastern edge of the high-elevation,interior Great Basin that lacks components ofthe xeric-adapted herpetofauna typical ofsouthern North American deserts.

We thank N. Darby, B. Hamilton, J. Sirotnak,and staff of Great Basin National Park forinvaluable expertise and assistance. We thankT. Dahl, T. Grant, S. Newbold, C. Steele, C.Ustach, P. Ustach, N. Welch, A. Young, and K.Young for field assistance. We also thank C.Garrard for map assistance. The SouthernNevada Chapter of Trout Unlimited providedfunding. We thank the Brodie/Mendelson labgroup and 2 anonymous reviewers for com-ments on earlier versions of this manuscript.

LITERATURE CITED

BANTA, B.H. 1962. Preliminary remarks upon the zoo-geography of the lizards inhabiting the Great Basinof the western United States. Wasmann Journal ofBiology 20:253–285.

BOS, D.H., AND J.W. SITES, JR. 2001. Phylogeography andconservation genetics of the Columbia spotted frog[Rana luteiventris; Amphibia, Ranidae]. MolecularEcology 10:1499–1513.

COWARDIN, L.M., V. CARTER, F.C. GOLET, AND E.T. LAROE.1979. Classification of wetlands and deepwater habi-

238 WESTERN NORTH AMERICAN NATURALIST [Volume 62

TABLE 2. Presence of reptile and amphibian taxa in the southern Snake Range and surrounding valleys based on sur-vey data.

Snake Valley Spring Valley Snake Rangeb

Person hours searched 58.75 17.5 102.5

TEIIDAE

Cnemidophorus tigris XPHRYNOSOMATIDAE

Uta stansburiana X 1Sceloporus graciosus X X 6Sceloporus occidentalis X 6Phrynosoma platyrhinos XPhrynosoma hernandesi X

CROTAPHYTIDAE

Crotaphytus bicinctores XGambelia wislizenii X

SCINCIDAE

Eumeces skiltonianus 3COLUBRIDAE

Pituophis catenifer X X 3Masticophis taeniatus X 1Hypsiglena torquata X 1Thamnophis elegans X X 4

VIPERIDAE

Crotalus viridis X X 2PELOBATIDAE

Spea intermontana X XRANIDAE

Rana catesbeianaa XRana pipiens X

aIntroduced speciesbValues represent the number of montane drainages (of 7 surveyed) from which each taxon was recorded.

tats of the United States. U.S. Fish and Wildlife Ser-vice Report. FWS/OBS/-79/31. Washington, DC.

HOVINGH, P. 1997. Amphibians of the eastern Great Basin(Nevada and Utah, USA): a geographical study withpaleozoological models and conservation implications.Herpetological Natural History 5:97–134.

MACEY, J.R., AND T.J. PAPENFUSS. 1991. Amphibian andreptile biogeography. Pages 293–303 in C.A. Hall,Jr., editor, Natural history of the White-Inyo Range,eastern California. University of California Press,Berkeley.

MEAD, J.I., T.H. HEATON, AND E.M. MEAD. 1989. LateQuaternary reptiles from two caves in the east-cen-tral Great Basin. Journal of Herpetology 23:186–189.

MIFFLIN, M.D., AND M.M. WHEAT. 1979. Pluvial lakesand estimated pluvial climates of Nevada. NevadaBureau of Mines and Geology Bulletin 94:1–57.

MORRISON, M.L., AND L.S. HALL. 1999. Habitat character-istics of reptiles in pinyon-juniper woodland. GreatBasin Naturalist 59:288–291.

PIANKA, E.R., AND W.S. PARKER. 1975. Ecology of hornedlizards: a review with special reference to Phryno-soma platyrhinos. Copeia 1:141–162.

STEBBINS, R.C. 1985. Western reptiles and amphibians.3rd edition. Houghton Mifflin Company, New York.336 pp.

TANNER, W.W. 1978. Zoogeography of reptiles and amphib-ians in the Intermountain Region. In: K.T. Harperand J.L. Reveal, editors, Intermountain biogeogra-phy: a symposium. Great Basin Naturalist Memoirs2:43–54.

VINDUM, J.V., AND E.N. ARNOLD. 1997. The northern alli-gator lizard (Elgaria coerulea) from Nevada. Her-petological Review 28:100.

ZAMUDIO, K.R., K.B. JONES, AND R.H. WARD. 1997. Molec-ular systematics of short-horned lizards: biogeogra-phy and taxonomy of a widespread species complex.Systematic Biology 46:284–305.

Received 18 January 2001Accepted 20 December 2001

2002] NOTES 239