Predator–prey interactions are complex relationships between both participants. Although many food items are available in the environment for a frog, it can choose to feed on one item instead of another, depending on several aspects of the prey, such as size, availability, abundance, mobility, and palatability. In this study we compared the frequency of each food item we observed in stomachs of the frog Chiasmocleis leucosticta with the availability of leaf litter arthropods we collected at the same place and time that of the frogs through Ivlev's electivity index. We verified that the electivity for ants and mites as food items in the diet of the population from Reserva Florestal de Morro Grande is an actual preference. Chiasmocleis leucosticta seems to elect smaller sized genera, such as Solenopsis and Pheidole, and avoid bigger and more aggressive ants, such as Pachycondyla, Camponotus, and Odontomachus. Also, we suggest that for C. leucosticta or even for other Microhylidae there is reason to believe that alkaloids are obtained as part of the diet; related studies on the biochemistry of this family, genus, and species are encouraged.

The semiaquatic snake Erythrolamprus miliaris has a wide distribution in cis-Andean South America and is often locally abundant. Nevertheless, there is still comparatively limited information available on its ecology. In the present study, we analyzed the diet of E. miliaris in five different regions along the Atlantic Forest domain in eastern Brazil, based on the stomach contents of specimens deposited in scientific collections. Overall, only 10.2% of the stomachs contained identifiable food items, the most frequent of which were fishes and postmetamorphic anuran amphibians (present in 41.8% and 53.7% of adult stomachs, and 17.9% and 75.0% of juvenile stomachs, respectively). Diet composition was fairly similar among populations, indicating a low geographic variability in the species feeding habits. Our data suggest that younger snakes feed mainly on anurans, tending to consume more fishes as they grow larger. Consumption of toads of the genus Rhinella indicate that E. miliaris is resistant to bufonid toxins, as are other members of the tribe Xenodontini.

Ecologists have a long-standing interest in the size of animal home ranges, including those of lizards, but studies on females are relatively rare and often do not take into account possible space use changes in relation to the breeding cycle. We mapped locations of female Eastern Water Dragons (Intellagama lesueurii) daily, during the 2009 and 2016 breeding seasons in relation to reproductive status. Home ranges of all females bordered water and overlapped with areas used by other females. Average home range area was similar between 2009 and 2016, and home range size was not correlated with female size. Six surviving females used part of the same areas in both years. The average ratio of home range area to female size (standardized to linear dimensions) in Water Dragon females was only 13.6% that of 25 other large lizard species, and only 10.6% of estimates during and outside of the breeding season in another urban Water Dragon population. In our population, 38% (25 of 65) made temporary (1 d) departures from their usual home ranges. Palpation revealed that ripening eggs were present prior to departure but absent when females returned, and two of these females were observed digging nests during migrations. Short-term egg-laying migrations may reduce intergenerational competition resulting from strong philopatry in female Water Dragons. Our results reveal how repeated observations of individuals throughout critical periods, such as during the breeding season, can reveal subtle details in use of space that are likely important for the fitness of individuals.

The Rough Greensnake, Opheodrys aestivus, is a moderately sized, semi-arboreal snake broadly distributed throughout eastern North America. Although numerous taxa with similar distributions have been shown to comprise multiple species, O. aestivus has not been examined in a detailed phylogeographic context. Here, we use Sanger-sequence data (one mitochondrial, three nuclear loci) for samples from throughout the distribution of O. aestivus to elucidate phylogeographic patterns in this species. We combine this with ddRADseq data for a subset of samples to test patterns on a more genomically comprehensive scale. In both data sets, we find strong support for three deeply divergent clades within O. aestivus: peninsular Florida, central Texas, and a Main clade comprising the rest of the distribution. Estimates of divergence time suggest that the central Texas and Main clades diverged ∼1.3 million years ago (mya), while the peninsular Florida clade diverged from other lineages ∼2.9 mya, and these lineages diverged from the sister taxon, O. vernalis, ∼6.4 mya. The divergence of peninsular Florida or central Texas populations is not unique among squamates, nor is low levels of divergence from the Atlantic coast to eastern Texas, but this combination of patterns is unusual and yields important insight into the biogeography of North American biota. Further, our approach helps illustrate how dense geographic sampling with limited genomic sequencing can be used as a guide for the selection of samples to test phylogeographic patterns comprehensively. We conclude that elevating O. a. carinatus to species status may better describe the diversity of this genus.

At a field site in northeastern New York during a 40-yr study, we measured the body sizes (total length, snout–vent length [SVL], mass) in three intrinsic groups of adult Crotalus horridus: nongravid (N) females, gravid (G) females, and males. We argue that a bounty system in effect for 75 yr caused a probable decline of the largest animals. After this lengthy period of exploitation, we observed that body sizes began to increase. Across 4 decades, the three intrinsic groups were significantly larger in the final decade (2009–18) than in the first decade (1979–88), stabilizing at a mean body mass of »710 g in N females, »870 g in G females, and »1,200 g in males. Mean SVLs of N females (94.1 cm) and males (111.0 cm) in the final 3 decades were significantly larger than their SVLs in the first decade. The body condition index (BCI) increased over time, and the intrinsic groups differed significantly in mean BCI: N females (-0.0764), G females (0.0146), and males (0.0899). Among recaptured snakes, wide fluctuations of body mass were not uncommon as most snakes experienced annual losses as well as gains. Geographic variation in body size of C. horridus is illustrated by comparing our New York population with a northern population (Massachusetts) and a southern population (Virginia). Across the species' range, we suggest that body size could be associated primarily with prey size. Because many populations of C. horridus are slow growing and long lived, correlated effects of exploitation on body size may negatively affect the snakes' reproductive biology and longevity.

For many turtle species, life history traits such as body size, age at maturity, and somatic growth rate can vary among individuals and habitats and between the sexes. Therefore, it is important to consider factors that may influence growth when modeling (somatic) growth for turtles. Long-term capture–mark–recapture studies lend themselves to studying somatic growth in turtles due to the repeated measurements of individuals over time. We used a long-term dataset to examine growth patterns of philopatric Diamondback Terrapins (Malaclemys terrapin) on Kiawah Island, South Carolina, USA. We used a hierarchical three-parameter von Bertalanffy model to estimate individual growth of 44 female and 36 male Diamondback Terrapins that were each captured 3–17 times between 1983 and 2019. Sex and site (i.e., tidal creeks) were included as second-level model effects. Mean maximum asymptotic size (plastron length; L _∞ = 173.4 mm for females and L _∞ = 104.4 mm for males) and mean growth coefficients (K = 0.28 for females and K = 0.61 for males) varied between sexes. Growth variability among individuals was high, ranging from 23 to 56% within species for different parameters, suggesting that models not accounting for individual variability would be pooling dissimilar information. Site was a significant covariate for male growth, but not female growth. Understanding how Diamondback Terrapin somatic growth varies within a population may inform habitat quality as well as population health and vulnerability to anthropogenic stressors. Our model can serve as a comparison for other Diamondback Terrapin populations and provide more detailed information for demographic models that can be used in conservation decisions.

As adult turtle mortality increases as a result of anthropogenic threats, understanding the survival of younger age classes may help mitigate population declines. We radiotracked hatchling Eastern Box Turtles (Terrapene carolina carolina) through the first year of life in a Michigan population, located on the northern edge of their range. We monitored 60 hatchlings for between 2 and 333 d and estimated annual survival using known-fate survival estimates. From 2013 to 2015, 14 hatchlings (23%) were depredated, 19 hatchlings (32%) died because of exposure, and 2 hatchlings (3%) were crushed by motor vehicles. Survival decreased through the first year of life with a drop in survival probability from nest emergence in the autumn, before it reached 50% during overwintering (day 50 = 0.503; SE = 0.067), then again decreased with spring emergence and ending with 0% survival (day 333 = 0.0). Hatchlings that emerged in September survived up to 107 d longer than hatchlings that emerged in October, and larger hatchlings had a significantly higher probability of survival over smaller individuals. No small hatchlings survived through overwintering, whereas large hatchlings had a 0.82 (±0.095 SE) survival probability 228 d posthatching. Threats to a species survival at the limits of its range are often different from those faced by populations centrally located within the range. Thus, studies should be conducted across the Eastern Box Turtle's range to determine how survival probabilities vary in populations experiencing different environmental conditions.

Among amphibians, the fossorial habit is an evolutionary strategy to maintain their niches along space and time, avoiding hostile climate conditions. The fossorial frog Lepidobatrachus llanensis has evolved in temperate regions, adapted and distributed in arid subtropical environments, and is divided into two well-defined and isolated populations (northern and southern). In this study, we analyze if these two populations have adjusted their activity patterns (i.e., feeding and reproduction) as a strategy to retain their ecological niche characteristics along a semiarid latitudinal gradient. We modeled and characterized the ecological niches via Euclidean distance to the ecological niche centroid of the entire species under the false premise that the two populations are equally active throughout the year (i.e., annual niche). Then, we repeated the exercise considering the niches for the two populations (by estimating their real seasonal niche activity). We also performed comparisons between both populations via a similarity test. Our results suggest that both populations are active in similar climatic conditions but in different (dissociated) temporalities, suggesting that seasonal activity in fossorial species is a strategy to conserve their climatic niche in two different geographical areas across the year.

The Javelin Sand Boa, Eryx jaculus, is reported to be a predator of mammals, lizards and their eggs, and occasionally of birds and invertebrates, but data on its diet are scarce and fragmentary. Here we describe some aspects of the feeding behavior of E. jaculus on the Mediterranean island of Sicily. A total of 132 individual snakes were examined. Prey remains were found in 43% of them, both in their feces (82.5%) and gut contents (17.5%). The number of snakes observed and their feeding rate decreased in August, probably as a result of the relatively higher temperatures. Feeding rate increases were observed in adult females in September, perhaps to enhance body reserves before hibernation. The overall prey spectrum is dominated by small mammals, with a frequency of occurrence of 71.4%, but also consisted of lizard eggs (30.2%) and lizards (7.9%). Lizards seem to be occasional prey, and our frequent detection of ingested autotomized tails suggests E. jaculus has low efficiency as a saurian predator. We observed a relationship between prey type and snout–vent length of the snakes. Lizard eggs are most frequently eaten by smaller snakes, which could be linked to gape size ontogenetic variation. We found differences in the prey spectrum between sexes and age classes. Our results indicate that juveniles, adult males, and females seem to adopt different foraging strategies. Females probably adopt ambush predation on small mammals, while juveniles are active foragers of lizard eggs. Adult males appear to be slightly more versatile predators, consuming both types of prey, probably because of their high mobility rates during the mating period.

Reproductive strategies are an essential component of invasion ecology that influence invasion success and rates of population growth. Burmese Pythons (Python bivittatus) are large constrictor snakes that were introduced to the Greater Everglades Ecosystem of southern Florida, USA, from Asia. Since their introduction, these giant constrictors have spread throughout wetlands of southern Florida while increasing in abundance and causing declines in the native species upon which they prey. Multiple paternity in reproduction could facilitate invasion success by increasing the genetic diversity produced within each reproductive event. We used Diversity Arrays Technology genome-wide genotyping to assess multiple paternity in the progeny of wild Burmese Pythons in Florida. We analyzed >4,000 single nucleotide polymorphisms from 153 neonates belonging to 4 clutches collected in southwestern Florida. Complementary hierarchical and K-means clustering analyses of the genetic distances within clutches revealed that three clutches were each fertilized by two sires, with a fourth fertilized by a single sire. The proportions of offspring attributable to each sire within multiple paternity clutches ranged from nearly even to highly skewed. Analysis of multivariate dispersion showed significantly increased genetic variability in the multiple paternity clutches. These results improve our understanding of the reproductive strategy and invasion potential of a giant constrictor with significant ecological impacts.

Limb-reduced and limbless scincid lizards pose problems in untangling their relationships because of a strong tendency toward convergent evolution in which functional characters mask phylogenetic history. Their often small size makes cranial characters difficult to study, and collections of such species are often small and patchy because of their cryptic behavior. One such genus, Anomalopus (Sphenomorphinae), currently includes seven species of reduce-limbed and limbless skinks that occur in tropical and subtropical habitats in eastern Australia. The discovery of previously unreported populations of limbless skinks assignable to Anomalopus has prompted our revision of the morphology and systematics of this genus. We report new DNA sequence data and new morphological data by using X-ray micro-computed tomography scanning that corroborate published molecular data on sphenomorphine phylogeny, leading us to propose a new generic arrangement that recognizes the species of Anomalopus as belonging to three genera. The newly discovered populations represent two new species currently known from only three small and disjunct areas. We review the osteology of the three genera of the former Anomalopus, finding new characters and variable patterns of interspecific and interclade variation. The same morphological characters are modified in every limb-reduced sphenomorphine clade, but to differing degrees and in different combinations in each.

The Gray Fossil Site is a rich Hemphillian (North American Land Mammal Age) locality in northeastern Tennessee, USA, and has produced tens of thousands of fossils of multiple taxa including hundreds of individual snake skeletal remains. One of only five sites of similar age east of the Mississippi River, the Gray Fossil Site is crucial to our understanding of snake evolution and diversity. Microfauna were collected by screenwashing sediment and picking under a microscope. Specimens were identified using a suite of measurements and characters. Analyzed here are vertebral fossils identified as belonging to various colubrid taxa including Worm Snakes (Carphophis sp.), Ring-Necked Snakes (Diadophis sp.), Hook-Nosed Snakes (Gyalopion sp.), and Hognose Snakes (Heterodon meadi sp. nov.). Carphophis sp. and Gyalopion sp. represent first occurrences in the Mio-Pliocene and dramatically extend their temporal range from the Pleistocene. The four snakes, including one new species, are in accordance with the previously identified taxa by Jasinski and Moscato (2017; Journal of Herpetology 5:245–257), represent a modern assemblage of advanced snakes by the Mio-Pliocene and support a forested environment in northeastern Tennessee.

Amphibian skin secretions are a rich source of antimicrobial peptides that have long interested both the biomedical and herpetological research communities. While anuran skin peptides are well studied, little is known about skin peptides in salamanders, in part because methods for collecting them are poorly developed. In anurans, pharmacological agents are commonly used to stimulate skin peptide responses, thus increasing the amount of peptide collected. It was unclear whether similar methods would work for salamanders. We conducted a series of experiments to test the effects of immersion in pharmaceutical agents (norepinephrine hydrochloride [NE]; acetylcholine chloride [Ach]), handling, and the interaction of both on peptide collection from the skin of Red-Spotted Newts (Notophthalmus viridescens) and Allegheny Mountain Dusky Salamanders (Desmognathus ochrophaeus). Our results suggest that vigorous handling, but not immersion in NE or Ach, is a better method for collecting salamander skin peptides. Despite the widespread use of pharmaceuticals to collect anuran skin peptides, we found little evidence that NE or Ach induces peptide release in salamanders. In fact, we show that inclusion of NE in collection solutions interferes with peptide quantification in protein assays.

Buergeria japonica (Rhacophoridae) thrives in diverse habitats, from montane forests to the mouths of small rivers opening onto sandy beaches. The osmoregulatory system of B. japonica may differ between populations living in these contrasting environments. In this study, we compared the activity of cutaneous Na⁺/K⁺-ATPase in two populations of B. japonica from different habitats (montane vs. coastal). Our results reveal a significant difference between the Na⁺/K⁺-ATPase activity of the two populations of B. japonica, with the coastal population having higher Na⁺/K⁺-ATPase activity. Because the Na⁺/K⁺-ATPase plays a crucial role in osmoregulation in high salinity, these results are consistent with the higher salinity tolerance of the coastal population. It is not known whether the difference in Na⁺/K⁺-ATPase activity between populations is a result of local adaptation or phenotypic plasticity. More detailed work will be needed to disentangle the patterns of differentiation in physiological responses to salt in these amphibians.

We describe a new species of Microtegu lizard (Selvasaura) from the Amazonian slopes of the Andes in Ecuador. Among other characters, the new species differs from the only other known species of Selvasaura, namely, Selvasaura brava from Peru, in having more femoral pores in males and a unilobed hemipenis. We present the first description of the skull of Selvasaura, along with a molecular phylogeny of Cercosaurinae and genetic distances as additional evidence supporting delimitation of the new species.