Reports of severely malformed amphibians in the 1990s prompted researchers to examine the causes and extent of the issue. However, disparities in survey methods and a shortage of baseline data have hindered standardization among investigations. Here, we review field-based surveys and experimental approaches used over the last decade to address this complex ecological issue. We offer specific recommendations regarding amphibian-sampling techniques, including methods to capture and examine amphibians, with the aim of enhancing the accessibility of this topic to scientists, students, and educators of diverse backgrounds. Based on established approaches from epidemiology, we provide recommendations regarding methods to identify proximate causes(s) of abnormalities with a focus on using “multiple lines of evidence,” including large-scale field surveys, comparing malformation “signatures” between field and laboratory studies, and using of manipulative experiments at multiple spatial scales. As an example, we describe methods to examine the causal influence of infection by the trematode parasite, Ribeiroia ondatrae, including quantifying presence and abundance within amphibian and snail host populations with adequate power of detection. We conclude by identifying outstanding questions with the goal of stimulating additional research to evaluate the causes and consequences of amphibian malformations.

Coverboards have been used for decades in research on amphibians and reptiles, but their characteristics have varied widely. This diversity in design may both complicate comparisons among studies and preclude assessment of how coverboards could be deliberately tailored to specific study objectives. Although numerous studies have evaluated the effectiveness of various aspects of coverboards, a general synthesis of these results as they relate to salamanders is lacking. Here, I summarize and evaluate information relating to coverboard design and potential concerns for using coverboards in studies of salamanders.

We review the natural occurrence of tail duplications and tail bifurcations in amphibians as well as experimental studies that induced tail duplications. For natural populations, we found 10 publications that mention tail duplications or bifurcations in a total of 24 individual larval amphibians belonging to 15 species, mainly from Europe and South America. Nineteen publications describe the incidence for 34 individual postlarval urodeles from 12 species from North America, Europe, and Asia. Here we add three new observations: a subadult female Triturus dobrogicus with a duplicated tail and an adult female Triturus carnifex with a bifurcated tail from Hungary, and a tadpole of Hyla arborea with a bifurcated tail tip from Greece. The causes of tail duplications in wild amphibians remain unknown. Similar tail anomalies have been obtained in the laboratory when parts of the chorda dorsalis were destroyed, when tar is injected into the tail, or when the lumbar region is irradiated.

We studied spatial clustering and activity patterns in the common Barking Gecko (Ptenopus garrulus garrulus) over the course of a breeding season in southern Africa. Only some populations exhibited significant clustering (two of six plots), suggesting that social and spatial organization varies according to factors such as population density and habitat. Clustering at our largest site was not influenced by soil temperature or prey availability, although burrow placement was significantly associated with vegetation coverage. We also examined the timing of the reproductive cycle by testing whether Barking Geckos exhibit protandry (male-first emergence). More males than females were active early in the breeding season and male territories were established before female emergence. Peak activity for 235 Barking Geckos at our primary study site was in late October, although males were significantly more active early in the season, consistent with the protandry model. The Barking Gecko mating system is most consistent with an iteroparous, harem polygynandry with an activity cycle that exhibits protandry. Our study highlights the importance of replicated spatial sampling for studies examining clustering and density effects on reproduction and mating systems.

Color is important for signaling, camouflage, and thermoregulation in many species. The costs and benefits of coloration can vary under different scenarios, increasing fitness under some conditions but decreasing it under others. Some animals are able to resolve these conflicts by changing color. Color change can increase fitness by maintaining crypsis across variable environments, by minimizing costs associated with signaling, and by aiding thermoregulation when environmental conditions change. We examined the effect of temperature on short-term color change in males of the sexually dichromatic Eastern Fence Lizard, Sceloporus undulatus. Color is associated with social dominance in this species and may be important in facilitating camouflage and thermoregulation. This study revealed that dorsal color and badge color are affected by temperature. This suggests that short-term color change in this species may aid thermoregulation and provide an honest signal of thermally dependent performance.

We describe adult morphology, advertisement call, and natural history aspects of a new frog species from riparian habitats alongside intermittent headwater streams in southwestern Cerrado, the second largest biome in Brazil. Presently known from three localities in Mato Grosso State, the new species belongs to the Proceratophrys cristiceps group. It is characterized mainly by small size (adult snout–vent length approximately 46 mm), snout rounded in dorsal view and obtuse in lateral view, absence of flared lips, dorsal skin granular, and absence of both postocular swellings and prominent palpebral appendages. The advertisement call of the new species consists of a single note with 19–25 pulses. Calls are repeated at mean intervals of 0.7 sec. Mean dominant frequency is 1,250.2 Hz, with ascendant modulation.

Descrevemos a morfologia, canto de anúncio e aspectos da história natural de uma nova espécie de anuro habitante de matas ripárias ao longo de córregos intermitentes da porção sudoeste do Cerrado, o segundo maior bioma do Brasil. Conhecido atualmente de três localidades no estado do Mato Grosso, a nova espécie é pertencente ao grupo de Proceratophrys cristiceps. A nova espécie é caracterizada principalmente por seu pequeno tamanho (comprimento rostro-anal em adultos cerca de 46 mm), focinho arredondado em vista dorsal e obtuso em vista lateral, lábios sem borda projetada, pele granular e ausência de entumescimento pós-ocular e de apêndices palpebrais. O canto de anúncio da nova espécie consiste em uma nota simples com 19 a 25 pulsos. O canto é repetido em intervalos médios de 0,7 sec. A freqüência dominante apresenta média de 1,250,2 Hz com frequência modulada ascendente.

We describe Incilius aurarius sp. nov., a new species of toad known from several localities on the humid Caribbean slopes of the Sierra de los Cuchumatanes in Huehuetenango, Guatemala, and adjacent highlands of Chiapas, Mexico. This species previously has been confused with populations of Incilius valliceps and Incilius macrocristatus. The new species is morphologically similar to the Mexican species I. macrocristatus but differs by having less prominent crests, a distinctive golden coloration in the males, and the absence of vocal slits.

We describe a new species of Rhacophorus from lowland forests in southern Vietnam. The new species is most similar to Rhacophorus kio, but differs from this and all other Rhacophorus from Southeast Asia by a combination of its large body size (males 72.3–85.5 mm; females 89.4–90.7 mm snout–vent length); green dorsum; white venter; black patch at axilla; bluish-green posterior surface of thighs with pale yellow marbling; low, single-lobed supracoloacal dermal ridge, and white sclera. In contrast to the widely distributed R. kio, the new species is known only from two fragments of disturbed, low-elevation forest approximately 30 km apart in a highly modified agricultural landscape. The continued survival of the new species is threatened by ongoing habitat loss and degradation.

A new species of Cyrtodactylus is described from foothill forest on the northern edge of the Finisterre Range, northeastern Papua New Guinea. The new species can be distinguished readily from all other Melanesian Cyrtodactylus by the combination of small size (adult SVL <72 mm), males with small number of pores in independent precloacal (11 pores) and femoral series (seven pores on each leg), possession of a patch of enlarged precloacal scales, absence of transversely enlarged subcaudal scales, and light-brown dorsal coloration with indistinct to distinct thin darker-brown transverse bands. The new species is the second-smallest Cyrtodactylus known from New Guinea. We propose that it may be a relic of a formerly insular fauna originating on the Finisterre Terrane but now accreted onto mainland New Guinea.

A new, medium-sized limbless Acontias lizard is described from Zambia. The new species is characterized by a concealed eye, four chin shields bordering the mental, 14 scale rows around midbody, and a unique coloration of a dark dorsum and a pale ventrum. The species is similar to its congener Acontias jappi, but distinct in aspects of pholidosis, and was assigned to the genus Acontias using external morphological as well as osteological characters. The specimen was collected on Kalahari sands at Kataba Forest Reserve in the western part of the country.

The Indonesian parachuting frog Rhacophorus catamitus is endemic to the mountains of southern Sumatra. Herein, we describe the larval morphology of this species based on several developmental stages. Tadpoles were collected from localities that ranged in elevation from 1,068–1,680 m in montane primary and secondary growth rainforest habitats. We matched larvae to an adult paratype and a referred specimen using mitochondrial DNA. The tadpole of R. catamitus has a conspicuous black tail tip and a larval morphology similar to most congeners. Characteristics of this body plan include a ventral oral disc, jaw sheaths, several labial tooth rows, dorsolaterally positioned eyes, a single sinistral spiracle, and a median anal tube. All specimens (N = 28) have a large suctorial oral disc with 9–11 tooth rows (6–8 anterior, 3 posterior) that we hypothesize is an adaptation for life in fast-flowing streams. At least two size cohorts of R. catamitus larvae were collected in June 1996, suggesting that this species may breed either continuously or opportunistically throughout the year.

Urban areas can contain habitat that supports amphibian populations, such as artificial ponds. We sampled a less than 3-m² pond in the city of Oviedo (North Iberia) and found abundant populations of two anurans (Alytes obstetricans, Discoglossus galganoi) and one urodele (Lissotriton helveticus). The three species present at the urban site exhibited high diversity in their mitochondrial DNA, comparable to levels found for populations in nearby rural areas that contained more and larger water bodies. Our results suggest that urban ponds should be incorporated into amphibian conservation plans.

We examined the diet of the Milksnake (Lampropeltis triangulum) in the western United States and evaluated predictions about ontogenetic shifts, sexual divergence, and geographic variation in diet. Identifiable prey items were found in 139 specimens, and 41 additional prey items were recorded from the literature, for 180 prey items in total from 175 individual snakes. Lampropeltis triangulum is a generalist predator and feeds primarily on lizards and mammals. Skinks made up a large portion of the total diet. Other lizard taxa were also important prey, whereas reptile eggs, snakes, and birds were consumed infrequently. Ontogenetic shifts in diet were documented. The upper size limit of prey increased with increasing snake size, and adult snakes continued to feed on small prey. Prey type also was related to snake size. Juveniles fed more frequently on lizards, but adults fed mainly on mammals. Although males were longer than females, there was no sexual size dimorphism in mass, and there were no differences in diet between sexes. Diet varied geographically, and the proportion of endothermic prey was greater at higher latitudes after accounting for snake size.

We investigated responses of adult and juvenile Desert Nightsnakes (Hypsiglena chlorophaea) to odor extracts of potential invertebrate and vertebrate prey. Snakes were collected during 2009 from three localities in Washington state. We obtained odor from three potential invertebrate prey—spider (Tegenaria spp.), scorpion (Paruroctonus boreus), and field cricket (Gryllus spp.)—and compared responses with a vertebrate prey item, a Western Terrestrial Gartersnake (Thamnophis elegans). All potential prey items were collected at the same site as H. chlorophaea. We presented odors on 15-cm cotton swabs held 2.5 cm in front of the snake's snout. For each trial we recorded the number of tongue flicks in 60 sec, the latency to first tongue flick, and whether the stimulus elicited an attack. We observed no significant difference in latency of responses between spider, scorpion, cricket, or snake odors. However, both adult and juvenile H. chlorophaea responded with higher tongue-flick rates to snake odor. Juveniles showed an increase in tongue-flick rate toward crickets. Attacks were made against snake odor with no difference between adult and juvenile responses. Our results indicate that adults and juveniles of H. chlorophaea do not feed on invertebrates, and in some cases invertebrates may pose a threat to small snakes such as H. chlorophaea. However, the diet of H. chlorophaea may vary geographically, and populations of H. chlorophaea with a more southerly distribution may feed on invertebrates. Whether such differences in diet exist between populations will remain unresolved until additional studies of the diet of southern populations of H. chlorophaea are compared with those of northern populations.

Habitat structure is known to influence community interactions, but its role in amphibian communities is unclear. Our objective was to examine the effect of vegetative habitat structure, in the presence or absence of a crayfish predator (Orconectes rusticus) and the herbicide atrazine, on Green Frog (Rana clamitans) tadpoles reared in 10-L microcosms in the laboratory. Crayfish predators reduced Green Frog survival and affected activity levels and microhabitat use differently depending on the presence or absence of vegetation. In treatments with vegetation, activity levels were greater when the crayfish predator was absent, but in treatments without vegetation activity levels did not differ between predation treatments. Moreover, when a crayfish predator was present, tadpoles in treatments without vegetation spent more time at the water surface than tadpoles in treatments with vegetation. This preference for the water surface may have been a compensatory behavioral change to avoid predation because it was less likely that crayfish would be able to reach the upper portion of the tank in the absence of vegetation. Atrazine exposure did not significantly influence susceptibility of Green Frog tadpoles to crayfish predators or alter the impact of vegetation. We found that vegetative habitat structure can mediate predator–prey interactions; however, contrary to previous studies we found that the presence of vegetation may benefit the crayfish predator and result in both lethal and sublethal effects on tadpole prey.

Female mate choice preferences may be the result of innate factors, experience, or an interaction between the two mechanisms. Understanding the relative contribution and possible interaction between these mechanisms is important for identifying sources of variation in behaviors under sexual selection. In this study, we evaluate the contribution of early experience on the development of mate choice preferences in the Neotropical Túngara Frog, Physalaemus pustulosus. We reared frogs from tadpole stage through sexual maturity in four acoustic treatments: the first group heard a conspecific chorus of Túngara Frogs, the second group heard a heterospecific chorus of the closely related sympatric congener P. enesefae, the third group heard no frog sounds, and the fourth group heard only broadband white noise. At sexual maturity, we tested each female's preferences for conspecific complex vs simple calls and discrimination against calls of the sympatric congener. Female choices in all of these tests were consistent with those in previous studies of wild-caught and laboratory-reared specimens of this species. The acoustic rearing environments in this study did not alter the preferences of females for complex conspecific calls or the discrimination of females against the sympatric congener. This study supports the hypothesis that early experience does not alter the mate choice preferences of female P. pustulosus.

Knowledge of movements, habitat use, and resource requirements is critical to designing management strategies for species with a conservation status. For snakes, basic research needed to derive this information is often lacking or insufficient. We used radio telemetry to investigate the spatial ecology and habitat use of 21 adult Western Foxsnakes (Pantherophis vulpinus) during a single activity season at Squaw Creek National Wildlife Refuge in northwest Missouri, near the species' southern range limit. At the landscape level, monitored snakes located their home ranges in lowland areas in association with wet prairies and managed wetlands but avoided agricultural plots and were not observed to occupy upland areas. Snakes were not selective of macrohabitat within their home ranges but selected microhabitats with denser herbaceous vegetation than typically available at random sites, suggesting that snakes were responding mainly to microhabitat features at the home-range level. Unlike many other temperate snake species, P. vulpinus did not exhibit any sexual differences in selection of microhabitats because all snakes appeared to prefer dense vegetative structure. Home-range sizes were relatively large in comparison to many other terrestrial temperate colubrids and seemed to be explained by resource distribution patterns, such as the proximity of hibernacula and oviposition sites to foraging habitat. Movement patterns varied seasonally among sexes with males demonstrating peak movement distances in May and females in July, respectively. Management decisions to minimize habitat manipulations during the snake activity season and protect embankments used for hibernacula and oviposition will likely benefit Foxsnake conservation.

Field observations and mark–recapture sampling carried out in the Reserva Ducke in Central Amazonia provided information on the occurrence of reproductive events of the Brilliant-Thighed Frog, Allobates femoralis, in the context of seasonal rainfall. In addition, we report on the daily pattern of calling activity and the use of space by marked individuals. Rainfall was a strong determinant of the calling and breeding activities at a seasonal scale. The phenology of A. femoralis was affected by interannual differences in both the length and severity of the dry season. This species showed a consistent diel pattern throughout the year, with calling activity peaking between 1500 and 1600 h. At the seasonal scale, calling activity was higher during the wet months and was correlated positively with monthly rainfall. Although recruitment is concentrated in the late wet season, our observations of juveniles in the smallest size classes throughout the year indicated that reproduction occurs sporadically even during the dry season, probably stimulated by isolated episodes of rainfall. Territories varied greatly in size, ranging from 4.8 to 175.7 m². Females did not establish or defend territories. Individuals of both sexes showed regional interseasonal attachment, and males maintained territories for up to 255 days.

We investigated the relation between heterophil/lymphocyte ratios, hepatozoon parasitemia, and two presumed fitness correlates (residual body condition and growth rate) in two regional populations of the Eastern Foxsnake, Pantherophis gloydi. Parasite intensity was not related to either fitness correlate. We found a significant relationship between log (heterophil to lymphocyte [H/L] ratio) and residual growth rate for individuals from Georgian Bay, but not those from southwestern Ontario. There was no significant relationship between log (H/L ratio) and residual body condition in either regional population. We also detected dramatic differences in parasite prevalence and H/L ratios between the two populations: Almost half of the sampled individuals from Georgian Bay were infected with hepatozoons compared to only 2 of 46 infected individuals from southwestern Ontario; H/L ratios were significantly higher in Georgian Bay individuals implying that individuals in this northern population experience higher levels of stress than those in southern Ontario where the environment differs markedly.

We analyzed the diet composition of adult Common Toads (Bufo bufo) in Europe to define their general diet preferences with the use of data collected in Serbia and published data from Great Britain, Spain, France, Poland, Hungary, Belarus, and Bulgaria. We also addressed the potential correlation between adult body size and prey size, and sex-based food niche partitioning in adults as suggested by the pronounced sexual size dimorphism in this species. Analysis revealed that European Common Toads feed most frequently on insects, e.g., Coleoptera and Hymenoptera (Formicidae), but food diversity may vary among regions. A number of other invertebrate taxa were included in the diet, though usually in frequencies less than 0.1. The results suggest that the Common Toad is neither a feeding generalist, nor a myrmecophagous specialist, as some bufonids are proclaimed to be. In-depth analysis of samples from Serbia revealed no correlation between the body size of toads and the number of prey ingested, a positive correlation between toad body size and prey size due to sexual size dimorphism, high overlap of dietary preferences, and concordance in the distribution of various prey types between males and females. Furthermore, males consumed small prey items in higher proportions than did females, but the opposite was found for medium-size prey, which suggests possible dietary niche partitioning in prey size rather than in taxonomical composition.

Rhinella atacamensis and Rhinella arunco are sister species which, together, are distributed from 25°S to 38°S in Chile. Until recently they were considered to be allopatric, with the dividing line around 32°S, but in 2007 a possible zone of secondary contact was found in the Estero Pupío (32°S). We investigated the species status of adult individuals of three localities along this creek using AFLP markers. Data were analyzed with a Bayesian method that allowed the identification of different types of hybrids in a population. In two of the localities in the lower part of the watershed, the majority of the individuals were identified as backcrosses of hybrids with R. arunco or first generation hybrids, although a few individuals were classified as pure R. arunco. This information, supplemented by mitochondrial sequences and reproductive observations in both the laboratory and in the field, shows that hybridization has been a recurrent phenomenon at these two localities. By contrast, in the third locality, higher in the watershed, we detected a certain amount of nuclear introgression of R. arunco in a population where only individuals with phenotypes and mitochondrial genotypes of R. atacamensis were found. Taken together, the genetic data of the three localities suggest that the hybrid zone is a hybrid swarm which is relatively extensive in the watershed of the creek. Identifying the causes of the apparent spatial segregation of the two species in the Estero Pupío will require additional information.

The boid genus Epicrates contains 10 species in the West Indies, several of which are listed as threatened or endangered, whereas the status of the others remains unknown. Little is known about Turks Island Boas (Epicrates chrysogaster chrysogaster), a subspecies of the Southern Bahamas Boa endemic to the Turks and Caicos Islands, and no published ecological studies exist for this subspecies. A long history of human habitation, greatly exacerbated by exponentially increasing development in the last several decades, appears to be threatening the remaining populations of these boas. However, a lack of basic ecological information is holding back conservation efforts. Here we report on the first multiyear ecological study of Turks Island Boas, focusing on an important population located on the small island of Big Ambergris Cay in the southeastern margin of the Caicos Bank. Encounter rates of up to 3.5 snakes per person-hour make this population especially easy to study. We captured 249 snakes, 11 of which were recaptures. We provide basic natural history information including size, color pattern, girth, body temperature, abundance, diet, activity, diurnal refuge selection, and population size. We also clarify the known distribution and discuss the conservation concerns of this species. This study fills a gap in our ecological knowledge of Bahamian boas and will provide important baseline data for the Big Ambergris Cay population of Turks Island Boas as this small island undergoes extensive development over the next several decades.

Recent studies predict that several lineages of tropical animals are at particular risk given current estimates of global climate change. Yet, much uncertainty exists on the effects of climate shifts in ectothermic species from cool temperate regions such as Patagonia. In this study, we focus on the impact of environmental temperature on growth, age at sexual maturity, and life-span of the Patagonian gecko Homonota darwini. Skeletochronological methods were used to assess the bone growth rates of individuals from three populations at different geographic and temporal scales: two populations from Chubut (warm site; 1941 and 2010) and one population from Río Negro (cold site; 1997–1998). Populations displayed similar bone arrangement and the growth patterns fit a von Bertalanffy curve. Three populations attained reproductive size at a minimum age of 3 yr, but at the cold site two specimens were shown to mature in 4 yr. We found no differences in juvenile growth rates in body size or bone zone width between juveniles of 1 to 3 yr of age from the 1941 warm site and the 2010 warm site. However, these traits appeared to be higher at these two warm sites than at the cold site, which is consistent with the climatic differences among the three localities. Our results suggest that higher temperatures positively affect growth, denoting that global warming might benefit H. darwini, especially the southern populations.

Understanding the specific habitat requirements of reptiles during different life stages or seasons is critical to conserving viable populations. Northern Pinesnakes (Pituophis melanoleucus) are one of the few species that spend the winter in underground hibernacula, which they excavate themselves. We report on 26 years (1986–2011) of monitoring Pinesnake use at seven hibernacula in the New Jersey Pine Barrens. Our goal was to determine the frequency of repeated use, number of snakes present by year, disruptions of hibernacula, and the relationship between number of snakes present and the probability of occupancy of each hibernaculum in successive years. The overall goal was to determine the importance of protecting known hibernation sites regardless of whether they appear occupied in a given season. These data suggest that, if no snakes are observed entering a particular hibernaculum over a limited time period, it does not mean none are there or that none will use it in successive years. The variability in use suggests not only that predation and human disturbance can result in nonoccupancy the following year but that environmental and temperature-related conditions force snakes to have alternative hibernacula to reduce risk and ensure survival. Pinesnakes are listed as threatened by the New Jersey Department of Environmental Protection for many reasons, including habitat loss. There is continued pressure from developers to destroy habitat during development, including critical hibernation sites. The long-term use of specific hibernacula, even with periods of low or no use, suggests that these resources should be protected to provide a matrix of available overwintering sites.

Sceloporus woodi (Florida Scrub Lizard) offers an excellent opportunity to contrast connected and fragmented habitats to determine how historical patterns influence genetic differentiation in fragmented habitats. We screened six microsatellite loci in S. woodi (N = 154) from seven sites at Archbold Biological Station, a large, connected scrub habitat where there is a potential for gene flow in spite of the low dispersal in S. woodi. We compared genetic differentiation of S. woodi in the connected scrub to that previously detected among a cluster of naturally fragmented scrub patches. We also performed simulations to determine how fragmentation would alter genetic differentiation in the connected scrub. Sceloporus woodi had modest, fine-scale genetic differentiation that followed isolation-by-distance and habitat structure in the connected scrub. There was less differentiation in the connected scrub than observed among the naturally fragmented scrub patches. Spatially explicit Bayesian clustering with TESS and BAPS identified two groups among the seven sites and θ_ST estimates revealed significant differentiation among sites (θ_ST = 0.052; P < 0.001). A positive relationship occurred between geographic distance and genetic differentiation (r = 0.226; P = 0.04). Limited dispersal likely has generated isolation-by-distance with a gradient of genetic differentiation among sites. When the geographic relationship among sites was considered, simulations indicated that fragmentation would tend to increase genetic differentiation immediately after fragmentation, yet fragmentation reduced genetic differentiation in some cases. Thus, historical patterns of genetic differentiation may play an important role in determining the population structure of a species after habitat fragmentation.

Natural refuges constitute a fundamental resource in the habitat of any given species. Consequently, the knowledge of those elements that are used as protection from predators is a priority for conservation. We studied the antipredatory mechanisms of an assemblage of sand dune lizards, determining whether refuge sites are random or whether particular types are chosen depending on their availability. We also compared the frequencies of the use of refuge sites with the use of perch sites by individuals at initial detection. Liolaemus multimaculatus used sites under rocks, either as refuges or as perches, and sites under sub-shrubs (Senecio bergii) and clump herbs (Spartina ciliata) as refuge only. Liolaemus gracilis used sites under creeping herbs (almost exclusively Panicum racemosum) and sub-shrubs (Senecio bergii) as refuge and perch sites more frequently than expected. Liolaemus wiegmannii only used sub-shrubs (mainly Melilotus indicus but also Achyrocline satureioides and Senecio bergii) both as refuge and perch sites. We show that lizards of Costa Bonita select certain types of native psammophytic grassland plants as refuge. Most of the plants used as refuge are also used as perch sites.

Los refugios naturales constituyen un recurso fundamental del hábitat de una especie. En consecuencia, el conocimiento de aquellos elementos utilizados como protección ante los depredadores, constituye una medida prioritaria para su conservación. Estudiamos los mecanismos antidepredatorios en un ensamble de lagartijas arenícolas, explorando si el uso de los refugios es al azar o si hay una selección de determinados tipos dependiendo de su disponibilidad. También se comparó la frecuencia de uso de sitios de refugio con los sitios de percha donde los individuos fueron detectados inicialmente. Liolaemus multimaculatus utilizó los sitios bajo roca, ya sea como refugio o como percha y sólo como refugio a sitios bajo subarbustos (Senecio bergii) e hierbas en mata (Spartina ciliata). Liolaemus gracilis utilizó más frecuentemente a lo esperado como sitios de refugio y percha a aquellos bajo hierbas rastreras (casi exclusivamente Panicum racemosum) y subarbustos (Senecio bergii). Liolaemus wiegmannii sólo utilizó subarbustos, tanto como sitios de refugio como de percha (principalmente Melilotus indicus pero también Achyrocline satureioides y Senecio bergii). Este trabajo demuestra que las lagartijas de Costa Bonita seleccionan determinados tipos de plantas del pastizal psamofítico nativo para reducir los riesgos de ser capturadas. La mayoría de estas plantas son sus principales sitios de percha.

We describe the external morphology and internal oral features of tadpoles of the torrent frog Hylodes magalhaesi from its type locality in southeastern Brazil. The tadpole can be distinguished from others of the genus mainly by the size of marginal papillae gap, the number and distribution of marginal papillae rows, and the number of submarginal papillae. The internal oral features of H. magalhaesi are similar to Hylodes charadranaetes; however H. magalhaesi can be distinguished from other species by the number and shape of buccal floor arena papillae and by the number of the prepocket papillae.

Microhabitat selection is critical to thermoregulation in ectotherms, particularly in small-bodied organisms for which low thermal inertia can impose rapid acquisition of thermal equilibrium with the environment. Although thermal microhabitat selection is often included in studies of niche partitioning among lizard species these investigations typically address only adult thermoregulation and, therefore, potentially neglect age classes in which thermal microhabitat selection could be especially consequential. We measured thermal time constants for juveniles of the lizard Anolis carolinensis and compared thermal microhabitat selection of this species with that of an invasive co-occurring congener, Anolis sagrei. In keeping with the exceptionally low mass of these lizards, heating and cooling rates were found to be extremely high and more similar to those of some insects than to other terrestrial vertebrates. On laboratory thermal gradients juvenile A. carolinensis tended to select warmer temperatures than A. sagrei, a pattern that is opposite to that observed for adults of these species. Because the rate of core temperature change was found to be an order of magnitude higher in juveniles than in adults and because the interspecific pattern of temperature selection is categorically different, these results suggest that investigation of juvenile anole thermoregulation could be of particular importance in developing an accurate characterization of resource partitioning among these model species.

Chemical contamination may influence host-pathogen interactions, which has implications for amphibian population declines. We examined the effects of four insecticides alone or as a mixture on development and metamorphosis of Pacific Treefrogs (Pseudacris regilla) in the presence or absence of the amphibian chytrid fungus (Batrachochytrium dendrobatidis [Bd]). Bd exposure had a negative impact on tadpole activity, survival to metamorphosis, time to metamorphosis, and time of tail absorption (with a marginally negative effect on mass at metamorphosis); however, no individuals tested positive for Bd at metamorphosis. The presence of sublethal concentrations of insecticides alone or in a mixture did not impact Pacific Treefrog activity as tadpoles, survival to metamorphosis, or time and size to metamorphosis. Insecticide exposure did not influence the effect of Bd exposure. Our study did not support our prediction that effects of Bd would be greater in the presence of expected environmental concentrations of insecticide(s), but it did show that Bd had negative effects on responses at metamorphosis that could reduce the quality of juveniles recruited into the population.

We studied the reproductive ecology of the gecko Phyllopezus pollicaris in a mountain environment in the Municipality of Diamantina, State of Minas Gerais, Brazil, from February 2005 to January 2006. The reproductive activity of P. pollicaris was cyclic, occurring from the end of the dry season to the end of the wet season. We found no relationship between female reproductive activity and long-term precipitation and temperature. Males exhibited sperm in their testes throughout the year, and their reproductive activity was not related to any of the climatic factors analyzed. Fat storage varied inversely with reproductive activity, and fat-body mass was large in females. All gravid females had a clutch of two eggs.

The analysis of mass and energy budgets provides critical insight for the modeling of both individual organisms and populations. Ectotherms in particular are closely tied to environmental variation because of thermal dependence of most physiological functions. We studied the effects of temperature on digestion and growth in 28 Timber Rattlesnakes (Crotalus horridus) from Arkansas, Mississippi, and Virginia. We conducted feeding trials in environmental chambers in a repeated-measures design to analyze the effects of three trial temperatures (20, 25, and 30°C) on digestion and growth. We found no significant temperature effect on passage times (average 12.36 days), apparent digestibility (average 87.5%), or metabolizable energy (average 80.6%) across the 10°C temperature range. There was an apparent temperature-dependent tradeoff in the allocation of mass and energy to growth in girth versus growth in length. Snakes allocated similarly to body mass at all three temperatures; however, growth in SVL increased significantly from 20°C to 30°C. These observations suggest that snakes at 20°C allocated to increases in girth, whereas snakes at 25°C and 30°C allocated increasingly to increases in body length. We estimated the metabolic cost of growth to be approximately 10.5 kJ g⁻¹ dry mass (95 % CI: 6.8–14.1 kJ g⁻¹ dry mass), which corresponds well with previous estimates in ectotherms.

Western Fence Lizards, Sceloporus occidentalis, are frequently parasitized by the malaria-causing protozoan Plasmodium mexicanum, reducing hemoglobin concentrations, increasing reliance on anaerobic metabolism, and elevating the cost of recovery. We examined the influence of malarial infections in Fence Lizards on aerobic capacity, blood metabolites, and cardiopulmonary activity following activity (<2 min of maximal activity) on a treadmill at 35.0 ± 1.0°C. Aerobic capacity was determined from resting and maximal oxygen uptake. Blood glucose and lactate were measured before activity and at 15 min intervals during 60 min of recovery. Heart rate and ventilation rate were determined from electrocardiograph tracings. Maximal aerobic capacity was over 35% higher in uninfected lizards compared to both malaria-infected lizards and anemic-uninfected animals. Malarial infection decreased lizard resting blood glucose levels, yet induced hyperglycemia during recovery; blood glucose levels were elevated by about 27% from resting in malaria-infected lizards after 60 min of recovery. Malarial infection significantly increased anaerobic metabolism during activity; blood lactate levels in infected lizards were elevated above those in uninfected animals for 45 min of recovery. Heart rate was limited severely in malaria-infected lizards following activity; mean heart rate was over 20 beats per minute lower (170 ± 6.7 vs. 193 ± 5.0) in infected lizards compared to uninfected animals. The major disruptions to recovery metabolism in malaria-infected lizards, glucose, lactate, and cardiac dysfunction, are similar to those reported for severe Plasmodium infections in mammals.

Autotomy of an appendage, especially the tail in lizards, can aid in escape from predators, but that assistance comes with associated costs. In previous studies, decreases in sprint performance often followed tail loss in lizards, and potential sexual differences following tail autotomy can provide evidence for the possible influence of sexual selection on performance in lizards. We measured the impact of tail autotomy on sprint performance in the lizard Uta stansburiana, a species that has frequent natural tail loss. Sprint performance was measured using both maximal sprint speed and average stride length. We examined the impacts separately for each sex, as this species is molded strongly by sexual selection, and tail autotomy is known to affect the social status of male and female subadult U. stansburiana differently. To check for sexual differences in sprint performance, we assessed both sexes with intact tails. Neither sprint speed nor stride length significantly differed between the sexes. Following tail loss, male performance was not affected; individuals maintained their previous maximal sprint speed and average stride length. However, females significantly decreased both maximal sprint speed and average stride length following tail autotomy. We suggest that tailless males maintain high speeds to escape predators because of greater conspicuousness due to sexual dimorphism and behavior, as well as for repulsion of rivals from their territories. Postautotomy females may adopt an alternate social role that does not require their prior sprint speeds. Sexual selection may have advanced this sexual difference in sprint performance after tail autotomy.

Envenomation by snakes of the genus Bothrops is characterized by local pain, systemic bleeding, tachycardia, acute renal failure, as well as swelling and redness caused by the enzymatic and proteolytic action of venom. The toxicological and histological effects of the venom of Bothrops itapetiningae, one of the smallest pit vipers in Brazil, were characterized using BALB/c male mice as models. Venom impacts on liver, kidney, and plasma enzymes that were evaluated at six concentrations. We observed lethality, toxicity, edema forming, and hemorrhagic symptoms such as polymorphonuclear infiltration, hydropic degeneration, and ischemic necrosis. Moreover, increases of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatise, and creatinine levels were observed in the presence of venom. We assessed LD₅₀, minimal hemorrhagic dose, minimal edematogenic activity, and platelet aggregation, improving our knowledge of B. itapetiningae venom toxic activity.

Widespread amphibian declines and habitat fragmentation, coupled with advancements in tracking, have sparked increased emphasis on studying movements and the use of terrestrial habitats by amphibians. Peñalara Natural Park, Sierra de Guadarrama, Central Spain, provides habitat for a number of amphibians that use upland sites. In response to increased pressure on habitat in this region by tourism, we used 4 months of radiotelemetry data for 17 adult Common Toads (Bufo bufo) to characterize the terrestrial movements, assess the factors influencing these movements, and determine the distribution and cover characteristics of summer refugia for these toads. We found that: 1) movements were most pronounced following the breeding season in June, and adults made movements of up to 470 m away from breeding sites, 2) movements were not influenced by basin size, climatic variables, or the sex of the individual, 3) the amount of terrestrial habitat used by toads ranged from 245 m² to 2.5 ha, and 4) within these areas toads most often used rock piles and juniper patches (Juniperus communis nana) as cover during the summer. Our study emphasizes the importance of considering terrestrial landscapes when developing conservation strategies, and we suggest that a buffer of minimal development extending 550 m from the shoreline of each natal pond be considered when conservation plans are developed for Common Toad habitat in Peñalara Natural Park.

The Gopher Frog, Lithobates capito, is an endemic to upland, fire-maintained pine forests on the Southeastern Coastal Plain and requires open, isolated wetlands for breeding. This species has experienced drastic population declines because of habitat loss and degradation and now occurs only in scattered populations in the southern United States. We tracked the post-breeding movements and burrow use of 17 Gopher Frogs in the Sandhills of North Carolina using radio telemetry. Nine frogs were successfully tracked to summer refugia; the other eight frogs shed their transmitters or were killed by predators or fire during migration. Frogs traveled 0.5−3.5 km (mean = 1.3 km) between the breeding pond and a summer refugium. The 3.5-km movement is substantially longer than has been reported for Gopher Frogs before. Our results suggest that an area of 3,739 ha (9,239 acres) around breeding ponds is required to provide summer habitat for Gopher Frogs. Eight of nine frogs used holes associated with the stumps of longleaf pines for their summer refugia, and we documented fidelity to particular stumps, with one frog traveling long distances from breeding pond to the same summer refugium during two consecutive seasons. Frogs only made major movements during rainy nights. Prolonged presence on the forest floor during post-breeding migrations exposed frogs to prescribed fires conducted in the spring. Prescribed burning within several kilometers of Gopher Frog ponds should be conducted after mid-May to reduce adult mortality.

We hypothesized that Palestine Saw-Scaled Vipers (Echis coloratus) select ambush sites that allow them to remain in a relatively cooler microclimate. During spring 2010, we identified the locations of 27 vipers in the Eilat Bird Sanctuary, Israel. Twenty-six (96%) of Vipers were recorded in 15 Salvadora persica, one (4%) in Zygophyllum dumosum, and none in Ochradenus baccatus. The temperature at the base of the S. persica was on average 6°C lower that in O. baccatus. We also found that the greater the apron radius of S. persica, the lower the temperature in the bush, and that bushes of S. persica occupied by vipers, have greater apron radius that those without snakes. We found that each of the snakes remained in the bush in which it was found during the whole three months of the study. We conclude that the cues used by E. coloratus for predicting future prey availability seem to be the structure of the microhabitat rather than prey odor. Our study is of conservation importance and enhances our understanding of habitat choice in this little-studied snake.

Amphibian decline is a well-recognized globally occurring problem. Hypothesized and demonstrated causes of decline are varied and include disease, contaminants, habitat loss, and climate change. Future research and management efforts may be further improved by understanding how different anthropogenic stress factors contribute to amphibian population declines for different species. I used a stochastic, density-dependent population model of the pool-breeding amphibian, Gastrophryne carolinensis, to explore the relative contribution of different simulated stress factors operating individually and in combination on a number of different life-cycle components. The simulations revealed that catastrophic reproductive failure (CRF) as may occur under climate-induced reductions in hydroperiod was a strong driver of extinction risk and that, in the absence of CRF, extinction risks were low (<1%) even under some reduction in recruitment and terrestrial survival for this species. When reductions in vital rates and CRF occurred together, extinction risks increased pointing to the importance of multiple factors as potential drivers of amphibian decline. The results presented here suggest that climate change-induced alterations in hydroperiod may have severe consequences for declines of some amphibian populations. Further, the presence of additional stress factors only serves to increase risk. In addition to the need for studies of stressor effects on components of amphibian life cycles, future research and conservation efforts should consider the interaction of stressors acting on the health of individuals (disease, pollution) and temporal variation in environmental factors such as hydroperiod.

Our objective was to examine breeding dispersal, burrow-use characteristics, and burrow habitat selection by Crawfish Frogs (Lithobates areolatus) in two distinct vegetation types (open grasslands and a mosaic of forest and transitioning grasslands) in southeastern Indiana, from March to August 2009 and 2010. We captured 14 frogs at their breeding ponds and tracked them to their burrows using radio telemetry. Once we identified their burrows, we compared habitat metrics at the burrows to random locations. We used an information-theoretic model selection approach to approximate the parsimony of logistic regression models comparing the habitat features of burrows to random, available sites. Frogs dispersed a straight-line average distance of 215 m and used an average of four burrows. They generally did not change burrows after June. Our top model included covariates for the number of burrows, canopy cover, and a site covariate. Our results suggested that habitat selection by Crawfish Frogs occurred hierarchically; in mixed grassland/forest habitats, they first selected areas with low canopy cover, and then selected areas with many available burrows. To manage habitat for Crawfish Frogs, we recommend preventing woody encroachment and reducing canopy cover in grassland areas occupied by Crawfish Frogs. Additionally, areas with a large number of burrows appear to provide the most suitable Crawfish Frog habitat.

Japanese Mamushi (Gloydius blomhoffii) has long been exploited for its medicinal value. We studied this snake's reproductive ecology on Hokkaido and assessed its vulnerability. We marked 299 individuals from 1999–2002 and kept 29 pregnant females in captivity until parturition. Pregnant females aggregated at gestation sites during summer and fall until just before parturition. Behavior suggestive of mating seasons was evident mostly in August and September. As expected, there was an apparent sex difference in body size in adults but not in neonates: females were larger than males. Consistent with previous reports, both neonates and adults were larger in Hokkaido than in southern Japan. The smallest pregnant female measured 44.8 cm in SVL, which was larger than values reported from southern regions. Offspring sex ratio was statistically equal: 88 males to 105 females. Litter size averaged 6.6 offspring. Longer females tended to produce larger litters and longer neonates. The proportion of pregnant to non-pregnant females, coupled with mark–recapture data, suggested that Mamushi females skip one or more years between reproductive bouts. Relative litter mass (RCM) was large (83% on average), and postpartum body condition was lower, especially so in females with larger RCM. Direct human-caused mortality was highest for pregnant females (70.2%), followed by non-pregnant females and then males. High adult mortality, particularly of pregnant females, raises a concern about population persistence, because Mamushi exhibit a slow life history. The tendency of pregnant females to aggregate at predictable locations further makes Mamushi populations vulnerable to human killing and exploitation.