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Two new Centrolenella are described, C. azulae from the Cordillera Azul of Perú, and C. puyoensis from the Amazonian slopes of the Ecuadorian Andes. Centrolenella azulae is distinguished by its moderately large size, the presence of vomerine teeth, a snout truncate in dorsal view and slightly protruding in profile, a color pattern in preservative of very diffuse lavender with small colorless spots, basal webbing on the outer fingers, and a low ulnar fold. Centrolenella puyoensis is distinguished by its moderately large size, a snout truncate in dorsal view and rounded in profile, a color pattern in preservative of purplish-gray with large cream spots, a tympanum that is three-fourths exposed, and intricate anal...
Categories: Publication; Types: Citation; Tags: Herpetologica
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Habitat modeling offers an approach to understanding some management problems of desert tortoises (Gopherus agassizii) and to focusing new research efforts. Modeling can provide (1) a method to organize existing information, (2) a means to identify whether physical habitat or some factor outside the scope of the habitat model is limiting populations, (3) a method to integrate habitat into resource development planning, and (4) a mechanism for focusing research on missing species-habitat information.
Categories: Publication; Types: Citation; Tags: Herpetologica
A population estimate of whipsnakes, Masticophis t. taeniatus, utilizing communal hibernacula at Lone Rock, Tooele County, Utah, was made by taking samples in autumn 1973 and in spring 1974. The number of whipsnakes using this site was estimated by various methods to be 425-543. Confidence limits for the Lincoln Index were 276-618. Estimates of postdispersal density ranged from 0.15-0.22 whipsnake/ha and 17.7-26 g/ha. Whipsnakes used at least three separate dens at this location, differing from other sites where only one den per den complex is used. Age structure appeared equally balanced among various age groups older than 1 year old, and the latter was underrepresented. Sex ratios were significantly biased toward...
The hominga bilityo f deserti guanas,D ipsosauruds orsalisw, as studiedi n Anza Borrego Desert State Park, San Diego County, and in Thousand Palms, Riverside County, California. Eighty-three lizards were displaced distances ranging from 50-400 m. Twenty-two lizards successfully homed at least once. Two lizards homed from distances of 250 m, and one lizard from 274 m. These homing distances exceed the previously reported maximum homing distance for lizards. Similarities between the results of this study and previous studies are discussed. Published in Herpetologica, volume 33, issue 1, on pages 123 - 127, in 1977.
Categories: Publication; Types: Citation, Journal Citation; Tags: Herpetologica
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Fundamental issues in the study of predator-prey interactions include addressing how prey coexist with their predators and, moreover, whether predators promote coexistence among competing prey. We conducted a series of laboratory experiments with a freshwater assemblage consisting of two predators that differed in their foraging modes (a crayfish, Procambarus sp., and the western mosquitofish, Gambusia affinis) and their prospective anuran prey (tadpoles of the narrow-mouthed toad, Gastrophryne carolinensis, and the squirrel treefrog, Hyla squirella). We examined whether competition occurs within and between these two prey species and, if so, whether the non-lethal presence of predators alters the outcome of competitive...
Categories: Publication; Types: Citation; Tags: Herpetologica
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We monitored 11 populations of eight species of Eleutherodactylus in Puerto Rico from 1989 through 2001. We determined relative abundance of active frogs along transects established in the Caribbean National Forest (El Yunque), Carite Forest, San Lorenzo, and in the vicinity of San Juan. Three species (Eleutherodactylus karlschmidti, E. jasperi, and E. eneidae) are presumed to be extinct and eight populations of six different species of endemic Eleutherodactylus are significantly declining at elevations above 400 m. Of the many suspected causes of amphibian declines around the world, we focused on climate change and disease. Temperature and precipitation data from 1970a??2000 were analyzed to determine the general...
Categories: Publication; Types: Citation; Tags: Herpetologica
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Desmognathus fuscus and Desmognathus ochrophaeus mere studied over a 6-wk period by mark-recapture and removal methods. Density is ~. 0.8/m2 in D. fuscus and 0.6 - l.l/m2 in D. ochrophaeus; respective biomass densities are 1.5 and 1.0 g/m2. Adjusted estimates indicate a greater proportion of adults in D. ochrophaeus. The observed sex ratio is unbalanced in favor of males but may be close to 1:1 in each species. Adult male age structures based on testis lobes indicate greater adult survivorship in D. ochrophaeus than D. fuscus. Local populations of D. ochrophaeus may differ from others studied in having a shortened larval period. Indirect evidence may indicate greater predation on D. fuscus than on D. ochrophaeus....
Categories: Publication; Types: Citation; Tags: Herpetologica
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We describe a new species of Hyla that differs from the similar-loohng species H. pentheter by reaching a larger size, ha\iing a smaller tympanum, more webbing on the feet, more extensive nuptial excrescences, and a different color pattern on the flanks. \Ve tentatively place this new species in the phenetic assemblage commonly referred to as the H. bistincta group. \Ve describe and illlistrate the tadpole and discuss ontogenetic variation among tadpoles, with reference to existing information on tadpoles of other species from the H. bistincta group.
Categories: Publication; Types: Citation; Tags: Herpetologica
Home range size of adult desert iguana lizards, Dipsosaurus dorsalis, was studied during June and July of 1975, in Thousand Palms, Riverside County, California, USA. The mean home range size of S 8 (1,462 m') and 9 9 (1,558 m') for combined pre-storm and post-storm sightings was not significantly different. Home range size was correlated positively with body size and the number of sightings. A 5-day sandstorm occurred 16-21 June which greatly reduced the leaves and flowers of native plants in the study area. Home range size and overlap prior to and after the storm were compared. Home range size of 12 lizards, with four or more observations each for the two periods, was significantly larger after the storm. Home...
Categories: Publication; Types: Citation, Journal Citation; Tags: Herpetologica
Aggregation of Coleonyx variegatus in diurnal shelter sites is shown to be a statistically valid phenomenon, confirming earlier reports based on subjective impressions. Preliminary data on causative factors suggest that limited burrow availability promotes aggregation. Experiments in which two individuals were placed in cages having an excess of burrows revealed no indication of interindividual attraction. However, these results do not exclude the operation of social factors in aggregation. On the contrary, pilot data provide hints that the sexes may differ in aggregative behavior. We hypothesize that lizard density, sex, and physical variables such as temperature and moisture may be associated with joint burrow...
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Understanding the relationship between climate-driven habitat conditions and survival is key to preserving biodiversity in the face of rapid climate change. Hydroperiod—the length of time water is in a wetland—is a critical limiting habitat variable for amphibians as larvae must metamorphose before ponds dry. Changes in precipitation and temperature patterns are affecting hydroperiod globally, but the impact of these changes on amphibian persistence is poorly understood. We studied the responses of Boreal Chorus Frog (Pseudacris maculata) tadpoles to simulated hydroperiods (i.e., water level reductions) in the laboratory using individuals collected from ponds spanning a range of natural hydroperiods (Colorado Front...
Categories: Publication; Types: Citation; Tags: Herpetologica
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A critical variable in both ecological and conservation field studies is determining how many individuals of a species are present within a defined sampling area. Labor intensive techniques such as capture-mark-recapture and removal sampling may provide estimates of abundance, but there are many logistical constraints to their widespread application. Many studies on terrestrial and aquatic salamanders use counts as an index of abundance, assuming that detection remains constant while sampling. If this constancy is violated, determination of detection probabilities is critical to the accurate estimation of abundance. Recently, a model was developed that provides a statistical approach that allows abundance and detection...
Categories: Publication; Types: Citation; Tags: Herpetologica
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We examined 63 specimens of Coluber constrictor from Colorado and Utah using eight external morphological characters that have been used to distinguish C. c. mormon from C. c. flaviventris. We grouped the snakes into three Operational Taxonomic Units (OTU's) in a transect across the Rocky Mountains: the eastern Front Range foothills in Colorado; the inter-mountain region (western slope of Colorado and northeastern Utah); and the western foothills of the Wasatch Mountains in Utah. Statistically significant variation among the OTU's was discovered for ration of tail length to total length, number of central and subcaudal scales, and number of dentary teeth. However, variation is clinal with nearly complete overlap...
Categories: Publication; Types: Citation; Tags: Herpetologica
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Barking frogs (Eleutherodactylus augusti) are distributed from southern Mexico along the Sierra Madre Occidental into Arizona and the Sierra Madre Oriental into Texas and New Mexico. Barking frogs in Arizona and most of Texas live in rocky areas in oak woodland, while those in New Mexico and far western Texas live in rodent burrows in desertscrub. Barking frogs in each of the three states have distinct coloration and differ in sexually dimorphic characters, female vocalization, and skin toxicity. We analyzed advertisement call variation and conducted a phylogenetic analysis using mitochondrial DNA sequences (ND2 and tRNA regions) for barking frogs from these three states. Advertisement calls of frogs from Arizona...
Categories: Publication; Types: Citation; Tags: Herpetologica


map background search result map search result map Morphological variation and zoogeography of racers (<i>Coluber constrictor</i>) in the central Rocky Mountains Morphological variation and zoogeography of racers (<i>Coluber constrictor</i>) in the central Rocky Mountains