A new terrestrial species of Pseudoeurycea is described from the mountains of the Mixteca region of Oaxaca. Compared with other members of the genus, the new species is relatively slender and short-legged. The background color of the dorsum of this species is dark gray with reddish-brown spots. The Mixteca region of Oaxaca has long been poorly explored biologically, and the knowledge of the distribution of its salamanders is scarce. Herein, we present new information regarding salamanders species in this region.

A new species of Ischnocnema is described from cloud forests in the Andes of northwestern Bolivia (La Paz Department). The new species can be distinguished from all other Ischnocnema except Ischnocnema sanctaecrucis by the presence of a pale sacral stripe from the level of the caudal tip of the coccyx to the level of the sacrum, well-developed occipital and sacral folds, rounded narrow terminal discs 1.3 times as wide as the corresponding phalange, and dorsal skin moderately warty. It can be distinguished from I. sanctaecrucis, also of the Bolivian cloud forests, by having head longer than wide, well-marked occipital and sacral folds, longer subacuminate to rounded snout, ventral regions mostly cream with little brown mottling, and dorsal region without reddish to scarlet mottling or spots. The new species shares some characteristics with other species of Ischnocnema and members of the Eleutherodactylus discoidalis group, and it appears closely related to I. sanctaecrucis.

We assessed the importance of tree buttresses as a microhabitat for leaf-litter amphibians and reptiles in a tropical wet forest in Costa Rica by making comparisons of species richness and abundance between pairs of 4 × 4 m leaf-litter quadrats. One quadrat in each pair contained a central buttressed tree, and the other did not. Both abundance and species richness of the herpetofauna were much greater in plots containing buttressed trees; higher species richness in buttress plots was attributed solely to greater abundance in these plots. Buttress and nonbuttress plots contained a similar species composition, and we found particularly strong use of this microhabitat by the scincid lizard Sphenomorphus cherriei. Our results indicate that the microhabitat provided by tree buttresses forms a site of generalized high abundance for the leaf-litter herpetofauna and may contribute to localized high abundance of at least one species.

We applied skeletochronology to a sample of Iberian spadefoot toads, Pelobates cultripes, from Serra da Arriça, an agro-forestal area in south-central Portugal marked by cool, rainy winters and hot, dry summers. These environmental conditions allow winter activities but constrain toads to a 12–16 week aestivation period. Lines of arrested growth (LAGs) in phalanges were easily readable albeit, unexpectedly, of varying distinctiveness. Double LAGs were scarce as predicted from the observation of a simple seasonal activity cycle. Limited endosteal resorption did not affect any LAG. Age of adult females ranged from 2–7 yr (N = 40) and that of adult males from 2–8 yr (N = 20). Mean adult snout–vent length (males, 52.8 mm; females, 54.2 mm) and growth rate were lower compared to other Iberian populations of spadefoot toads. However, von Bertalanffy growth curves predict much larger body sizes and greater longevity. We hypothesize that reduced growth rate is a consequence of lengthy, harsh summer conditions. Reduced longevity of spadefoot toads in the study area is probably related to local mortality factors, mainly road kill and land ploughing. Predictions of a postponement of age at sexual maturity at a smaller body size when conditions of reduced feeding and growth rate prevail were only weakly satisfied.

We describe a new species of Lampropeltis from the Pacific versant of the Sierra Madre Occidental in western México based on external morphology, scutellation, and molecular data. This species appears to be closely related to Lampropeltis pyromelana and Lampropeltis mexicana. Divergence may have resulted from geographic isolation on the west side of the Continental Divide in the Sierra Madre Occidental and subsequent adaptation to a unique ecological region.

Snakes are frequent predators of eggs and nestlings, but general patterns of snake predation at bird nests are not well known. We reviewed 84 video observations of snakes visiting nests of four songbird species in Texas and Missouri to identify patterns of predatory behavior. Eastern Ratsnakes (Elaphe obsoleta) were the most common species, and coachwhips, racers, kingsnakes, and a garter snake also were recorded. Snakes almost always removed all nest contents during a single visit but sometimes force-fledged nestlings that were old enough to escape. During many visits late in the nestling period, snakes pinned their prey in the nest while feeding, thereby preventing many of the young from escaping. Snakes spent an average of 13 min and 23 sec at each nest (1 min and 52 sec before striking), and the duration of nocturnal visits exceeded the duration of diurnal visits. Snakes sometimes returned to empty nests after they caused failure but only after nestlings were depredated. Visits by Texas Ratsnakes (Elaphe obsoleta lindheimeri) were mostly nocturnal, whereas visits by Black Ratsnakes (Elaphe obsoleta obsoleta), coachwhips, racers, and kingsnakes were diurnal. Snake predation increased as the nesting cycle progressed with the highest rate occurring in the last few days of the nestling period. Increased predation at the end of the nestling period suggests that avian activity (i.e., feeding visits, nest defense, and nestling movement) contributes to the foraging success of snakes at our sites.

I performed playback trials with and recorded vocalizations of male Pickerel Frogs, Rana palustris, in 1992–1993 and 1998–2000 at sites in Delaware and Pennsylvania. I also conducted a mark-recapture study of one population throughout its 1998 breeding season at the Ashland Nature Center, Delaware. Rana palustris had a prolonged breeding season with chorusing occurring over more than one month on nights that the air temperature was at least 8°C. Individual males during the breeding season participated in most choruses, were faithful to specific calling sites, and lost body mass. In the playback trials, I recorded male vocalizations during control conditions and after the playback of one conspecific advertisement call. Males had a complex vocal repertoire consisting of at least three call types: an advertisement call and two additional calls (“snicker” and “growl”) that were elicited by the playback stimulus or exchanged during natural male-male interactions. The three call types had distinct combinations of duration and pulse rate, and the snicker and growl had similar dominant frequencies that were significantly lower than those of the advertisement call. All males in the playback trials eventually returned to advertisement calling; however, these calls differed from the calls emitted during the control period in that they had shorter durations, longer rise times, and a shift of energy toward lower frequencies. Several males responded to the stimulus by emitting a series of underwater calls before returning to the water's surface and calling into the air. Overall, R. palustris has a complex communication system in terms of number of call types, the ability to alter call properties, and the ability to vocalize in both air and underwater.

Four new species of Cnemaspis are described from the Mentawai and adjacent archipelagos along the northwest to the southwest coast of Sumatra, Republic of Indonesia, and one each from Simeulue, Nias, Siberut, and Enggano. These populations were allocated by earlier workers to Cnemaspis kandiana (Kelaart, 1852), a Sri Lankan highland endemic. The high levels of endemicity of the fauna of these islands have been attributed to their geographical isolation, historical lack of aridity, and effects of glacial emergence of the Sunda Shelf caused by its maritime climate.

Male Dendrobates pumilio are territorial, and vocalize in the presence of intruders. Territory displays are energetically expensive, and residents should modify display behavior according to costs and benefits associated with social contexts of intrusions by conspecifics. Activity censuses found no significant difference in the proportions of male and female D. pumilio found at various times of day, but a higher proportion of animals that were active at 0730 were male. Resident males exhibited a significantly greater mean call group duration when faced with male intruders in the morning than in the afternoon but did not respond differently to male or female intruders. This may reflect greater potential benefits of repelling territorial intruders in the morning than in the afternoon and use of the same territorial displays to defend territory boundaries as well as to attract potential mates. No significant differences were found in responses of resident males to familiar and unfamiliar conspecifics, which suggests that both neighbors and strangers may compete with residents for territory and mates.

A variety of biotic and abiotic variables have been shown to affect length of larval period and size of juveniles at metamorphosis in amphibians. However, influence of water quality on phenotypic plasticity of growth and development of tadpoles generally has received less attention. We examined how abiotic factors in the larval environment change over time and how these changes affect the growth and development of larval amphibians. Western Chorus Frogs, Pseudacris triseriata, in tallgrass prairie breed in ephemeral aquatic habitats including intermittent streams and bison wallows. Our objectives were to determine whether abiotic factors in the larval environment of P. triseriata changed predictably as pools dried and to determine whether these changes affected growth and development of tadpoles when the environment was simulated in the laboratory. In our field studies, pH increased gradually in wallows, whereas ammonium increased in streams, as each habitat dried. In the laboratory, we examined the effects of increased levels of pH and ammonium on growth and development of tadpoles collected from both wallows and streams. Tadpoles collected from streams metamorphosed significantly faster in the high ammonium treatment than tadpoles from wallows. In contrast, tadpoles from wallows metamorphosed faster in the high pH treatment than tadpoles collected from streams. Growth rates of tadpoles from streams were not significantly affected by high pH, whereas those from wallows were not significantly affected by high ammonium treatments. We suggest that changes in abiotic factors over the course of the larval period may influence developmental rate and that natal habitat may determine how tadpoles respond to changes in abiotic factors.

Sumner Lake State Park, De Baca County, New Mexico, is the only known locality where three pattern classes of diploid, parthenogenetic Aspidoscelis tesselata (Sumner C, Sumner D, and Sumner E) coexist in syntopy. Reciprocal skin transplants confirmed that the pronounced phenotypic differences between Sumner C and Sumner E represent postformational genetic changes rather than separate hybridization origins. Sumner D is meristically indistinguishable from Sumner C and is considered to be a recent mutational derivative of the latter. In contrast, Sumner E is distinctly different from Sumner C in multivariate meristic characters and several important life-history characteristics. Discordant patterns of phenotypic variation characterize many geographically disjunct groups of A. tesselata classified as pattern class E, thus defying a cohesive diagnosis. Therefore, based on the evolutionary species concept (ESC), we consider Sumner C and Sumner E to be divergent clonal groups in the same species. We contrast this example with a parthenogenetic complex on the Yucatán Peninsula in which formal recognition of Aspidoscelis maslini and Aspidoscelis cozumela can be accommodated under the ESC.

The literature on Eastern Box Turtles (Terrapene carolina carolina: Emydidae) often characterizes them as terrestrial with only anecdotal references to their aquatic habits. The rapid decline in many populations of box turtles suggests an urgent need to assess all aspects of their habitat requirements. In this study, trailing devices and radio transmitters were used to determine seasonal movements and the extent to which turtles used aquatic habitats within their home ranges. Home range sizes averaged 1.88 ± 0.49 ha via minimum convex polygon analysis, and 2.26 ± 0.76 ha via 95% fixed kernel analysis. Kernel estimators were more effective at representing uneven home range use, often demonstrating the extensive use of water. A total of 131 turtles were found in two small temporary ponds from June through August. Individuals remained in the ponds for up to 23 consecutive days. As many as 32 turtles were found at one time in one of these ponds. Turtles often extended their home ranges by means of abrupt linear movements toward water in response to high temperature and low precipitation. Wet areas have a significant influence on Eastern Box Turtle life history. Box turtles should be considered in wetland area conservation decisions where appropriate.

It is generally accepted that bottom-dwelling turtles have a higher ectoparasite load than turtles that bask aerially because of effects of desiccation on ectoparasites, especially with regard to leeches. We compared number of leeches (primarily Placobdella parasitica) on field-caught Common Musk Turtles (Sternotherus odoratus) and Common Map Turtles (Graptemys geographica). The bottom-dwelling species S. odoratus had more than 20 times the number of leeches than the aerial-basking species G. geographica. We then exposed cleaned (leech-free) turtles to leeches in mesocosms (cattle tanks) to measure the rate of colonization. In this experiment, S. odoratus had more than four times the number of leeches as G. geographica after 24 h of exposure, even though G. geographica were unable to bask under these experimental conditions. We suggest that desiccation threat alone does not explain the species-specific differences in leech loads on aquatic turtles.

Toe-clipping is a simple and widely used method for permanently marking small lizards. Although some studies have shown negligible effects of toe-clipping on locomotor performance and survival in terrestrial lizards, less is known about effects of toe-clipping on arboreal lizards. We evaluated effects of toe-clipping on clinging performance of the small arboreal, pad-bearing lizard Anolis carolinensis. We also examined how clinging ability scaled with size within this species. We measured clinging ability in the same lizards with unclipped toes and with one (two toes clipped total) and two toes (four toes clipped total) clipped per each forelimb. We found that clinging ability decreased dramatically even after clipping only two toes (about a 40% decline) and even more dramatically after clipping four toes (about a 60% decline). We also found that clinging ability scales isometrically with body size within unclipped anoles. Because clinging ability was measured on a smooth substrate and was not influenced directly by claws, toe-clipping appears to directly affect toepad function. Toe-clipping may affect clinging ability because of the severing of a tendon that plays a key role in toepad function. Thus, we suggest that researchers should be cautious before applying toe-clipping as a marking technique to pad-bearing lizards.

We present the first report of aural abscesses in Ornate Box Turtles, Terrapene ornata, and of an epidermal inclusion cyst in Painted Turtles, Chrysemys picta. These observations were made in a mark-recapture study in eastern Iowa conducted over 25 yr. Detailed records of facial lesions in these species have been maintained for the last 12 yr. The prevalence of aural abscesses is lower than that reported for Eastern Box Turtles, Terrapene carolina. Aural abscesses tend to develop in Ornate Box Turtles at least 13 years old and are more common in females than males. The cysts sometimes spontaneously resolve but, in one instance, returned after being expelled in the field. In Ornate Box Turtles, they arise in the middle ear and displace the tympanum and its cartilaginous inner coat outward. Infection sometimes results in reactive bone formation with distortion of the cranium. A similar appearing lesion in a Painted Turtle arose in the skin covering the tympanum, and a second arose anterior to the ear. These were epidermal inclusion cysts and not abscessed.

Osteological characters are used to infer the phylogenetic relationships of the Venezuelan toad, Bufo sternosignatus. The species does not have a ventrolateral process on the quadratojugal, a synapomorphy for the especies of the B. typhonius clade and is associated to B. humboldti a species of the B. granulosus group.

Boa constrictor was first documented on the island of Aruba in April of 1999. By the end of December, 2003, 273 B. constrictor had been captured. These snakes ranged in size from neonates (0.30 m total length) to large adults (2.8 m total length) and included at least two gravid females. Boa constrictor is currently distributed islandwide with the highest frequency of occurrence in the southern and southeastern portions of the island. The increasing frequency of occurrence, extensive distribution, and size diversity of B. constrictor indicate that a large, reproductively successful population is established on Aruba. The diet of the B. constrictor on Aruba was determined from the examination of stomach content and scat samples (N = 47). Birds comprised 40.4%, lizards 34.6% and mammals 25.0% of 52 separate prey items identified. A correlation was found between snake total length and prey mass (r₍₂₈₎ = 0.49, P < 0.01) suggesting an ontogenetic shift in the diet at a total length of approximately 1.0 m. In view of the diverse diet and increasing population of B. constrictor, there is concern about the potential impact of this invasive predator on the Aruban fauna. A government instituted euthanization program for all captured B. constrictor has proven ineffective at controlling the population.

Radio-telemetry was used to study spatial ecology of a Cottonmouth (Agkistrodon piscivorus) population in eastern Texas. I examined effects of sex, reproductive state, and body size on spatial use within a riparian habitat. Snakes inhabited a relatively linear environment, restricting movements to the vicinity of the stream. Males occupied larger home ranges than both gravid and nongravid females. Gravid females exhibited marginally larger home ranges than nongravid females, but any effects attributable to reproductive state were relatively small when compared to sex differences in spatial use. Body size was positively correlated with home-range size but did not account for observed home-range differences among population subunits.

We simulated nests constructed in an area heavily used by ovipositing Diamond-backed Terrapins (Malaclemys terrapin) and foraging raccoons (Procyon lotor), to investigate the cues used by raccoons to locate terrapin nests. Marking nests with flags did not increase predation rates, and human scent decreased predation rates. Raccoons seemed to locate nests based on soil disturbance, ocean-water scent, or a combination of these cues.

Sexual dimorphism in body size, body condition (body mass relative to body size), and relative head size was investigated on 1250 field-caught Python regius (Togo, western Africa). Sexual dimorphism was often undetectable in neonates. By contrast, sexual dimorphism was apparent for many traits in adults. Adult females were larger and had a higher body condition than males; they also had longer jaws relative to their body size. This suggests that females and males follow different growth trajectories from birth to adulthood. In support of this, neonate females had a higher postnatal growth rate than males. Fecundity was strongly correlated with body size in females; a larger body size may be favored by fecundity selection in this sex. Our data show that females mature at a large body size: 95 cm in snout–vent length (SVL). The estimated external parasite load (number of ticks) was higher in adult males than females, perhaps because males encounter more ticks during movements.

Herbivorous reptiles use microbial gut symbionts to digest plant material. These symbionts ferment cell wall components, producing short-chain fatty acids (SCFA), which the host uses as an energy source. In reptiles, fermentation usually occurs in the large intestine; however, the freshwater Florida Red-Bellied Cooter, Pseudemys nelsoni, has both small and large intestine fermentation. Although small intestine fermentation has not been found in other chelonians, no other freshwater turtles have been examined. We measured SCFA concentrations in the digestive tracts of juvenile and adult Pond Sliders, Trachemys scripta. Like many other turtles, T. scripta experiences an ontogenetic diet shift from carnivory to herbivory, and it is unknown whether juveniles can digest plant material. We determined whether (1) this species harbors small intestine fermentation, (2) juveniles possess SCFA concentrations comparable to other herbivorous reptiles, and (3) a change in relative fermentation chamber capacity accompanies the diet shift. We fed turtles a plant diet for five weeks and then measured SCFA concentrations in their gastrointestinal tracts and the mass of gastrointestinal tract contents. Both juveniles and adults had SCFA concentrations comparable to other herbivorous reptiles; however, they did not have significant small intestine fermentation. Additionally, there was no difference between the relative masses of juvenile and adult fermentation chamber contents. Therefore, the ontogenetic diet shift in T. scripta is not accompanied by a change in relative gut capacity.

A single display may be used in more than one context and, as such, may convey different information to different receivers. Tail displays in lizards are often performed in several contexts, and appear to have many functions that vary both within and between species. We examined the function of tail displays in a small scincid lizard, Carlia jarnoldae, capable of tail autotomy. We quantified the use of these displays by resident males by observing them in one of four controlled contexts: alone, with a conspecific male, with a conspecific female, or with a predator. We also compared the number of resident versus intruder males that performed tail displays. We found that resident males performed tail displays in all experimental contexts, but most frequently in the presence of a conspecific male and a predator. In contrast, intruder males almost never performed tail displays. The results suggest that tail displays may play important roles in male social interactions and in signaling to predators.

Radiographic and histologic examination of long bone epiphyses in 25 species of Varanoidea (including one Heloderma species) reveals a qualitative difference in epiphyseal development between small and large species. In small monitor lizards, most of them belonging to the subgenus Odatria, metaphyseal plates tend to disappear completely, with fusion of primary and secondary epiphyseal ossification centers in adults that reach an individual body length close to the maximum known for their species. Epiphyseal fusion results in a complete and irreversible arrest of growth. This observation falsifies the previously accepted conclusion that the monitor lizards as a whole have a continuous growth. Conversely, in larger species, morphologically complete growth plates remain present in most (but not all) specimens, including very large adults. Although this feature is not firm evidence of a continuous growth, it nevertheless suggests that large species maintain active growth during ontogeny over a longer period than small species.

The Texas Horned Lizard (Phrynosoma cornutum) is a species of special conservation concern in Texas and the southwestern United States.This study was designed to compare capture rates of adult female and male Texas Horned Lizards by time and month. Horned lizards were captured by road cruising at Chaparral Wildlife Management Area in southern Texas. We found a female bias in morning capture rates compared with evening capture rates. These sex-specific differences in timing of activity may indicate an important difference in physiological constraints on the sexes. Sex-biased movement patterns must be accounted for in population sampling and plans to conserve this imperiled species.