An innate immune defense of frogs against microbial pathogens is secretion of antimicrobial peptides from skin granular glands. This study aimed to characterize the activities of skin antimicrobial peptides against seven different opportunistic bacterial pathogens associated with bacterial dermatosepticemia, a fatal infectious disease of frogs, including Aeromonas hydrophila, Chryseobacterium meningosepticum, Citrobacter freundii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, and Serratia liquefaciens and the bacterial saprophyte Lactococcus lactis. Natural peptide mixtures from African Clawed Frogs (Xenopus laevis), Green and Golden Bell Frogs (Litoria aurea), Southern Bell Frogs (Litoria raniformis), and Brown Tree Frogs (Litoria ewingii) were assayed for bacterial growth inhibition. Peptide mixtures from X. laevis, L. aurea, and L. raniformis inhibited the growth of C. freundii, K. pneumoniae, P. aerugionsa, and L. lactis with the peptide mixture of X. laevis having the strongest inhibitory effects on these pathogens and also inhibiting the growth of C. meningosepticum. Similarly, X. laevis produced more active peptides per unit surface area than did L. aurea or L. raniformis. The peptide mixture of L. ewingii was not active against any pathogen. Three pathogens abundant in skin microbiota including A. hydrophila, P. mirabilis, and S. liquefaciens were resistant to peptide mixtures of all tested species. Therefore, although the activities of skin peptides could control several different opportunistic pathogens including C. freundii, K. pneumoniae, P. aerugionsa, and C. meningosepticum and the saprophyte L. lactis, it is suggested that some opportunistic pathogens such as A. hydrophila, P. mirabilis, and S. liquefaciens may have coevolved to resist skin peptides.

Chemical communication is important in aquatic environments, particularly where visual and acoustical signals are limited. Both larval (tadpole) and adult anurans (frogs and toads) use waterborne chemical signals for many activities. Adult anurans commonly rely on acoustical communication for sex recognition and mating; however, a growing body of evidence suggests that anurans also may use aquatic sex pheromones for localization of potential mates. We provide an overview of how the anuran nasal cavity reorganizes during metamorphosis from the larval to the adult stage. Also, we focus on the behavior of reproductive anurans in response to chemical information detected by olfaction of waterborne chemical cues. Overall, we synthesize the current literature on anuran sex pheromones and chemical communication in the aquatic environment.

A new species of Ctenosaura is described from the Pacific versant of southeastern Honduras (Departments of Francisco Morazán and Choluteca). This species occurs in a restricted area between the ranges of Ctenosaura flavidorsalis (southwest Honduras, El Salvador and southeastern Guatemala) and Ctenosaura quinquecarinata (Nicaragua and Costa Rica). The new species differs from C. quinquecarinata, Ctenosaura oaxacana, and C. flavidorsalis in several scalation and osteological characteristics and coloration pattern. The suggested phylogenetic relationships of the new species are ((C. flavidorsalis Ctenosaura sp. “southeastern Honduras”) (C. quinquecarinata C. oaxacana)). The specimens of the new species were mostly found in hollow trees and branches no more than 2 m above the ground. The habitat was dominated by shrub and tree vegetation. This lizard feeds mainly on young leaves and insects. Local people occasionally hunt the ctenosaur for food and consider it to have become rarer in the last two decades, primarily because of habitat loss.

Knowledge of habitat preferences by an invasive species provides a theoretical background for habitat management decisions. We used stepwise logistic regression to develop probabilistic models predicting the presence or absence of the postmetamorphic American Bullfrog (Lithobates catesbeianus) on Daishan Island. We found American Bullfrogs in 38 of 102 searched quadrats. Modeling indicated American Bullfrogs preferred permanent still water, such as large reservoirs and ponds. There was also a negative correlation between the presence of American Bullfrogs and the abundance of native frogs, suggesting that American Bullfrogs either represent a threat to native frogs or preferentially colonize sites where native frogs are rare or absent. This study provides a foundation on which to develop initial strategies to manage American Bullfrogs on the island and to assist in forecasting the areas suitable for invasion by American Bullfrogs in the region.

A new species of brachycephalid frog is described from São Luís do Paraitinga, in the Atlantic Rain Forest of São Paulo State, southeastern Brazil. The new species is characterized by male SVL  =  10.8–12.1 and female SVL  =  12.6–14.0 mm; and general color orange with dorsal reddish irregular markings, lateral surfaces with small dark brown spots, and belly with brownish spots and small dots. Comparisons with other brachycephalid species and osteological data are provided.

The San Marcos salamander (Eurycea nana), endemic to the headwaters of the San Marcos River, is federally threatened because of its restricted range and threats to its habitat. Captive propagation efforts for E. nana were initiated in 1996 to maintain a captive population for restocking in the event that E. nana becomes extinct. We surveyed DNA sequence data for a mitochondrial and a nuclear gene region (ND4 and rag1) and 281 AFLP markers to obtain baseline data on the level of genetic diversity across the known range of E. nana and to test for population subdivision within its restricted range. Next, we compared levels of genetic variation between E. nana in the wild and captive-born individuals from the captive population to assess the efficacy of the captive breeding program. We investigated inbreeding in the captive population by testing for deviations from Hardy-Weinberg equilibrium at the rag1 locus for captive-born individuals. The level of genetic diversity detected in wild E. nana was similar to that of other Eurycea populations in central Texas, and we found no evidence of population structure across the range of E. nana. The surveyed captive-born E. nana contained reduced genetic diversity at some loci, but similar genetic diversity at others relative to the wild, and there was no evidence of inbreeding within the wild-caught individuals that sired these captive-born individuals. The data we have obtained regarding the level of genetic variation in wild E. nana and in the captive population will provide baseline information for this species.

Pseudis platensis, like Pseudis paradoxa, is a Neotropical aquatic frog with a giant tadpole. Despite being one of the few anuran species whose larvae grow larger than adults, knowledge of its larval development is limited to prometamorphic stages. This study describes qualitative and quantitative variation through P. platensis larval development, including descriptions of various traits (lateral line, oral disc, vent tube, limbs) and their transformations during metamorphosis. We found similarities with the development of other anurans at larval stages up to the end of prometamorphosis but not with their metamorphic stages. For this species, we described key features to characterize 13 ontogenetic stages as follows: four for prometamorphic larval morphologies, eight stages covering metamorphic changes, and one defining the posmetamorphic adult stage. At the end of prometamorphosis, tadpole body size in P. platensis is similar to adult size, but the tail shows extra development. Unlike most anurans, the disappearance of two larval traits (i.e., vent tube and tail) is delayed until later in metamorphosis. Larval development of P. platensis exhibits unique features not reported for other anurans and offers a model to study developmental and evolutionary aspects of anuran metamorphosis.

It is well documented that sexual selection acts on morphological differences between individuals and can lead to sexual dimorphism in species with male combat and female choice. However, the effect of sexual selection on the evolution of morphological traits is poorly understood in species with scramble competition in which males race for access to females during a brief pulse of breeding activity. Because male access to females may be more random in scramble mating systems, male morphological traits may not strongly influence mating success. To investigate the influence of sexual selection on male morphology in a species with a scramble mating system, we collected detailed morphological measurements from male and female Columbia Spotted Frogs (Rana luteiventris), which have an extreme scramble mating system. Male Columbia Spotted Frogs have enlarged thumb (nuptial) pads and muscular forearms, which may help them grasp females. As predicted, we discovered that males found in amplexus with females had proportionately larger nuptial pads and thicker forearms than did unpaired males, but mating success was not related to overall body size. Although many single males attempted to dislodge males already in amplexus with females, no attempted takeovers were successful. Therefore, we suggest that the advantage of thick forearms and large nuptial pads occurs during the initial phase of securing a female when she first enters the breeding area. These findings suggest that sexual selection may influence morphology even in a species with scramble mating.

We examined morphological variation in tooth structure in four populations of garter snakes (genus Thamnophis) with diverse feeding habits and tested the hypothesis that morphological homoplasy evolved in the malacophagous predators Thamnophis ordinoides and Thamnophis elegans terrestris. Although long, slender teeth are typical in Neotropical colubrid snake species that prey on slugs and snails, this morphological feature did not occur in T. ordinoides and T. e. terrestris relative to closely related garter snakes (the diet generalist Thamnophis elegans elegans and piscivore Thamnophis couchii). However, we did find pronounced posterior ridges located on the posterior maxillary teeth in the two slug predators but not in the generalist feeders. The evolutionary origin and functional advantage of these ridges has yet to be identified. The fish specialist T. couchii has many morphological features characteristic of adaptations for piscivory, such as long, sharper teeth and elongated mandible bones.

The increased encroachment of humans into natural areas is typically viewed as stressful for many wildlife species. A common stress response of many animals, including snakes, is the elevated release of the adrenal hormone, corticosterone. To test whether human encounters elicited a stress response in snakes, we monitored the levels of circulating corticosterone in free-ranging Cottonmouths (Agkistrodon piscivorus) during staged interactions. When exposed to a high-level disturbance (i.e., capture and confinement in a bag) for 30 min, Cottonmouths exhibited a significant corticosterone stress response as predicted. This response was four times that of the control treatment (i.e., immediately bled snakes) and shows that Cottonmouths exhibit strong corticosterone responses to confinement. Conversely, blood corticosterone values for low-level disturbance (i.e., nearby human presence for 30 min) did not differ significantly from the control treatment. The lack of a strong stress response to low-level disturbance indicates that Cottonmouths possess a seemingly adaptive mechanism of not being overly alarmed by the mere presence of a potential predator. This suggests that the occasional foot-path encounters humans commonly have with snakes may not be stressful for some snake species.

Takydromus sikkimensis was named in 1888 by A. Günther on the basis of an 1872 description of grass lizards from Sikkim by F. Stoliczka. Subsequent workers have not considered this species valid and have even doubted the occurrence of Takydromus in Sikkim. We confirm the occurrence of grass lizards in the lower Teesta valley of Sikkim. These are consistent with the description of T. sikkimensis and are distinguishable from all other congeners on the basis of having 12 rows of enlarged ventral scales across midbody, three pairs of chin shields, 3–6 femoral pores on each thigh, and color pattern lacking stripes, spots, or ocelli. Because the type specimens are lost, and because there has been a persistent confusion regarding the identity, and even the existence, of the taxon described by A. Günther as T. sikkimensis, we designate a neotype to stabilize the use of the revalidated name.

We evaluated the diets of three sympatric anuran species, the native Northern Pacific Treefrog, Pseudacris regilla, and Foothill Yellow-Legged Frog, Rana boylii, and the introduced American Bullfrog, Lithobates catesbeianus, based on stomach contents of frogs collected at 36 sites in 1997 and 1998. This investigation was part of a study of mercury bioaccumulation in the biota of the Cache Creek Watershed in north-central California, an area affected by mercury contamination from natural sources and abandoned mercury mines. We collected R. boylii at 22 sites, L. catesbeianus at 21 sites, and P. regilla at 13 sites. We collected both L. catesbeianus and R. boylii at nine sites and all three species at five sites. Pseudacris regilla had the least aquatic diet (100% of the samples had terrestrial prey vs. 5% with aquatic prey), followed by R. boylii (98% terrestrial, 28% aquatic), and L. catesbeianus, which had similar percentages of terrestrial (81%) and aquatic prey (74%). Observed predation by L. catesbeianus on R. boylii may indicate that interaction between these two species is significant. Based on their widespread abundance and their preference for aquatic foods, we suggest that, where present, L. catesbeianus should be the species of choice for all lethal biomonitoring of mercury in amphibians.

As remaining longleaf pine forests become increasingly fragmented, wildlife management becomes a daunting task, especially for rare and relatively unstudied taxa such as the Black Pine Snake (Pituophis melanoleucus lodingi). Appropriate management for P. m. lodingi depends on our understanding of the ecology of this subspecies; consequently, there were two main objectives of this study: to address questions of spatial ecology for P. m. lodingi on a rangewide scale; and to employ small mammal trapping within home ranges of telemetered snakes to investigate the relationship between prey density and spatial ecology. Pituophis melanoleucus lodingi exhibited large home ranges (MCP, Minimum Convex Polygon home ranges, were 92–396 ha), frequently crossed roads, and average (nonzero) movement distance for these snakes was 338 m per location event. Core home ranges of telemetered P. m. lodingi were characterized by significantly greater abundances of hispid cotton rats (Sigmodon hispidus) and significantly higher total small mammal biomass. By better defining the relationship between spatial ecology and prey dynamics for P. m. lodingi, land managers will be better equipped to manage and conserve remaining populations of this longleaf pine specialist.

Although parental care is generally rare among reptiles, nest-guarding occurs in some species and is usually attributed to defense against nest predation. Nest-guarding also occurs in the Tuatara (Sphenodon punctatus), but nest predation on rodent-free islands does not appear to be a significant threat to nesting success in this species. We studied a population of colonially nesting Tuatara on rodent-free Stephens Island, New Zealand, over four years and tested the hypothesis that female Tuatara guard their nests to defend them from excavation by conspecific females. We located 73 nests for which females could be assigned based on observations during oviposition. Nearly 25% of these nests were subsequently excavated by another female, but only 56% of the nests were guarded by the females that constructed them. We found a trend where guarded nests were less likely to be excavated than unguarded nests. Females were more likely to guard their nests, and guarded nests for longer, as the activity of other females on the date of oviposition increased. Nest-guarding in Tuatara appears to be adaptive in that it tends to reduce the likelihood of nest excavation by other females, but social interactions may affect females' propensity to guard, because guarding behavior was influenced by the activity of conspecifics at the time of oviposition.

We used principal component analysis and logistic regression to evaluate the effect of 11 pond water quality variables on the presence and absence of Great Crested Newts (Triturus cristatus) in a cluster of 29 ponds in south-central Sweden. Variables of importance for the patterns observed were comprised into four principal components. Using logistic regression analysis and Akaike's Information Criteria (AIC) we found that the best model explaining the distribution of Great Crested Newts included three of the principal components. Temperature and nutrient levels (nitrogen and phosphorus) were important in distinguishing between ponds with and without Great Crested Newts, whereas other physical variables were less important. Ponds with newts had higher temperatures and nutrient levels than ponds where the species was absent. Our results also suggest that the Great Crested Newt selects ponds with low nutrient levels for breeding, whereas they may be present in ponds with higher nutrient levels. Although this study was performed in a single area with a limited sample the results raise several issues of general importance for the management and conservation of Great Crested Newts in pond landscapes.

We studied body-size and sex-dependent variation in the diet of Rhinella arenarum in a wetland of San Juan, Argentina. We hypothesized that prey size would be positively correlated with toad size and that the guts of larger toads would contain fewer prey items. Toads from this population eat primarily ants and, secondarily, beetles, indicating a feeding strategy that is intermediate between specialist and generalist. This feeding strategy may be influenced by prey availability. Contrary to our expectation, prey size was not related to toad body size, and the relationship between the prey number and toad body size was positive. Our findings, coupled with similar diet studies of toads, suggest geographically widespread phylogenetic conservatism in the diet of bufonids.

To construct an ethogram of Sacalia quadriocellata and introduce coding system into chelonian behavior research for quantitative comparison, 15 captive S. quadriocellata (eight females and seven males) were observed for one year using a digital surveillance system, and an ethogram constructed. Fourteen types of states and 84 types of events were recorded. Seventy-five behaviors were defined and described, and these were classified into eight categories of behavior: Feeding, Elimination, Conflict, Alert, Rest, Locomotion, Courtship, and Other. Feeding, Elimination, and Locomotion are frequent behaviors, whereas Conflict and Other behaviors are seldom observed. Mainly, this may be caused by environmental conditions that eliminate these plastic behaviors (e.g., Conflict and Other behaviors) and keep the nonplastic behaviors (e.g., Feeding, Elimination, and Locomotion). Finally, the comparison between S. quadriocellata and other chelonian species indicate that the behavioral patterns are similar on the whole, but the Conflict behaviors of S. quadriocellata are milder than other species.

The introduced Cane Toad Rhinella marina has recently expanded its range into the monsoonal north of Australia near Darwin, Northern Territory. Aggregated toads were collected toward the end of the prolonged dry season from an isolated and localized occurrence of moist soil, where they were observed in typical water absorbing postures. Water potential of the moist soil (−31 kPa) was sufficient that toads could extract liquid water via the ventral pelvic patch, but surrounding dry soils with water potentials lower than −8,000 kPa could not be used as moisture sources. High mean plasma (358.5 mOsm kg⁻¹) and urine (353 mOsm kg⁻¹) osmolality values are indicative of dehydration, and high urea concentrations in plasma (109 mmol L⁻¹) and in urine (237 mmol L⁻¹) demonstrate accumulation and retention of waste nitrogen. All parameters differed markedly from those of fully hydrated toads in the laboratory and from active animals collected in the wet season. The urine osmolality of wet season individuals (mean ± SD: 118.9 ± 76.4 mOsm kg⁻¹) was intermediate compared to the laboratory hydrated animals and the dry season sample, but plasma osmolality and urea concentrations were similar to fully hydrated toads. Differences in body fluid osmolality reflect the availability of soil and surface moisture in the environment in the wet and dry seasons. The need to access residual moisture sources during the late dry season is likely to limit Cane Toad movement and resulted in the aggregation of toads at the rehydration site. This enforced aggregation potentially facilitates effective control of toads at a local scale.

The consistency of a trait's expression within individuals reflects both its maximal possible heritability and that trait's susceptibility to the influence of temporal variation in environmental conditions. A lack of repeatability in reproductive traits may also result if there are ontogenetic changes in female reproductive effort. In a decade-long study, we collected data on the reproductive traits (including female SVL, female postpartum condition, litter size, total litter mass, mean offspring mass, and birth date) of free-ranging Pigmy Rattlesnakes in central Florida. We captured and held the study snakes in field enclosures for several weeks before parturition each year. A total of 24 females produced two or more litters during the course of the study. We determined the repeatability for each reproductive trait. Our results indicated that four of the six reproductive traits had high and statistically significant repeatability despite annual variation in environmental conditions. A lack of growth in adult Sistrurus miliarius and the ability of females to skip reproduction in some years appear to foster the high repeatability of reproductive traits. Our research and previous studies indicate that many, but not all, reproductive traits in female snakes are highly repeatable. The repeatability of a few traits, particularly post-partum female condition, is likely to depend strongly on the reproductive mode of the species.

Liolaemus barbarae was recently described from northern Chile. However, the character states used to distinguish this species from Liolaemus puna are not exclusive. We reassessed the character states used for the diagnosis of L. barbarae and compared these with data from the type series and additional specimens of L. puna. We found identical ranges or broad overlap in character states between the two species. We conclude that L. barbarae is a junior synonym of L. puna.

Males of the glass frog Hyalinobatrachium valerioi engage in diurnal and nocturnal attendance of egg clutches. To study the effect of parental care on embryonic survivorship, we conducted a male removal experiment and measured embryonic survival rates on day 4, 8, and 12 after oviposition in attended and unattended clutches. Embryonic survivorship was significantly higher in the control group than in the male removal group but decreased with time in both groups. Arthropod predation accounted for most of the mortality in both groups. Desiccation of clutches only occurred in unattended clutches. We hypothesize that egg attendance in H. valerioi increases embryonic survivorship by deterring egg predators and preventing desiccation.

Descriptions of the advertisement call are provided for three species of arthroleptid frogs from Malawi. The call of Arthroleptis reichei consists of the irregular repetition of one single whistling note with a frequency range of 1,600–4,000 Hz and a dominant frequency of 3,400–3,500 Hz. Although pulses are not clearly recognizable, notes show an evident subunit structure. The call of A. stenodactylus consists of the regular repetition of one single unpulsed whistling note with a frequency range from 2,700–4,900 and a dominant frequency of 3,200–3,400 Hz. The call of A. xenodactyloides consists of the regular and virtually endless repetition of one single clearly pulsed note with a frequency range of 4,900–7,500 and a dominant frequency of 6,300–6,500 Hz. On the basis of the available published data, two different call patterns are preliminarily recognizable in south and eastern African species belonging to Arthroleptis: (1) the repetition of one single unpulsed whistling-like note at low-medium (1,600–4,900 Hz) frequencies; and (2) the repetition of single pulsed cricket-like note at medium-high (4,600–7,500 Hz) frequencies.

The treefrog Hypsiboas bischoffi is endemic to southern and southeastern Brazil occurring in submontane and montane areas of the Brazilian Atlantic Forest. Here, we focus on geographic variation in morphological traits of H. bischoffi by analyzing the distribution of two distinct color pattern forms (striped and nonstriped) to examine the hypothesis that color pattern is polymorphic within populations throughout its range. We additionally describe variation in several morphometric traits and examine their association with either color pattern or environmental gradients across the range. Our results show that the two color pattern forms are parapatric, with the striped and nonstriped forms occurring in the northern and southern parts of the species range, respectively. The two forms were not observed to co-occur, but nonstriped individuals appeared to present somewhat intermediate color patterns near the putative contact zone between the two forms. Multivariate analysis of morphometric variation showed that variation in body size explains most of the observed variation, but neither body size nor further morphometric variation was associated with color pattern or geographic distance between populations. Body size appeared instead to be associated with local levels of summer precipitation. The geographic differentiation pattern in H. bischoffi is apparently concordant with those observed for a few other codistributed organisms in the Brazilian Atlantic Forest.

The previously unreported tadpole of Leptopelis karissimbensis, an endangered treefrog from Rwanda, is described. Tadpoles were collected, photographed, measured, and examined for standard metrics of tadpole morphology. Larvae of L. karissimbensis resemble other tadpoles in the genus Leptopelis in being muscular, elongate, and eel-like. The lateral tooth row formula for L. karissimbensis is 4/3. In late stage larvae, tadpoles of L. karissimbensis exhibit a prominent white spot below the eye. Larvae of this species were often abundant in suitable habitat at approximately 2,800 m in elevation. Larval habitat for L. karissimbensis includes seasonally flooded marshes, forest pools, and permanent ponds in the Virunga Mountains, the only known range of this species.