Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Herpetologica”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

68 records · Page 4Linked to original sources
USGS1951

Distinctions between the snake genera Contia and Eirenis

Summary: Various workers have believed Contia to be related to or congeneric with either or both Sonora and Eirenis, the latter a genus of Western Asia. Study of hemipenes, teeth, and jaws indicates that these genera are not related to one another. The hemipenes of Eirenis modesta and Contia tenuis are described. Eirenis is thought to be a derivative of the racer group. Relationships of Contia are unknown. It is suggested that some North American genera with xenodontine-type hemipenes may not be of the South American faunal element and may have been in North America at least as long as the Old Northerners.

Herpetologica↗
USGS1977

A population analysis of two species of streamside salamanders, genus Desmognathus

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. Fecundity is positively correlated with the size of females in both species and the slopes of the regression lines are similar. Mean egg complements are 21.2 for D. fuscus and 15.6 for D. ochrophaeus. Most observations support the hypothesis that demographic differences are related to differences in degree of terrestrialism between the two species.

Herpetologica↗
USGS1982

Study of aggregative behavior of Rhinophrynus dorsalis tadpoles: design and analysis

We conducted experiments using the apparatus and design followed by Wassersug and Hessler (1971) and Wassersug (1973) to test the aggregative behavior of tadpoles of Rhinophrynus dorsalis in response to visual and olfactory stimuli. Results neither supported nor refuted the hypothesis that either stimulus is used as a mechanism for school formation. The exercise did lead to doubts about the experimental design. Some ambiguity resulted from the fact that the significance of the results depended upon the way in which the data were analyzed. Several alternative methods were considered. We also observed tadpoles reared in isolation to determine the effect of prior social conditioning on aggregative behavior. Isolates grew less than group-reared animals, were less active, and exhibited a strong avoidance reaction when subsequently exposed to conspecifics.

Herpetologica↗
USGS1984

Estimating prey size and number in crayfish-eating snakes, genus Regina

Snakes of the genus Regina feed almost exclusively on crayfish. The paired, symmetrical gastroliths of crayfish are not digested and are detectable from x-rays of the snake. Gastrolith length is directly proportional to carapace length and can be obtained from x-rays. Carapace length can be converted to kcal of ingested energy. Using these relationships and repeated captures of radio-telemetered Regina, estimates of food consumption and energy intake by freeliving snakes are feasible. New information on prey selectivity, feeding behavior, and predator-prey size relations in Regina grahami and R. septemvittata are presented and compared with similar data for other snakes.

Herpetologica↗
USGS1989

Two new species of South American Centrorlenella (Anura: Centrolenidae) related to C. Mariae

Two new Centrolenella are described, C. azulae from the Cordillera Azul of Peru, 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 ornamentation. Both new species are closely related to the Peruvian C. mariae, and together the three species form the C. mariae group, definable on a number of shared, derived characters. A hypothesis of relationships within the mariae group is presented, postulating puyoensis as the most primitive and azulae as the most derived of the trio.

Herpetologica↗
USGS1982

Sea turtle distribution along the boundary of the Gulf Stream current off eastern Florida

Aerial surveys, out to 222 km off the east coast of central Florida during August 1980, revealed that marine turtles were distributed in a narrow zone west of the Gulf Stream. Of 255 loggerhead turtles, Caretta caretta, only three were observed east of the western boundary of the Gulf Stream. Radiometric thermometry revealed that the waters occupied by most Caretta were markedly cooler than the nearby waters of the Gulf Stream. Of 18 leatherback turtles, Dermochelys coriacea, all were seen west of the Gulf Stream in waters less than 70 m in depth. Marine turtles off eastern Florida are confined seasonally to nearshore waters west of the Gulf Stream. The records of Dermochelys in nearshore waters are in contrast with a deep water oceanic ecology often hypothesized for this species.

Herpetologica↗
USGS1998

A new species of Bachia (Squamata: Gymnophthalmidae) with pleisomorphic limb morphology

We describe a new species of Bachia from the upper Rio Negro drainage of southeastern Colombia and southern Venezuela. The new taxon is diagnosed by a complement of phalanges that is unique among gymnophthalmid lizards and intermediate relative to other Bachia and closely related genera. Variation in limb osteology among the species of Bachia and close relatives is reported. We discuss the distribution of B. panoplia and the taxonomic status of B. flavescens.

Herpetologica↗
USGS2000

A new species of Hyla (Anura: Hylidae) from the Sierra Mixes, Oaxaca, Mexico, with comments on ontogenetic variation in the tadpoles

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.

Herpetologica↗
USGS2009

Response to the Point of View of Gregory B. Pauly, David M. Hillis, and David C. Cannatella, by the Anuran Subcommittee of the SSAR/HL/ASIH Scientific and Standard English Names List

The Point of View by Gregory Pauly, David Hillis, and David Cannatella misrepresents the motives and activities of the anuran subcommittee of the Scientific and Standard English Names Committee, contains a number of misleading statements, omits evidence and references to critical literature that have already rejected or superseded their positions, and cloaks the limitations of their nomenclatural approach in ambiguous language. Their Point of View is not about promoting transparency in the process of constructing the English Names list, assuring that its taxonomy is adequately reviewed, or promoting nomenclatural stability in any global sense. Rather, their Point of View focuses in large part on a single publication, The Amphibian Tree of Life , which is formally unrelated to the Standard English Names List , and promotes an approach to nomenclature mistakenly asserted by them to be compatible with both the International Code of Zoological Nomenclature and one of its competitors, the PhyloCode .

Herpetologica↗
USGS2004

Using counts to simultaneously estimate abundance and detection probabilities in a salamander community

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 to be estimated simultaneously from spatially and temporally replicated counts. We adapted this model to estimate these parameters for salamanders sampled over a six vear period in area-constrained plots in Great Smoky Mountains National Park. Estimates of salamander abundance varied among years, but annual changes in abundance did not vary uniformly among species. Except for one species, abundance estimates were not correlated with site covariates (elevation/soil and water pH, conductivity, air and water temperature). The uncertainty in the estimates was so large as to make correlations ineffectual in predicting which covariates might influence abundance. Detection probabilities also varied among species and sometimes among years for the six species examined. We found such a high degree of variation in our counts and in estimates of detection among species, sites, and years as to cast doubt upon the appropriateness of using count data to monitor population trends using a small number of area-constrained survey plots. Still, the model provided reasonable estimates of abundance that could make it useful in estimating population size from count surveys.

Herpetologica↗
USGS1986

Morphological variation and zoogeography of racers ( Coluber constrictor ) in the central Rocky Mountains

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 from one end f the transect to the other for each character, suggesting a wide zone of intergradiation in the inter-mountain region. We do not believe reported differences in reproductive parameters between Great Plains and Great Basin racers are sufficient grounds for recognition of species, because clutch size is both geographically variable and dependent on the environment. The distribution of C. constrictor is similar to that of other reptiles with transmontane distributions in the western United States, and we suggest two possible routes of dispersal across the Continental Divide in southwestern Wyoming. Thus, elevation of C. c. mormon to species status is not supported by morphological, reproductive, or zoogeographic evidence.

Colorado;Utah↗
USGS1986

The application of habitat modeling to the desert tortoise ( Gopherus agassizii )

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.

Herpetologica↗
USGS1989

Duration of immobility in salamanders, genus Plethodon (Caudata: Plethodontidae)

Immobility is a potentially important antipredator behavior in salamanders, especially for those posessing noxious skin secretions. The duration of immobility in 15 species of terrestrial salamanders ( Plethodon ) varied among species. Most salamanders (78.8%) became immobile when initially contacted under field conditions, and remained immobile from 1-180 s. Immobility duration was inversely correlated with substrate temperature and covaried with air temperature, but snout-vent level (SVL) had no effect on duration. Only immobility times of Plethodon shenandoah were significantly different from any other species. Substrate temperature, air temperature, SVL, and species accounted for only a small percentage of the variance ( r 2 =0.09). The degree of disturbance received during a predator-prey encounter is probably more important than the subtle effects of temperature and SVL in determining immobility duration.

Herpetologica↗
USGS1989

Two new species of South American Centrolenella (Anura: Centrolenidae) related to C. mariae

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 ornamentation. Both new species are closely related to the Peruvian C. mariae , and together the three species form the C. mariae group, definable on a number of shared, derived characters. A hypothesis of relationships within the mariae group is presented, postulating puyoensis as the most primitive and azulae as the most derived of the trio.

Herpetologica↗