Management of Amphibians, Reptiles, and Small Mammals in North America

Home , Igua, Masticophis flagellum

Abstract.-Between 1977 and 198 1, the Bureau of Distribution and Habitat Land Manaaement conducted extensive surveys of Associations of Herpetofauna Arizona's h&petofauna in 16 different habitat types on approximately 8.5 million acres of public lands. This paper describes results of one of the most exten- in Arizona: Corn~arisonsI by sive surveys ever conducted on amphibian and rep- Habitat Type1 tile communities in North America.

K. Bruce Jones2

With the passage of the Federal Land tats and are often good indicators of Policy and Management Act in 1976, habitat conditions (Jones 1981a). the Bureau of Land Management Therefore, in order to obtain infor- (BLM) was mandated to keep an in- mation on these animals, principally ventory of resources on public lands. for land-use planning, the BLM con- Information collected during inven- ducted extensive inventories of am- tories or surveys was then to be used phibians and reptiles by habitat type. to identify issues for land use plan- This inventory included a scheme ning and opportunities for land man- whereby associations between am- agement. The BLM made a decision phibians and reptiles and certain rni- to collect data on all major wildlife crohabitats could be determined. The groups and their habitats inventory, conducted between 1977 Early in the development of its in- and 1981, was one of the most com- ventory program, the BLM recog- prehensive surveys of herpetological nized a need to devise a strategy that communities ever conducted in would compare animal distributions North America (27,885 array-nights and abundance to habitats. This in 16 habitat types over a five-year strategy was important since the period). It also represents the first BLM manages wildlife habitats and large-scale effort to quantitatively not wildlife populations. compare herpetofaunas associated In 1977 the BLM initiated invento- with ecosystems. This paper reports ries of wildlife resources on public the results of these surveys, includ- lands. At that time, considerable in- ing species distributions and associa- formation was already available on tions with microhabita ts and habitat Figure 1 .-The study area. game species. However, data on types (plant communities). nongame species were mostly lack- ing. As a result, priority was given to those presented by Brown et al. collecting data on nongame species STUDY AREA (1979). For example, because of the and their habitats. scale of their map, Brown et al. (1979) Amphibians and reptiles are im- The study area consisted of approxi- failed to recognize several small, rel- portant members of the nongame mately 3,441,296 ha (8.5 million ict stands of chaparral woodland, fauna. They use a wide range of habi- acres) of public lands located in cen- although Brown (1978) had noted the tral, west-central, southwestern, and presence of chaparral woodland 'Paper presented at symposium, Man- northwestern Arizona (fig. 1). Sixteen vegetation at several small sites (see agemen t of Amphibians, Reptiles, and different habitat types were deline- Jones et al. 1985 for the importance of Small Mammals in North America. (Flag- staff, Arizona, July 1 9-2 ?, 1 988). a ted within this area, primarily from small woodland stands to certain 2K. Bruce Jones is a Research Ecologist an existing map of vegetation asso- herpetofauna). Therefore, the habitat with the Environmental Protection Agency, ciations (Brown et al. 1979). Field re- type map used to allocate samples in Environmental Monitoring Systems Labora- connaissance allowed more local as- this study drew upon the Brown tory, Las Vegas, Nevada 89193. sociations to be recognized within (1978) and Brown et al. (1979) maps, and results of field reconnaissance. of 18.3 1 (5 gal) plastic containers bur- mary of sampling effort in each habi- For detailed descriptions of these ied in the ground and connected by tat type). Arrays were placed so that habitat types see Jones (1981b) and 0.41 m (8 inches) high aluminum microhabitat variability within each Buse (1981). drift fence; one trap was located in habitat type was sampled. The num- the center with three evenly dis- ber of arrays used to sample habitat persed (120") peripheral traps 7.14 m types was par tially influenced by the SAMPLING METHODS (25 ft) from the center (Jones 1981a, size of habitats; generally, more ex- Jones 1986).This modified array tensive habitats received proportion- Amphibian and reptile distribution method was designed specifically for ally larger samples. However, certain and abundance by habitat type were sampling amphibians and reptiles in habitats (e.g., riparian) were known determined by on-the-ground Sam- desert habitats (see Jones 1986 for a to be great sources of diversity pling efforts between October, 1977, comparison of this procedure with within desert regions; therefore, pri- and July, 1981. Samples were ob- the original array trapping scheme ority was given to obtaining larger tained by three methods. The most designed by Christman and samples within these habitats. Once extensive sampling was accom- Campbell 1982). A total of 183 arrays placed into the ground, arrays were plished with a pit-fall trapping were used to sample 16 different continuously open for a minimum of method (array) consisting of a series habitat types (see table 1 for sum- 60 days. Some arrays (60) were open for 9 months. Generally, samples were taken during the spring, summer, and fall. However, some arrays (17) were open only during spring months and others only in the fall (12). The opening of new arrays at different locations, and the closing of other arrays, were often dictated by BLM's predetermined resource planning schedule. Since some amphibians and many snakes could not be effectively sampled by pit-fall traps, it was nec- essary to use two other field techniques. Road riding, consisting of traveling roads from dusk to approximately 2300 h throughout de- lineated habitat types, was used to determine the occurrence of amphibians and medium and large snakes (see table 1 for sampling effort within each habitat type). Time-constraint searches (Bury and Raphael 19831, consisting of walking along permanent and tem- porary water sources (natural and man-made) at night, were used to verify the presence of frogs and toads at waters within habitat types (see table 1 for sampling effort within each habitat type). Finally, to get an idea of the known distribution of amphibians and reptiles within the study area, I obtained records from 7 museums known for their outstanding collec- tions of amphibians and reptiles from the Southwest: the University of Michigan, Arizona State University, the total number of any species lar to arrays, only array data were the University of New Mexico, caught during a 24-hour period (ar- used to calculate species diversity. Northern Arizona University, the ray-night). Relative abundance was Two types of cluster analysis were University of Arizona, the Los Ange- determined for each species on array used to determine similarities among les County Museum, and the Univer- sites by taking the greatest number of habitat types. The first cluster analy- sity of California at Berkeley. In addi- individuals of a species trapped dur- sis was performed only on array tion, these data wcre used to com- ing a 30-day period and dividing by data, and it was based on euclidean pare the past distribution of amphibi- the number of days. This calculation distances (Pimental 1979). Calcula- ans and reptiles within the study was used because of monthly differ- tion of euclidean distances between area with that obtained during the ences in species' activity patterns. hahitats wcre based on a combina- BLM's inventories. The number of arrays in which a spe- tion of species' presence or absence Microhabitat data were collected cies was trapped in each habitat type on a site and similarity in species' on each array site and along roads by also was compiled to determine how dominance (relative abundance) be- a modified point-intercept method widespread a species was within in- tween habitats. Since medium and consisting of 100 sample points sepa- dividual habitat types. large snakes (> 0.5 m or 1.5 ft) are not rated by 8 m (26 ft) along a randomly A principdl components analysis readily caught in pit-ball traps, their determined compass line; on array (Pimental 1979) was performed to relative abundances could not be cal- sites, the center of the line crossed compress microhabitat data into a culated accurately. To compare the over the array. At each point, the fol- smaller, depictable subset. Mean fac- overall herpetofaunas of habitat lowing measurements were taken: (1) tor scores of compressed microhabi- types, a second cluster analysis was vertical distribution of vegetation be- tat data were computed for each performed. This procedure involved tween 0-0.6 m (0-2 ft), 0.6-1.7 m (2-6 habitat type and plotted on a 3 vector calculation of Simpson similarity co- ft), 1.7-6.0 m (6-20 ft), and > 6 m (20 (axis) graph. Similarly, mean factor efficients (Pimental 1979). These coef- ft) (each time vegetation occurred in scores of compressed microhabita t ficients were then submitted to a a height class above the point, a con- data were computed for each am- cluster analysis. Unlike the analysis tact or "hit" was recorded); (2) pene- phibian and reptile species (turtles of array data via euclidean distances, tration to the nearest cm into the soil were excluded because aquatic mi- the use of Simpson similarity coeffi- by a pointed metal rod (1 cm in di- crohabitats were not measured). cients in a cluster analysis did not ameter); (3) depth of leaf litter (if These scores were calculated for each consider relative dominance in calcu- present); (4) depth of other litter such species by averaging mean factor lating distances between habitats. as debris heaps (piles of logs, leaves scores for microhabitats on which a Several thousand site specific dis- and other dead vegetative material) species occurred. tributional records were obtained for and rotting logs; (5) characterization Species richness (total number of amphibians and reptiles within the of surface rock into size classes of species) and species diversity were study (to 16.2 ha or 40 acre accu- sand, gravel (< 1 cm or 0.4 inches in calculated for each habitat type. Two racy). These individual records were diameter), cobble (1 to 5 cm or 0.4 to calculations of species richness for too numerous to report here; detailed 2 inches in diameter), stone (> 5 cm habitats were used; one that used locality records for each species are or 2 inches in diameter), and bed- only array data and one that used all kept at the Bureau of Land Manage- rock. Vegetation cover and percent- data (array, road-riding, and field- ment" Phoenix District Office. age of the surface occupied by each search data). In addition, the average rock and litter size class was deter- number of species collected per array mined by comparing the number of (30-day period) was calculated and RESULTS "hits" in each category (e.g., litter) compared to overall, array-deter- with the total number of sample mined, species richness. Species di- Microhabitats points (100). Plant species were also versity of each habitat was deter- recorded along each 100 point mined from a Shannon-Weaver di- A principal components analysis transect (see table 1 for the number versity index (Hair 1980): H' = 6 p, (PCA) of microhabitats yielded 3 of microhabitat samples taken in log,, pi; where s = the number of spe- compressed habitat components each habitat type). cies and pi is the proportion of the (axes), and the cumulative propor- total number of individuals consist- tion of eigcnvalues was < 1.0 with ing of the ithspecies. Average species 83% of the variability accounted for DATA ANALYSIS diversity per array was calculated for by the matrix (p < .05). This analysis each habitat type. Because road-rid- revealed large differences in the mi- I calculated relative abundance of ing and field searches did not yield crohabitat among habitat types (fig. each amphibian and reptile species as estimates of relative abundance simi- 2). Desert grassland, disclimax desert grassland, and creosotebush habitats rnagister, Urosaurus ornatus, U2a fiemidophorus burti and Eumeces ob- had open canopies and low-height stansburiana, and Cnemidophorus tigris soletus, had limited distributions vegetative structure, whereas were the most widely distributed within the study area (table 2); C. pinyon-juniper, mixed riparian and abundant lizards throughout the burti is principally distributed in the scrub, cottonwood-willow riparian, study area's habitat types (table 2). Sonoran Desert and Desert Grass- mixed broadleaf riparian, and pon- These lizards also consistently oc- lard habitats in extreme southern derosa pine had tree canopies and curred on a large number of sites Arizona and Mexico, and E. obsoletus large amounts of vegetative debris, within each habitat type (table 2). only occurs in the chaparral habitat such as leaf litter and logs, on their Certain lizards, such as Gambelia wis- type in the extreme eastern portion surfaces (fig. 2). Closed and open lizeni, Ph ynosoma solare, and Dip- of the study area. Although re- chaparral habitats consisted of sosaurus dorsalis occurred only on stricted to higher elevation and ripar- shrubs with rocky surfaces, and lower elevation (c 915 m or 3000 ft), ian habitats throughout most of the Sonoran Desert had a combination of desert habitats, and other lizards, study area, C. texam was found in trees and shrubs and rocky surfaces such as Sceloporus undulatus, Gerrhon- Sonoran Desert in the extreme east- (fig. 2). otus kingi, and Ph ynosoma douglassi ern portion of the study area. Most occurred only on higher elevation (> lizards occurred throughout the 1220 m or 4000 ft) habitats (table 2). study area where suitable habitat Species Distributions and Some species, such as Eumeces gilberti was present and were not restricted Abundances and Cophosaurus texana, were princi- by geographic range. pally found on higher elevation habi- A PCA revealed that lizards dif- A total of 28 species of lizards, 30 tats, but also inhabited cottonwood- fered in their associations with cer- snakes, 4 turtles, 9 toads, 3 frogs, and willow riparian habitats at lower ele- tain microhabitats (fig. 3). Some of 1 salamander were observed or vations (549-915 rn or 1800-3000 ft) the widely distributed species, such trapped during the study. Sceloporus (table 2). Certain lizards, such as as Cnemidophorus tigris and LIta stansburiana, showed little association with any of the principal components (fig. 3), although the distribution of other common species, such as Sce- loporus magister and Urosaurus ornatus was highly correlated with the presence of vegetation debris (fig. 3). More than half of the lizards occurred on sites with relatively open canopies and shrubs or grasses, and many also preferred rocky substrates Grasses (fig. 3). Dipsosaurus dorsalis, Callisau- Shrubs/ rus draconoides, and Gambelia wislizeni occurred on sites with sand substrate. Gerrhonotus kin@ and Eumeces gilberti occurred on sites with large amounts of vegetative debris, medium to high canopies, and rocky substrates, and Xantusia vigilis on sites with similar substrate but with a more open canopy (fig. 3). Crotaphytus collaris and Sauromalus obesus occurred on sites that were open, rocky, and shrubby or grassy (fig. 3). 50 -.25 0 .25 .50 ,75 Vegetative Debris Snakes showed similar distributional patterns to lizards. Some Component II snakes, such as Lampropeltis getulus, Pituophis melanoleucus, Rhinocheilus Figure 2.-Mean factor scores of microhabitats for habitat types. (Abbreviations correspond leconti, Crotalus atrox, and CrotaZus to those listed for habitats in table 1 .) molossus, occurred in many habitat

types. Others, such as Chilomeniscus cinctus, Chionactis occipitalis, Phyl- lorhynchus browni, Phyllorh ynchus decurtatus, and Crotalus cerastes, occurred primarily on lower elevation (< 915 m or 3000 ft), desert habitats, and some, such as Lampropeltis py- Component I romelana and Crotalus viridis cerberus, occurred only on higher elevation (~1525m or 5000 ft) habitats (table 3). Lichanura trivirgata and P. browni occur primarily outside the study areas, and their distributions only overlap the extreme southern and southwestern portions of the study area. Therefore, they were limited to the small number of sites with suitable habitat. Thamnophis cyrtopsis and Thamnophis marcianus were restricted Component Ill to sites with water, with the former occurring on a large number of habitats and the latter only in a mesquite bosque habitat along the Gila River south of Phoenix. Similar to Copho-, saurus texana, Tantilla hobarfsrnithii was found on higher elevation / I I I I I I i \ (>I220 m or 4000 ft) and riparian rn -.75 -.a -25 0 25 5Q . %&b* habitats throughout most of the Oebb study area, but also in Sonoran Des- ert in the eastern portion of the study Component II area. A PCA of microhabitats on which Figure 3.-Mean factor scores of microhabitats for lizards. snakes occurred revealed that, simi-

Arizona elegans 46 Tantilla hobartsrnithij lar to those of lizards, rnicrohabitat Chilomeniscus cinctus 47 Thamnoph~scyrtops~s Chionacfis occi italis 48 Tharnno his marclanus associations differed among snakes Dladqph~spuncfbtus 49 ~rirnor~iodonbiscutatus larnbdc (fig. 4). Many of the widely distrib- Hypslglena torquata 50 Crotalus atrox Lampropeltis getulus 51 Crotalus cerastes uted snakes, such as Hypsiglena Lampropeltis pyromelaM Crotalus rnitchelli torqua fa, Lampropeltis getulus, Mastico- Lichanura. triv!r-gata 53 Crotalus rnolossus Mastlcoph~sbhneatus 54 Crotalus scutulatus phis flagellum, and Pituophis melano- Masticophis flagellum 55 Crotalus tigris Masticophis taeniatus 56 Crotalu~viridis cerberus leucus, showed no strong rela tionship Pltuoph~smelanoleucuSJ7 Mlcruroldes euryxanthus with any of the compressed habitat Phyllorhynchus browni 58 Leptotyphlops hurnilis Phyllorhynchus decurtatus components (fig. 4). Conversely, Component I Rhmocheilus leconti Salvadora hexalepis most species with limited distribu- Sonora semiannul@ tions showed a strong relationship I with certain components (fig. 4). Chionactis occipitalis, Crotalus cerastes, Crotalus scutulatus, and Phyllorhyn- chus browni consistently occurred on open, sandy sites, and Chilomeniscus cinctus occurred on sites with sandy substrate but taller canopy (fig. 4). Other species, such as Crotalus mitch- elli and Sonora semiannulata, were found on sites with open canopies but rocky substrates (fig. 4). Tharnno- phis marcianus and Tantilla hobartsmithii occurred on sites with sandy substrates but closed canopies / I 1 I I I I I open 75 Veg*M and large amounts of vegetative de- Cmw -n -50 - 25 0 25 50 mbfb bris, and Lampropeltis pyromelana oc- Component II curred only on sites with high amounts of vegetative debris (fig. 4). Figure 4.-Mean factor scores of microhabitats for snakes. Other species, such as Diadophis punctafus, Tharnnophis cyrtopsis, and as Ruf~punctatus and Scaphiopus vegetation debris (fig. 5). Certain Crotalus viridis cerberus, occurred on couchi occurred in a large number of species, such as Scaphiopus couchi, rocky sites with high amounts of habitat types, most species were Bufo alvarius, and Bufo woodhousei oc- vegetative debris (fig. 4). found in at least one lower (< 915 m curred on sites with a wide variety of Except for a single Gopherus agas- or 3000 ft) and one higher (> 1220 m substrates (fig. 5). sizii captured in an array, all turtle or 4000 ft) elevation site (table 5). The occurrence and frequency of records came from road-riding and Similar to lizards and snakes, there water was not quantitatively meas- field searches. Four species of turtles are some amphibians whose ranges ured at each site; therefore, the influ- were recorded within the study area, are principally outside the study area ence of water was not considered in three aquatic and one terrestrial and are, therefore, found only on a the development of figure 5. How- (table 4). Of these, G. ngassizii was the few sites (table 5). The ranges of Bufo ever, all sites with amphibians had most widely distributed (verified in 9 debilis, Bufo retiformes, and Gastro- surface water during some part of habitat types, table 4). A more thor- phyrne olivacea are primarily in north- the year, especially during summer ough account of this turtle's distribu- ern Mexico, or east and south of the months. All sites with Bufo mi- tion is described by Burge (1979, study area in the Chihuahuan Desert; croscaphus, Ram pipiens, R. catesbe- 1980).Pseudernys scripta, an intro- within the study areas, their ranges iana, and Hyla arenicolor had perma- duced species, was limited to a are limited to desert grassland habi- nent water (e.g., springs, creeks, and stretch of the Gila River from the tats in the extreme southern portion rivers). 99th Street bridge in southwest Phoe- (Vekol Valley, 48 km or 30 mi west- At the start of the survey in 1977, nix to Gillespie Dam, located ap- southwest of Casa Grande). All populations of Bufo microscaphus and proximately 24 km (15 miles) south populations of Ambystoma tigrinum B. woodhousei syrnpatric on major of Buckeye. Trionyx spiniferus oc- were located at earthen stock tanks drainages, such as the Hassayampa, curred at Alarno Lake (confluence of (dirt tanks). Presumably, all of these Santa Maria, Agua Fria, and New the Big Sandy and Santa Maria rivers populations were introduced. rivers, could be easily distinguished in western Arizona) and along peren- A PCA demonstrated correlations from one another. By 1981, popula- nial stretches of the Gila River from be tween occurrence of amphibian tions on all of these drainages were Phoenix to Yuma. Kinosternon sonori- species and particular microhabitats indistinguishable. ense occurred on several permanent (fig. 5). Bufo debilis, B. refiformes, and streams and rivers throughout the Gastrophyrne olivacea occurred on study area. sandy, grassy sites, and Bufo cognatus Range Extensions In contrast to the observed distri- on sandy, shrubby sites (fig. 5). Bufo bution patterns among lizards and microscaphus and B. punctatus oc- Thirty-five range extensions were snakes, the distribution of amphibi- curred on rocky sites, and Hyla areni- recorded for amphibians and reptiles ans did not shown an elevational pat- color on rocky sites generally occu- within the study area. Except for the tern. Although certain species such pied by trees and large amounts of following discussion, range extensions discovered during this study (25 acres) open chaparral habitat in Mountain in a relict desert grassland have been described elsewhere (Jones the Eagletail Mountains (fig. 6). The habitat (fig. 6). This population ex- et al. 1981, Jones et al. 1982, Buse westernmost distribution of Cnemido- tends the known distribution of this 1983, Jones et al. 1983, Jones et al. phorus burti was extended from the subspecies approximately 100 km (62 1985). The southernmost distribution Tucson area northwest by discovery mi) to the north of the only other of Tantilla hobartsmithii was extended of isolated populations in desert known population (Ajo Mountains). from the Salt River east of Phoenix, grassland habitats on summits of the Finally, an isolated population of southwest in the mesquite bosque Tabletop and Estrella mountains (fig. Diadophis punctatus was discovered habitat along the Gila River to 56 km 6). in a relict desert grassland commu- (35 miles) east-northeast of Yuma An isolated population of Mastico- nity on the summit of the Estrella (fig. 6). A population of T. hobart- phis bilineatus lineolatus was discov- ~ountainssouthwest of Phoenix (fig. smithii was also discovered in a 10 ha ered on the summit of Tabletop 6). Comparison of Habitat Types greatest number of turtle species A more revealing statistic is the (four species, fig. 7). average number of species verified Based on data compiled from pit-fall When only array data are com- by an array (fig. 8). This analysis re- trapping, road-riding, and searches, piled, disclimax desert grassland, veals which habitats consistently had the Sonoran Desert habitat had the sagebrush, and ponderosa pine habi- the largest number of species at greatest species richness (49 species, tats still had by far the lowest num- sample sites. Certain habitats, such fig. 7). Closed chaparral and cotton- ber of species, but Sonoran Desert as desert grassland, although high in wood-willow riparian habitats were and mesquite bosque had the great- overall species richness, had rela- the second richest habitats (44 spe- est number of species (fig. 8). As tively few species verified at each cies), and open chaparral and mixed when all data were taken into ac- array site (fig. 8). Other habitats, riparian scrub were third (41 species, count, mixed riparian scrub, cotton- such as ponderosa pine, sagebrush, fig. 7). wood-willow riparian, closed chap- and disclimax desert grassland, had Disclimax desert grassland had arral, and open chaparral had high the lowest number of total species the fewest species (81, and sagebrush species richness (fig. 8). However, and the lowest average number of and ponderosa pine had the second desert grassland was relatively more species per array site (fig. 8). Many of and third fewest species (13 and 15 diverse using only array data (fig. 8). the habitats that had high overall species, respectively, fig. 7). All other The difference between array vs. species richness also had high overall habitats had at least 27 species but all data appears to result from the richness at each array site; however, not more than 39 (fig. 7). Although inability of arrays to consistently ver- cottonwood-willow had a higher av- Sonoran Desert had the richest lizard ify (trap) turtles and medium and erage number of species per array and snake faunas, mesquite bosque large snakes, although many larger site than did Sonoran Desert (fig. 8). and desert grassland habitats had the snake species were verified because Species diversity indices (H') cal- richest amphibian fauna (fig. 7). The young-of-the-year were easily culated from array data reveal pat- mesquite bosque habitat type had the trapped. terns similar to those described above (fig. 9). Disclimax desert grassland, sagebrush, and ponderosa pine continue to exhibit low diversity, and Sonoran Desert, closed chaparral, cottonwood-willow riparian, mixed riparian scrub, and desert grassland continue to be diverse (fig. 9). How- ever, as in the previous analysis, the average diversity per array site is low when compared to total diversity for individual habitats (fig. 9). Of the habitats with high overall diversity, mixed broadleaf riparian and cottonwood-willow riparian had relatively high average diversity per array site (fig. 9). A comparison of herpetofaunas of each habitat type by cluster analyses Component Ill revealed that all desert habitats, such as creosotebush, Sonoran Desert, Mohave Desert, and mixed riparian scrub had very similar herpetofaunas (figs. 10 and 11). In both cluster analyses, open and closed chaparral had similar herpetofaunas, and sagebrush and disclimax desert grassland Open ii had a herpetofauna different from Conopy -.75 any other habitat. However, there Component II were differences in results of the two cluster analyses for other habitats. Figure 5.-Mean factor scores of microhabitats for amphibians. Whereas the cluster analysis of array data revealed large differences be- Number of Species tween the herpetofaunas of cottonwood-willow and desert habitats, such as Sonoran and Mohave Des- erts, these habitats had a relatively moderate degree of overlap when all data were analyzed (figs. 10 and 11). Additionally, ponderosa pine and pinyon-juniper habitats were similar Snakes when array data were analyzed and relatively dissimilar when all data were submitted to cluster analysis (figs. 10 and 11).

DISCUSSION

Overall, western Arizona has an ex- tremely diverse herpetofauna, primarily because of its large variety of habitats zoogeographic location. The Hualapai Mountains, located in PF' PJ S8 CC OC DG OD MB CW JM CA M MR MD SD CB northwestern Arizona, are adjacent to three major deserts: the Mohave Habitat Type Desert to the northwest, the Great Basin Desert to the northeast, and the Figure 7.-Number of species by taxonomic group by habitat type. (Abbrev. correspond to Sonoran Desert to the south. No- those listed for habitats In table 1 .) where else on the North American continent does such a phenomenon Number of Species exist. The diversity of habitat in this area is also enhanced by the occurrence of several woodland islands. 30 ,

Ave # of species1 array

PP PJ SB CC OC DG DD MB CW JM CA ME MR MD SD CB

Habitat Type

Figure 8.-Total number of species caught in arrays by habitat type vs. the average number of species caught per array by habitat type. (Abbrev. correspond to those listed for habitats Figure 6.-Map of range extensions. in table 1.) Species Diversity (HI) Patterns of Species Distributions This survey reveals that certain spe- Totd Species cies are widespread, occurring in DiversiW (H') several habitats, but many species

Ave Diversity, are limited to specific habitat types. Array Also, some species occur on most sample sites within a habitat type and others on only a few. There appear to be at least 3 major factors contributing to distributional patterns of amphibians and reptiles in the study area.

Geographic Limitations

The ranges of certain species only peripherally occur in western Arizona. Cnemidophorus burti, Phyl- lorhynchus browni, Masticophis bilinea- W PJ SB CC OC DG DD ME CW JM CA ME MR MD SD CB tus lineolatus, and Bufo retifomis occur principally in northern Mexico Habitat Type whereas others such as Holbrookia maculata, Eumeces obsoletus, Gastro- Figure 9.-Total species diversity (H') by habitat type vs. average species per array by habi- phyrne olivacea, and Bufo debilis are tat type. (Abbrev. correspond to those listed for habitats in table 1 .) mostly east and north of the study area (Stebbins 1985). Bufo retiformis, Gastrophyrne olivacea, and Bufo debilis Similarity are associated with low elevation (457-915 m or 1500-3000 ft) desert grassland (Jones et al. 1983), and 1.o these habitats are mostly absent in the central and northern portions of .9 the study area. However, habitat suitable for other species listed above .8 appears to be available throughout most of the study area. .7 Physical barriers, such as topogra-

.6 phy, elevation, and climate may have presented these species from coloniz- .5 ing or immigrating into suitable habitats to the north and west (see Con- .4 nor and Simberloff 1979, Case 1983, Jones et al. 1985 for discussion of the .3 influence of physical barriers on colonization/immigration). In addition, .2 competition between species may have limited individual species' 1 ranges during initial and subsequent 0 colonization of suitable habitats (e.g., during periods of large climatic changes). Perhaps the best example Figure 10.-Cluster analysis (dendrogram) of array data illustrating similarities in habitat type of this is the distributional relation- herpetofaunas. (Abbrev. correspond to those listed for habitats in table 1 .) ship between Eumeces gilberti and E.

121 obsoletus. E. gilberti belongs to the pears that these lizards are mutual determining the number of upland skiltonianus group of skinks, whose exclusive (competitive exclusion). present species (see Jones et al. 1985). evolutionary center is the western Several remnant stands of chapar- The turtles Pseudernys scripfa and United States (Taylor 1935, Rogers ral and desert grassland occur in Trionyx spiniferus are present along and Fitch 1947). western and northwestern Arizona at the Gila River as a result of Conversely, E. obsoletus evolved in or near the summits of mountain introductions. P. scripfa is a popular the Great Plains region (Fitch 1955). ranges. These relict stands or habitat pet, and specimens have been re- Both of these lizards occupy seem- islands are isolated within creo- leased along the Gila River in south- ingly identical, but separate, habitats sotebush and Sonoran Desert habi- west Phoenix. T. spiniferus was intro- in central Arizona, and their distribu- tats as a result of the retreat of the duced along the Colorado River in tions come together in chaparral and last Ice Age (see Van Devender and the early 1900's (Stebbins 1985); prc- desert grassland habitszt types near Spaulding 1977). Data collected in sumabl y, these populations ex- Cordes Junction; the westernmost my study show that several reptiles panded into the Gila River at the range of E. obsolefus is just east of typically found in "upland" habitats confluence of the Gila and Colorado Interstate Highway 17 and the east- (e.g., large continuous stands of des- rivers near Yuma. ernmost range of E. gilberti is just ert grassland and woodlands associ- west of the highway. These lizards ated with the Colorado Plateau of are similar in appearance, with E. ob- central and northern Arizona) inhabit Microhabitats and Physical solefus averaging slightly larger in these isolated mountain stands, al- Characteristics of Habitat size. though the number and composition Although subtle differences in mi- of these upland species vary among Many studies have shown a strong crohabitat cannot be ruled out as fac- mountains. Habitat island size ap- relationship between the distribution tors influencing their ranges, it appears to be of primary importance in and abundance of amphibians and reptiles and the presence and amount of certain microhabitats (Norris 1953, Similarity Pianka 1966, Zweifel and Lowe 1966, Fleharty 2967, Pianka and Parker 1972).The distribution of a number of species within western Arizona area appears to be influenced by the presence of microhabitats on sites, although most of the widespread species, such as Cnemidophorus tigris, Pituophis melanoleucus, and Lmn- propel tis get u lus show no strong relationship with any specific kabj tat components, others (e.g., Urosaurus ornatus and Sceloportls magister) occur on sites with trees and downed litter. Many sites in the study area, includ- ing desert and upland habitat types, have trees and downed logs, and this probably accounts for these species' wide distributions. The habitat analysis revealed that several species are assscia ted with specific substrate types (e.g., rock), density or height of the vegetation canopy, type of vegetation (shrubs or grasses vs. trees), or presence of downed litter. Species' associations with certain miciohabitats may reflect their physical or behavioral limitations. For Figure 1 I .-@luster analysis (dendrsgram) of all data illustrating similarities in habitat type example, Eumeces gilberfi may be re- herpetofaunas. (Abbrev. correspond to those listed for habitats in table 1 .) stricted to sites with large amounts of downed litter (primarily leaves ran Desert habitats within the study occurred on less than half of the cot- and logs) because of its low preferred area are more extensive than those to tonwood-willow and mixed riparian body temperature and feeding habits the west and northwest, and they are scrub array sites. The habitat analysis (Jones 1981b, Jones and Glinski 1985). not interrupted by large creo- shows that this species is associated Large amounts of surface litter on sotebush habitats; western and with sandy and fine gravel soils, but certain riparian sites may explain the northwestern sites are restricted many of the cottonwood-willow ri- occurrence of this lizard in cotton- mostly to mountain slopes, separated parian and mixed riparian scrub wood-willow riparian sites within by extensive creosotebush flats. In sample sites have rocky substrates. desert regions (down to 549 m or addition, eastern and southeastern Therefore, the substrate type limits 1800 ft) (see Jones and Glinski 1985). sites appear to have more springs this speciesf range within these habi- Several other species typically found and perennial creeks than western tat types. on upland habitats (eg., chaparral), and northwestern sites, and this ad- However, there were other spe- such as Tantilla hobartsmithii, Copho- ditional moisture might contribute to cies, especially snakes in excess of 0.5 saurus texana, Masticophis bilinea tus, the presence of these species on these m (1.5 ft), that were not readily and Diadophis punctatus, also may sites. caught in pit-fall traps, although a persist on riparian habitats within The presence of surface water also small percentage of arrays captured a deserts because of the high moisture has a profound affect on the distribu- few large snakes; these snakes were regime associated with surface litter, tion and abundance of certain species feeding on small rodents at the bot- higher humidity, and surface water within the study area. Kinosternon tom of traps. Therefore, the paucity (Jones and Glinski 1985). sonoriense, Trionyx spiniferus, Thamno- of large snakes on samples sites A similar relationship appears to phis cyrtopsis, Bufo alvarius, Bufu mi- within habitats probably reflects the exist in desert habitats occupied by croscaphus, Bufo woodhousei, Rana pipi- ability of larger snakes to escape Xantusia vigilis. This lizard also has a ens, Rana catesbeiana, Hyla urenicolor, from pit-fall traps rather than the dis- low preferred body temperature, and and Ambystoma tigrinurn occur only tribution and abundance of mi- it only occurs on Mojave Desert sites on sites with permanent water crohabi tats within habitat types. Ad- occupied by agaves (Agave spp.) and (springs, creeks, rivers, dirt tanks). ditionally, amphibians and reptiles yuccas (Yucca spp. and Nolina spp.); All of these species are restricted to with restricted activity patterns (e.g., these plants create cool, moist mi- permanently watered sites because of toads) or home ranges (Xantusia vig- crohabitats within desert habitats. In a combination of physiological ilis) also were rarely trapped and, the southern part of its range, X. wig- (Walker and Whitford 1WO), mor- therefore, verified on few sites within ilis only occupies Sonoran Desert on phological (Mayhew 1968), reproduc- a habitat. The limited number of steep slopes in mountain canyons, or tive (Justus et al. 1977), or behavioral mixed broadleaf and chaparral array on top of mountains (> 1220 rn or (Hulse 1974) limitations. In addition sites with Gerrhonotus kin@ probably 4000 ft) in chaparral habitats. This to occurring near permanent water, reflect a low sampling effort in these shift in habitat association may re- Bufo punctatus also occurs in rock- habitats during the fall; this lizard's flect increased average temperature bound canyons with intermittent wa- peak activity is during its breeding and aridity associated with decreas- ter, and Bufo cognatus, B. debilis, B. season in the fall (Robert Bowker ing latitude; canyons and mountain retiformis, and Gastrophyrne olivacea personal cornm.). summits may be the only sites mod- occur on sites with clay and clay- erate enough to support this lizard. loam soils that accumulate surface A similar moisture or temperature water during summer convectional Habitat Conditions relationship may also account for dif- rainstorms. All of these species pos- ferences observed in habitat type as- sess adaptations, such as a rapidly The condition of habitats may play sociations of Tantilla hobarfsrnithii, developing embryo, that are condu- an important role in determining the Cophosaurus texana, and Diadophis cive to survival in areas with inter- distribution and abundance of am- punctatus in the eastern and western mittent surface water (Creusere and phibians and reptiles. In Arizona, the portions of their ranges. In the west- Whitford 31976). large variety of land uses within the ern portion of the study area, these A number of species were verified area may affects the distribution and reptiles occur only in chaparral or on fewer than half of the array sites abundance of certain microhabitats riparian habitat types (excluding within habitat types. These low per- and may account for variation in spe- mixed riparian scrub habitats). In the centages may reflect speciesf associa- cies composition within habitats. A eastern and southeastern portions of tion with specific microhabitats and number of studies have shown the the study area, these species also oc- the abundance and distribution of effects of land uses on amphibians cur in the Sonoran Desert habitat microhabi tats within habitat types. and reptiles and their habitats. These type. Eastern and southeastern Sono- For example, Chilomeniscus cinctus include grazing (Bury and Busack 1974, Jones 1981a, Szaro et. a1 1985), 1979). Simovich (1979) showed that major drainages. Water impound- off-road vehicle use (Bury et al. 1977, fire set back succession within chap- ment and diversion-associated Bury 19801, forest management (Ben- arral habitats (grass/ forb succes- changes in aquatic habitats from per- nett et al. 1980), and stream modifi- sional stage), and that these changes manent riffles and runs to pools may cation resulting from water im- resulted in increases in certain spe- have caused the immigration of B. poundmen ts (Jones, this volume). cies and decreases in others. As suc- woodhousei into areas formerly occu- Generally, these affect habitat struc- cession proceeded to shrubs and pied by only B. rnicroscaphus (Brian ture. For example, excessive, long- trees, reptiles that were abundant in Sullivan personal comm.). term livestock grazing reduces the the grass/ forb successional stage There is considerable taxonomic abundance and diversity of forbs and (eg., Ph ynosoma corona turn) became confusion about a population of perennial grasses. Many former des- less abundant, and others that pre- Kinosternon sonoriense on the Big ert grassland habitats are now domi- ferred wooded sites (e.g., Sceloporus Sandy River near Wi kieup. Because nated by shrubs such as creosotebush occidentalis) became more abundant. specimens with raised 9th marginal (Lavvea tridentata) and mesquite scales had been taken from this area, (Prosopis glandulosa) (York and Dick- Stebbins (1966) considered this popu- Peddie 1969). Jones (1981a) showed Historical vs. Present Distributions lation to be Kinosternon flavescens, but large differences in the presence and Iverson (1978) considered it to be K. abundance of certain lizards on heav- Prior to this study, records of am- sonoriense, based on specimens with- ily vs. lightly grazed sites, especially phibians and reptiles on the study out 9th marginals. Of the 12 indi- on riparian, desert grassland, and area were limited; one of the primary viduals observed during this study, 6 woodland habitats, attributable to reasons for which this study was had raised 9 th marginals and 6 did differences in lizard ecology and dif- conducted was to assemble basic dis- not. Based on its large separation ferences in habitat structure between tribution information. Therefore, from the nearest population of K. heavily vs. lightly grazed areas. Cer- range expansions or reductions were flavescens, Iverson (personal comm.) tain lizards, such as Cnemidophorus hard to document. This study re- considers this population to be an tigris, prefer open, shrubby sites; sulted in range extensions of ap- aberrant form of K. sonoriense. these lizards are more abundant on proximately 35 species, and clarified heavily grazed sites where shrubs the relationship of Arizona habitats have replaced grasses and forbs to habitats in adjacent geographic (Jones 1981a). Conversely, certain regions. Many species, such as Helod- Similarity of Habitats Types lizards, such as Eumeces gilberti, pre- erma suspecturn, E umeces gilberti, Sce- fer grassy, moist sites, and are, there- loporus clarki, Tantilla hobarfsrnithii, It is possible to discern definite pat- fore, less abundant on or absent from and parthenogenic whiptail lizards terns in the diversity of and similari- sites where grazing has reduced tree (Cnemidophorus flagellicaudus, C. uni- ties between the herpetofaunas of reproduction (eg., cottonwoods, parens, and C. velox) proved to be different habitat types within the Populus fremontii on riparian sites) or considerably more widespread than study area. There is an apparent ele- suppressed grasses (e& on desert previous records indicated-not sur- vational gradient affecting species grassland sites) (Jones 1981a). prising since many areas had never diversity. Desert habitats between The reduction of naturally-occur- been intensively sampled. The expan- 610 and 1067 m (2000-3500 ft), ripar- ring water and the modification of sion of E. gilberti's range results from ian habitats between 549 and 1220 m river and stream habitats has been the discovery of the California (1800-4000 ft), and chaparral habitats shown to affect the composition of subspecies, E. g. rubricaudatus, in between 1067 and 1525 m (3500-5000 amphibians and reptiles within habi- chaparral and pinyon-juniper habi- ft) had greater species richness than tats, especially riparian sites (Jones tats; the distribution of E. g, ari- higher elevation woodland (> 1677 m 1988). Platz (1984) attributes the ex- zonenis is limited to a cottonwood- or 5500 ft, e.g., Ponderosa pine) and tinction of Rana onca to modification willow riparian habitat along an 18 desert habitats (> 1220 m or 4000 ft, of stream habitats along the Virgin km (11 mi) stretch of the Has- eg., sagebrush). Additionally, low River. Species that prefer lentic or sayampa River immediately south of elevation desert habitats (> 610 m or pool habitats should increase on sites Wickenburg (see Jones et al. 1985, 2000 ft, e.g., creosotebush), had rela- with water impoundments, whereas Jones and Glinski 1985). tively low species diversity. Higher species that prefer lotic or running Only one species demonstrated a species diversity on middle elevation water should decrease. range reduction. Pure populations of habitat types may reflect these habi- Natural phenomena, such as fire, Bufo microscaphus have apparently tats' moderate environmental and also affect species composition been reduced due to hybridization climatic conditions, whereas higher within habitats (Kahn 1960, Simovich with Bufo woodhousei, especially on and lower elevation habitats possess extreme environmental and climatic portant sources of food and cover from California chaparral suggest conditions (e.g., temperature). For (Ohmart and Anderson 1986). Simi- that these species evolved after Pleis- example, low elevation creosotebush larities between chaparral and desert tocene glaciation. habitats have sparse canopies, and habitat types, such as Mohave Des- There were a few inconsistencies temperatures often exceed 60 C near ert, Sonoran Desert, and mixed ripar- in the results of the two analyses the surface in summer (Oosting ian scrub, result from occurrence of used to determine similarity between 1956). High elevation sites are cold typical desert species (e.g., Callisau- habitats (the cluster analysis of all and are often snowcovered until late rus draconoides) on upland sites rather data vs. the cluster analysis of only April so that the growing season is than the occurrence of upland spe- array data). These inconsistences par- short. A1 though possessing relatively cies (e.g., E. gilberti) on desert sites. tially result from the inconsistency of low species richness, low elevation The diversity of and similarities arrays to capture turtles and medium creosotebush habitats are more di- among amphibian and reptile com- and large-sized snakes, and partially verse than high elevation sites. These munities of habitat types also may from the analyses themselves (see the differences in diversity may reflect have been affected by the proximity Methods Section for a more detailed thermal conditions at these eleva- of habitat types to evolutionary cen- explanation). tional extremes. Many of the species ters. Because of the many new rec- that occur within creosotebush are ords for herpetofauna generated by nocturnal, and, therefore, these ani- this study, we now have a better pic- Conclusions and mals avoid exposure to extreme sur- ture of the sources of diversity for Recommendations face heat. On higher elevation habi- this area. Many of the amphibians tats, the problem is not avoiding heat and reptiles occurring in the Sonoran This survey indicates that most spe- but, rather, gaining heat for activity. and Mohave Deserts evolved in Baja cies present within western Arizona Other than along rock outcrops, California and along the western sec- are widespread, and that few war- rapid heating is difficult for reptiles tion of mainland Mexico; these areas rant special management considera- at higher elevations. Differences be- were linked until their separation 13 tion. However, it is evident that cer- tween diversity and species composi- million years ago (Murphy 1983). tain species are more vulnerable to tion on medium elevation habitat With the retreat of pleistocene glacia- range or population reduction than types probably reflect differences in tion and spread of xerophyllous and others. Generally, these species are microhabitat abundance and diver- desert habitats, amphibians and rep- those that require microhabitats that sity on habitat types (see earlier dis- tiles moved northward into southern are easily affected by land uses. cussion on microhabitats). Lack of California and southwestern Ari- It appears that habitat moisture diversity on disclimax desert grass- zona; hence, Sonoran and Mohave and moderated surface temperatures land sites probably reflects the lack Desert habitat types have similar her- are of primary importance to many of vegetation structure on these sites. petofaunas. Although many species species in western Arizona. Downed There was similarity in the herpe- immigrated into what is today the and dead surface litter (debris), such tofaunas of certain habitat types. All Sonoran and Mohave Deserts, only a as logs and leaves, play a major role desert habitats, except sagebrush, few species immigrated as far north in moderating surface temperature had very similar herpetofaunas, as as the Great Basin Desert. Higher ele- and enhancing moisture (Dauben- did most moderate elevation habitats vations may have precluded many of mire 1974). Horizontal and vertical (e.g., chaparral, pinyon-juniper, and these species from colonizing the vegetation structure also help moder- mixed riparian scrub). This is pre- Great Basin desert habitat types and, ate temperatures and increase mois- dictable because all of these habitats hence, it's herpetofauna is different ture. In developing management occur in close proximity and are from and less rich than those of the schemes, priority should be given to structurally similar. There was a other two deserts. maintaining or enhancing surface lit- moderate degree of similarity be- The discovery of the subspecies ter and vegetation structure. It is im- tween cottonwood-willow riparian Eurneces gilberti rubricatidatus, for- portant to maintain tree reproduc- and desert habitats, chaparral and merly unknown in Arizona, suggests tion, and to leave litter on the surface cottonwood-willow riparian, and that Arizona chaparral was closely rather than piling and burning it. The chaparral and desert habitats. Be- associated with California chaparral latter practice is especially important cause cottonwood-willow riparian during Pleistocene glaciation; E. g. on cottonwood-willow riparian sites habitats traverse through both desert rubricaudatus evolved in California within deserts, since many species in habitats and upland habitats, many sclerophyll woodland (Taylor 1935). riparian sites are totally dependent of the species associated with the That parthenogenic whiptail lizards, on surface litter for their survival surrounding habitats also frequent such as Cnemidophorus flagellicaudis, (Jones and Glinski 1985). Many ripar- riparian sites; riparian sites are im- C. uniparens, and C. velox, are absent ian sites within the study area have reduced amounts of trees and sur- termining the extent of hybridization Special thanks to W.L. Minckley and face litter, principally because live- between the toads B. microscaphus M.J. Fouquette for technical contribu- stock have greatly reduced the repro- and Bufo woodhousei. Pure populations to this project's study design, duction of cottonwood trees by re- tions of B. microscaphus should be lo- and to the Bureau of Land Manage- ducing the survival of seedlings cated and protected against hybridi- ment's line managers and supervi- (Jones 1981a). Management prescrip- zation with B. woodhousei. If only a sors, Bill Barker, Roger Taylor, Barry tions are needed on these sites to in- few pure populations are found, the Stallings, Dean Durfee, Gary crease the survivorship of seedling Arizona Game and Fish Department McVicker, and Malcolm Schnitkner, and young cottonwood trees. and/or the U.S. Fish and Wildlife for their continuous support of re- Populations of "upland" species Service should set up a captive source inventories on public lands. I (eg., Eumeces gilberti) on habitat is- breeding program to reduce this thank John Fay, Scott Belfit, R. Bruce lands are more vulnerable to impacts toad's risk of extinction. Bury, and Robert Szaro for review of associated with certain land uses Although I obtained distributional this manuscript. Finally, all of us than populations occurring on major, records of Gopherus agassizii, Burge who strive for the conservation of continuous stands. Jones et al. (1985) (1979,1980) and Schneider (1980) nongame wildlife on public lands are described these habitat islands, some provide considerably more detail on indebted to Gary McVicker, Bill only 10 ha (25 acres) in size. Loss or the needs of this species. However, McMahan, and Don Seibert for their fragmentation of any portion of these many biologists consider G. agassizii tireless efforts in getting top-level islands could result in the local extir- to be declining throughout most of management to support nongame pation of one or several upland spe- its range. The U.S. Fish and Wildlife programs. cies (see Bury and Luckenbach 1983 Service (1987) continues to list G. and Harris 1984 for the effects of agassizii as a species that needs fur- habitat fragmentation and habitat ther study to determine its status, LITERATURE CITED loss on species occurring on habitat although it has determined that the islands). Because even small modifi- Federal listing of the tortoise Bennett, Stephen H., J. Whitfield Gib- cations to island habitats can result in throughout its range is warranted bons, and Jill Glanville. 1980. Ter- the extirpation of upland species, but precluded by species needing restrial activity, abundance, and proposed projects should be moved more immediate listing (eg., species diversity of amphibians in differ- to alternative sites whenever pos- in more eminent danger of extinc- ently managed forest types. sible; mitigation strategies should be tions). The BLM should continue to American Midland Naturalist used only as a last resort. Top prior- give high priority to the study and 103:412-416. ity should be given to protecting management of this species in Ari- Brown, David E. 1978. The vegeta- these sites in land-use and on-the- zona. tion and occurrence of chaparral ground activity plans (see Jones et al. If the few measures suggested in and woodland flora on isolated 1985 for specific locations of these this paper are implemented, western mountains within the Sonoran and sites). Arizona should continue to support Mohave Deserts in Arizona. Jour- Although all amphibians in the one of North America's most diverse nal of Arizona Academy Sciences study area (excluding Bufo mi- herpetofaunas. 13:l-12. croscaphus) appear to be stable, water Brown, David E., Charles H. Lowe, in many habitats continues to be de- and Charles P. Pase. 1979. A digit- veloped. In addition, new informa- ACKNOWLEDGMENTS ized classification system for the tion (Bruce Bury personal comm, biotic communities of North Corn and Fogleman 1984) suggest I am indebted to several people for America, with community (series) that several populations of ranid the completion of this project. Don and association examples from the frogs have been extirpated from Seibert, Bob Furlow, and Ted Cor- Southwest. Journal of Arizona western North America, although dery were instrumental in obtaining Academy of Science 14, Suppl. 1, there is no apparent cause for their funding, equipment, and personnel p. 16. extirpation. Considering the heavy for this study. Lauren Kepner, Tim Burge, Betty L. 1979. A survey of the use of spring and creek water, and Buse, Dan Abbas, Terry Bergstedt, present distribution of the desert the reported loss of many ranid Kelly Bothwell, William Kepner, tortoise (Gopherus agassizii) in Ari- populations in the West, high prior- Dave Shaffer, Bob Hall, Ted Cordery, zona. U.S. Bureau of Land Man- ity should be given to monitoring Scott Belfit, Ted Allen, Ken Relyea, agement, Denver, Colorado. Con- amphibian populations at springs Becky Peck, Brian Millsap, Jim Zook, tra~t No. YA-512-CTB-108. and creeks in Arizona. Additionally, Jim Harrison, and Greg Watts helped Burge, Betty L. 1980. Survey of the high priority should be given to de- collect both animal and habitat data. present distribution of the desert tortoise, Gopherus agassizii, in Ari- J. Scott (ed.), Herpetological com- in the American Southwest. zona. U.S. Bureau of Land Man- munities, U.S. Fish and Wildlife Copeia 1978:476-479. agement, Denver, Colorado. Con- Service, Wildlife Research Report Jones, K. Bruce. 1981a. Effects of tract No. YA-512-CT8-108. Number 13. grazing on lizard abundance and Bury, R. Bruce. 1980. What we know Case, Thomas J. 1983. The reptiles: diversity in western Arizona. and do not know about off-road ecology. In T.J. Case and M.L. Southwestern Naturalist 26(2):107- vehicle impact on wildlife. In R.N. Cody (eds.), Island biogeography 115. Andrews and P.F. Nowah (eds.), in the Sea of Cortez. University of Jones, Kenneth Bruce. 1981b. Distri- Off-road vehicle use: a manage- California Press, Berkeley. bu tion, ecology, and habitat man- ment challenge. U.S.D.A. Office of Connor, Edward F. and Daniel Sim- agement of the reptiles and am- Environmental Quality, 748 p. berloff. 1979. The assembly of spe- phibians of the Hualapai-Aquarius Bury, R. Bruce and Stephen D. cies communities: chance or com- planning areas, Mohave and Busack. 1974. Some effects of off- petition? Ecology 6O:ll32-ll4O. Yavapai Counties, Arizona. U.S. road vehicles and sheep grazing Corn, Paul Stephan and James C. Bureau of Land Manage. Technical on lizard populations in the Fogleman. 1984. Extinction of Note No. 353, Denver, Colo. Mojave Desert. Biological Conser- montane populations of the north- Jones, K. Bruce. 1987. Amphibians vation 6:179-183. Bury, R. Bruce, ern leopard frog (Rampipiens) in and reptiles. p. 267-290. In A.Y. Roger A. Luckenbach, and Colorado. Journal of Herpetology Cooperrider, R.J. Boyd, and H.R. Stephen D. Busack. 1977. Effects of 18:147-152. Stuart (eds.), Inventory and moni- off-road vehicles on vertebrates in Creusere, F. Michael and Walter G. toring of wildlife habitat. US. Bu- the California Desert. U.S. Fish Whitford. 1976. Ecological rela- reau of Land Management, Den- and Wildlife Service Wildlife Re- tionships in a desert anuran com- ver, Colorado xviii, 858 p. search Report No. 8. munity. Herpetologica 32:7-18. Jones, K. Bruce., Dan R. Abbas, and Bury, R. Bruce and M.G. Raphael. Daubenmire, Rexford F. 1974. Plants Terry A. Bergstedt. 1981. Herpeto- 1983. Inventory methods for am- and environment: a textbook of logical records from central and phibians and rep tiles. Proceedings autecology. John Wiley and Sons, northwestern Arizona. Herpeto- of the International Conference on New York, New York. 3rd Ed. logical Review 12(1):I 6. Renewable Resources, Inventories Fitch, Henry S. 1955. Habits and ad- Jones, K. Bruce and Patricia C. for monitoring changes and aptations of the Great Plains skink Glinski. 1985. Microhabitats of liz- trends. Oregon State University, (Eumeces obso2etus). Ecological ards in a southwestern riparian Corvallis. Monographs 25(3):59-83. community. p. 355-358. In R. Roy Bury, R. Bruce and Roger A. Lucken- Fleharty, Eugene D. 1967. Compara- Johnson et. al., Riparian ecosys- bach. 1983. Vehicular recreation in tive ecology of Thamnuphis elegans, tems and their management: rec- arid lands drives: biotic responses Tharnnophis cyrtopsis, and Thamno- onciling conflicting uses. First and management alternatives. p. phis rufipunctatus in New Mexico. North American riparian confer- 217-221. In R.H. Webb and H.G. Southwestern Naturalist 12(3):207- ence. Rocky Mountain Forest and Wilshire (eds.), Environmental ef- 230. Range Experimental Station, Gen- fects of off-road vehicles: impacts Hair, Jay D. 1980. Measurements of eral Technical Report Number and management in arid regions. ecological diversity. p. 269-275. In RM-120., Fort Collins, Colo. Springer-Verlag, New York, New S.D. Schemnitz (ed.), Wildlife Jones, K. Bruce, Lauren P. Kepner, York. Management Techniques Manual. and William G. Kepner. 1983. Buse, Timothy C. 1981. Distribution, The Wildlife Society, Washington, Anurans of Vekol Valley, central ecology, and habitat management D.C. Arizona. Southwestern Naturalist of the reptiles and amphibians of Harris, Larry D. 1984. Island biogeo- 28(4):469-470. the Cerbat planning unit, Mohave graphy applied: old growth is- Jones, K. Bruce, Lauren P. Kepner, County, Arizona. U.S. Bureau of lands and wildlife conservation in and Thomas E. Martin. 1985. Spe- Land Management, Kingman, Ari- the western Cascades. University cies of reptiles occupying habitat zona. Unpubl. Man. of Chicago Press, Chicago, Illinois. islands in western Arizona: a de- Buse, Timothy C. 1983. Herpetologi- Hulse, Arthur C. 1974. An autecol- terministic assemblage. Oecologia cal records from northwestern ogy study of Kinosternon sonoriense 66:595-601. Arizona. Herpetol. Rev. 14:53-54. Ieconte (Chelonia: Kinosternidae). Jones, K. Bruce, Lauren M. Porzer, Campbell, Howard W. and Stephen Phd. Dissertation, Arizona State and Kelly J. Bothwell. 1982. Her- P. Christman. 1982. Field tech- University, Tempe. petological records from westcen- niques for herpetofaunal commu- Iverson, John. 1978. Distributional tral Arizona. Herpetological Re- nity analysis. p. 193-209. In Norm problems of the genus Kinosternon view. 13(2):54. Justus, J. T., Mark Sandomir, Tom tonianus group. University of in southern New Mexico during Urquhart, and Barbara Orgel California Publications in Zoology the past hundred years. p. 157-166. Evan. 1977. Developmental rates 48(4):169-220. In W.G. McGinnes and B.J. of two species of toads from the Schneider, Paul B. 1980. A popula- Goldman (eds.), Arid lands in per- desert Southwest. Copeia tion analysis of the desert tortoise spective. University of Arizona 1977:592-594. in Arizona during 1980. U.S. Bu- Press, Tucson. Kahn, Walter C. 1960. Observations reau of Land Management, Phoe- Zweifel, Richard G. and Charles H. on the effect of a burn on a popu- nix, Arizona. Contract No. AZ- Lowe. 1966. The ecology of a lation of Sceloporus occidentalis. 950-279-0014. population of Xantusia vigilis, the Ecology 41(2):358-359. Simovich, Marie A. 1979. Post fire desert night lizard. American Mu- Mayhew, William W. 1968. Biology reptile succession. Cal-Neva seum Novitates 2247:l-57. of desert amphibians and reptiles. 1979:104-113. p. 195-356. In G.W. Brown, Jr. Stebbins, Robert C. 1966. A field (ed.), Desert biology. Academic guide to western reptiles and am- Press, New York, New York. phibians. Houghton Mifflin Co., Murphy, Robert W. 1983. Paleobio- Boston, 1st Edition. geography and genetic differentia- Stebbins, Robert C. 1985. A field tion of the Baja California herpe- guide to western reptiles and am- tofauna. Occasional Papers Cali- phibians. Houghton Mifflin Co., fornia Academic Sciences 137:l-48. Boston, 2nd Edition. Norris, Kenneth S. 1953. The ecology Szaro, Robert C., Scott C. Belfit, and of the desert iguana, Dipsosaurus J. Kevin Aitkin. 1985. Impact of dorsalis. Ecology 34:265-287. grazing on a riparian garter snake. Ohmart, Robert D. and Bertin W. p. 359-363. In R. Roy Johnson et. Anderson. 1987. Riparian habitats. al., Riparian ecosystems and their p. 169-200. In A.Y. Cooperrider, management: reconciling conflict- R. J. Boyd, and H.R. Stuart (eds.), ing uses. First North American Inventory and monitoring of wild- riparian conference. Rocky Moun- life habitat. U.S. Bureau of Land tain Forest and Range Experimen- Management, Denver, Colorado tal Station, General Technical Re- xviii, 858 p. port Number RM-120., Fort Oosting, Henry J. 1956. The study of Collins, Colorado. plant communities. W.H. Freeman Taylor, Edward H. 1935. A taxo- and Company, San Franciso, Cali- nomic study of the cosmopolitan fornia. scincoid lizards of the genus Pianka, Eric R. 1966. Convexity, des- Eumeces with an account of the ert lizards, and spatial heterogene- distributions and relationships of ity. Ecology 47:1055-1059. its species. University of Kansas Pianka, Eric R. and William S. Science Bulletin 23:1-643. Parker. 1972. Ecology of the igua- U.S. Fish and Wildlife Service. 1987. nid lizard, Callisaurus draconoides. Notice of findings on petitions and Copeia 1972493-508. initiation of status review. Federal Pimental, Richard A. 1979. Mor- Register 52(126):24485-24488. phometrics: the multivariate Van Devender, Thomas R. and Wil- analysis of biological data. Ken- liam G. Spaulding. 1977. Develop- dall/Hunt Publishing Company, ment of vegetation and climate in Dubuque, Iowa. the southwestern United States. Platz, John E. 1984. Status report for Science 204701-710. Ram onca Cope. Status report pre- Walker, Robert F. and Walter G. pared for the U.S. Fish and Wild- Whitford. 1970. Soil water absorp- life Service, Albuquerque, New tion capabilities in selected species Mexico. 28 p. of anurans. Herpetologica Rogers, Thomas L. and Henry S. 26(4):411-416. Fitch. 1947. Variation in the skinks York, John C. and William A. Dick- (Reptilia: Lacertilia) of the skil- Peddie. 1969. Vegetation changes