Protein pheromones in salamanders of the genus Plethodon have experienced rapid and pervasive directional selection. Variation in mate recognition components, such as the sex-specific pheromones used by plethodontid salamanders, may influence sexual incompatibility and therefore provide a biochemical mechanism for the maintenance of discrete, isolated populations. Recent studies suggest that multiple, genetically distinct lineages of Eastern Red-Backed Salamanders (Plethodon cinereus) are present throughout their broad range. Representative populations from two of these lineages (the Ohio [OH] and Pennsylvania [PA] clades) span the southern shore of Lake Erie in northern Ohio. This distribution pattern creates a unique opportunity to study how phenotypic differences may reinforce population boundaries and possibly lead to speciation. The objectives of this study were to 1) characterize the pheromone profiles of male P. cinereus and 2) determine pheromone variation among populations and between the OH and PA clades. The composition of proteins associated with two known courtship pheromones, Plethodontid Modulating Factor (PMF) and Plethodontid Receptivity Factor (PRF), were compared among eight populations in northern Ohio. Analyses of Similarity (ANOSIM) suggest that both PMF and PRF profiles differ among populations but not between clades. These data suggest that the sex-specific pheromones of P. cinereus in the two clades are not yet different enough to allow reproductive isolation between the two genetic lineages. Although the relative roles of selection and genetic drift are unknown in our populations, specific pheromone isoforms and their effects on mate compatibility should be the focus of future studies aiming to determine mechanisms involved in maintaining population differences.

Occupancy modeling may be the most effective tool for studying the occurrence of secretive fossorial squamates. Our objective was to use occupancy models to test whether Florida Crowned Snakes (Tantilla relicta) are a suitable model species for other, more-secretive fossorial squamates. Tantilla relicta are easier to study than other fossorial squamates and likely respond to habitat management (e.g., fire frequency) similarly to these harder-to-study species of concern. We sampled T. relicta using 24 groups of drift fences in longleaf pine–wiregrass sandhills, Ocala National Forest, Florida, USA to assess how habitat characteristics and weather influenced their occupancy, detection, colonization, and extinction rates. We predicted that temperature, rainfall, substrate composition, and prescribed burn history would influence T. relicta occupancy, detection, and movement in variable directions. The best-supported multiseason occupancy model included 1) initial occupancy influenced by time since last burn, 2) extinction and colonization as random processes, and 3) detection influenced by percent leaf litter and rainfall. Tantilla relicta were most likely to occupy recently burned sites and were most easily detected during dry periods and at sites with low leaf litter cover. Our results are consistent with research suggesting that short-return prescribed fires benefit many reptile species in central Florida's xeric longleaf pine–wiregrass forests. Further, our results provide modest evidence that T. relicta are suitable model organisms for studying fossorial squamate assemblages.

Habitat selection is dependent on several abiotic and biotic factors which have influence at multiple spatial scales. Dependence on specific habitat characteristics for thermoregulation could make habitat selection by herpetofauna especially subtle. Enhancing knowledge of habitat selection by herpetofauna is critical for completely understanding natural histories and improving future habitat management strategies. We conducted a year-long telemetric habitat selection study on two Northern Cottonmouth (Agkistrodon piscivorus) populations in northeast Texas. We used a use–availability approach and investigated intersexual differences at three spatiotemporal scales: home range selection within the study site (home range selection); habitat selection within the home range (macrohabitat selection); and fine-scale local habitat selection (microhabitat selection). The home range selection of both males and females exhibited selection for edges and avoidance of pasture. Males only exhibited macrohabitat selection in the summer, when they selected edge and wetland. Females did not exhibit any macrohabitat selection. Males and females selected microhabitats with thick vegetation in the spring and summer. However, in the fall, male microhabitat selection was influenced by lower temperatures and female microhabitat use appeared to be driven by parturition. Although our study suffered from small female sample size and a short time frame, we provide insight into the complex habitat selection of Cottonmouths in northeast Texas.

Countergradient variation (CnGV) in physiological traits exists among populations of broad-ranging ectotherms. Relatively few studies, however, have addressed the underlying biochemical mechanisms that support enhanced growth and development. We aimed to determine whether CnGV in embryonic development occurs in the Prairie Lizard (Sceloporus consobrinus) and to assess possible mechanisms that contribute to differential embryonic development. We investigated differences in embryonic development between two populations of S. consobrinus from different latitudes by tracking metabolic metrics throughout the incubation period. We found metabolic differences between the two populations that were similar to those observed S. undulatus, a previously studied sceloporine lizard that displays CnGV in development, suggesting that embryos from the high latitude population were developing at a faster rate than those from a lower latitude. However, contrary to our original predictions, aerobic metabolic enzyme activity did not differ between populations. Finally, we found some evidence of a trade-off between embryonic developmental rate and mortality as well as between embryonic and hatchling anaerobic enzyme performance. Our results corroborate previously implicated proximate mechanisms of CnGV in developmental rate in a new lineage of sceloporine lizard. In addition, our results show a novel detriment to embryonic survival in the high latitude population, highlighting that we do not yet understand the complexities of the developmental trade-offs experienced across latitudes.

Rio Grande Cooters (Pseudemys gorzugi) are one of the least studied species of freshwater turtles in North America. Rio Grande Cooters are listed as a state threatened species in New Mexico and near threatened by the International Union for Conservation of Nature. Given their conservation status, it is important to understand the natural history of this species. We conducted the first in-depth investigation of the dietary habits of P. gorzugi at two sites within the Black River in Eddy County, New Mexico, USA, by using fecal sample analyses. We captured and attempted to collect fecal samples from 277 turtles (205 nonrecapture, 72 recapture) and successfully collected 78 samples. Fecal content analysis revealed vegetation including netleaf hackberry (Celtis reticulata), cottonwood (Populus sp.), willow (Salix sp.), monocot grasses, and filamentous algae, along with animals including nine orders of insects, a crustacean, a feather, a fish vertebra, and monofilament fishing line. We found that turtle diets were omnivorous to varying degrees between sexes. Dicot vegetation, filamentous algae, and arthropods were found to be the most important diet components in male (index of relative importance [IRI] = 0.47), female (IRI = 0.53), and juvenile (IRI = 0.63) P. gorzugi, respectively. Juveniles were found to have a more specialized diet or lesser dietary breadth compared with diets of adult males and females. Future studies should investigate the nutritional value and digestibility of dietary resources, interspecific competition, and comparison of diet of P. gorzugi from different river systems.

Kentropyx calcarata is a widely foraging teiid lizard species that inhabits forest environments east of the Andes in South America. We studied the ecology of a K. calcarata population in a remnant of Atlantic Forest in Brazil and evaluated lizards' body temperatures, stomach content, activity time, body measurements, and reproduction stage. We tested whether: 1) body temperature was influenced by substrate or air temperatures, 2) diet composition varied according to age and sex, and 3) there was sexual dimorphism in body size and bauplan (morphology). Lizards were more active during the hottest hours of the day, commonly in the litter or fallen logs. Body temperatures were influenced more by substrate temperatures than by air temperatures. Diet was composed mainly of arthropods, with Orthoptera and Araneae as the most important categories (numerically and volumetrically). Diet composition was similar between sexes, but varied ontogenetically as an effect of body size, with juveniles eating smaller prey than adults. Females were larger than males and there was difference in bauplan between sexes. We found reproductive males and females throughout the year. Kentropyx calcarata is ecologically similar to other species within the genus and the family, suggesting great importance of the evolutionary history for the ecology of this species.

The tadpole of Altiphrynoides osgoodi is described on the basis of material collected in 1975 near Goba, Ethiopia. The tadpole resembles typical bufonid tadpoles in its general shape and size, but differs in several characters from other known African bufonid tadpoles. It is characterized by very large nostrils and an indistinct (in preservative), but long, slitlike spiracular aperture. The buccopharyngeal morphology is overall similar to that reported for other African bufonids and shows the most similarities with Schismaderma carens. The gut of a Gosner stage 34 tadpole contained items that were apparently ingested as well as large amounts of yolk within the intestinal tissue, suggesting that A. osgoodi tadpoles may be facultatively nonfeeding.

The Plateau Pit Viper, Gloydius strauchi, from southwest and central China has long been considered a single, widespread species despite suspicion that it represents a potential complex of distinct evolutionary lineages. Although series of works were published on the G. strauchi species complex over the last 10 yr, species boundaries and diagnostic features of different members of the complex have remained poorly understood. Combining both morphological and genetic data, we re-evaluate taxonomic statuses of populations of G. strauchi in southwest China and describe the eastern Tibetan populations as a new species. The new species is most closely related to G. monticola phylogenetically, and it differs from all congeners by having a matte dorsal body scale texture, oval and robust head shape, distinct body ornamentation and coloration, and unique hemipene morphology. In addition, we provide the first updated diagnostic key to all recognized members of the G. strauchi species complex, and discuss ongoing taxonomic problems associated with cryptic diversity within the genus in China.

We analyzed the diet of a litter-dwelling microhylid frog, Chaperina fusca, from the lowland rainforest of Borneo. We flushed the stomachs of 194 frogs: 94.8% had contents and 5.2% were empty. Although the diet composition of C. fusca was diverse, with 27 prey categories, we found that ants, mites, beetles, and springtails, in that order, dominated its diet both numerically and volumetrically. Among these four categories, however, ants were by far the most frequently consumed in both number (63.5%) and volume (82.6%) and in higher proportion than in the leaf litter. A novel aspect of our study, conducted in only a limited number of studies of anuran diets, was to determine the ant genera consumed. We identified 41 ant genera consumed by C. fusca whereby the genera Lophomyrmex, Pheidole, and Tetramorium were the most prominent. We also recorded a significant relationship of prey volume and number with both body size and mouth width of frogs. Our data provide circumstantial evidence that C. fusca is an ant-specialist feeder and active forager. These results are in line with the dietary characteristics of many terrestrial microhylid frogs in subtropical and tropical Asia, the Neotropics, and the Afrotropics.

Many amphibians in temperate zones need to time their reproduction in spring carefully, as they need to find a partner, mate, and oviposit in good time to ensure that their offspring metamorphose before the terrestrial phase starts. Therefore, embracing as many mating opportunities as possible, especially early in the mating period, would be advantageous. Here we examine the temporal pattern of mating activity in Alpine Newts, Ichthyosaura alpestris. Males exhibit a highly complex courtship ritual, during which both olfactory and visual signals play a prominent role. The aim of this ritual is a close coordination between the movements of the male and the courted female, a prerequisite for successful spermatophore transfer. We observed mating activity in a large, group aquarium with a natural photoperiod. We recorded the number of mating pairs at every full hour over the course of 4 d, during light and dark conditions. We observed most courtship behavior during light conditions when males were able to guide females properly with visual cues to the spermatophore. Although greatly reduced, we also found some mating activity in dark conditions on the first experimental day; however, mating activity decreased drastically during the following dark phases. Our findings demonstrate that Alpine Newt males that have access to females over several days use mating opportunities predominantly during light conditions, when visual cues can be utilized optimally. Although olfactory cues might be important during mating, our data suggest that visual cues may confer an adaptive advantage during mate choice.

Limb reduction among squamate clades is common; limbless (forelimbs, hindlimbs, or both) forms have had at least 25 independent origins among snakes and lizards. The general evolutionary pattern is the gradual loss of limb elements proceeding from the toes to the shoulder or hip. In contrast, forelimbs are not known to have ever existed in snakes. Forelimbs are not known for either stem or crown snakes; snake fossils lack forelimbs and the embryos of modern snakes lack the signaling pathways that initiate forelimb development. Both fossil and developmental data thus imply an abrupt loss of forelimbs. In contrast, the well-developed hindlimbs of the oldest fossil snakes and vestigial hindlimbs of some basal clades of modern snakes imply the historical presence of hindlimbs, and their gradual reduction during snake evolution. In contrast, observations on limb-reduced lizards are in accord with gradual reduction of both fore- and hindlimbs; embryos of even limbless species initiate limb development. The question then arises, have any clades of limbless lizards become limbless abruptly, as have snakes? To address this question, I examined limb development in the family Pygopodidae. Like basal snakes, pygopodids are characterized by the absence of forelimbs and by vestigial hindlimbs. My observations on the development of forelimb buds in Delma molleri support gradual limb reduction, as do observations on other limbless lizards. Nonetheless, many clades of limbless lizards are yet to be studied and hence provide a wealth of opportunities to address modes of limb reduction and loss in squamate reptiles.