A new species of Oedipina (subgenus Oedopinola) is described from a cloud forest locality in northwestern Honduras. The new species appears most closely related to Oedopinola gephyra, a cloud forest species from north-central Honduras. It differs from O. gephyra in having a larger size, a jet-black coloration, a row of white flecks ventrolaterally on the body in life, and less interdigital webbing on the hind limbs.

Aspidoscelis neotesselata (Squamata: Teiidae), the triploid, parthenogenetic lizard endemic to southeastern Colorado, originated from a hybridization event involving normally parthenogenetic Aspidoscelis tesselata and bisexual Aspidoscelis sexlineata. A previous study of a sympatric assemblage of these taxa in the Higbee vicinity, Otero County, Colorado, found that A. neotesselata resembled A. tesselata in snout–vent length (SVL) and the much smaller A. sexlineata in clutch size, a pronounced departure from the clutch size predicted from the mean SVL of gravid females. The phylogenetic constraint hypothesis, that clutch size in A. neotesselata is influenced disproportionately by the genome acquired from A. sexlineata, was proposed to explain this enigma. Use of new characters in recently acquired samples of A. tesselata Pattern Class C (N = 44), A. neotesselata Pattern Classes A, B, and C (N = 132), and A. sexlineata (N = 31), revealed that clutch size in A. neotesselata is genetically constrained by both progenitors—a nonadditive component from A. tesselata (large egg volume) and an additive component from A. sexlineata (reduced body volume). Although mean oviductal egg volume, mean SVL for hatchlings of the year, and maximum observed body size were similar in A. neotesselata and A. tesselata, representatives of A. neotesselata attained reproductive maturity at smaller body sizes, and their oviductal eggs were proportionately longer and narrower than those of both progenitor species. Gravid individuals of A. neotesselata were intermediate to those of A. tesselata and A. sexlineata in body volume (BV) and SVL, but, as previously reported, the mean clutch sizes of A. neotesselata and A. sexlineata were similar and significantly smaller than that of A. tesselata. Statistically, egg volume was the least variable of the four primary reproductive attributes investigated. This would presumably ensure the production of hatchlings of adaptive size by each species, a factor that likely supersedes clutch size and body volume in maximizing individual fitness. Hybrid-derived polyploidy (i.e., the addition of an A. sexlineata genome to the diploid genome of A. tesselata) in A. neotesselata and the postformational origin of geographic Pattern Classes A, B, and C, have resulted in a constellation of adaptations that extend well beyond reproductive characteristics. These adaptations have permitted each of the three triploid pattern classes to exploit mutually exclusive habitats, some at a distance of 173 linear kilometers west-northwest of the northern range boundary of A. tesselata in southeastern Colorado.

A new species of Plectrohyla is described from the Sierra de Miahuatlán in southern Oaxaca, Mexico. It is known from a single adult female obtained from pine-oak forest at 2550 m. The new species is similar to Plectrohyla cembra in size, habitus, and in having a partially concealed tympanum but differs most notably in aspects of color pattern, hand morphology, head shape, and palatine features.

We explored the association between Van Dyke's Salamander (Plethodon vandykei) and hydrologic condition, geomorphology, and vegetation structure in headwall seeps in the Cascade Range of Washington State. After conducting salamander surveys and measuring habitat characteristics at 40 seep sites from July to August of 2002, we modeled occurrence of P. vandykei at three site scales: between seeps, within seeps, and between microhabitat sites. We ranked a priori models using Bayesian Information Criterion (BIC). Using logistic regression, with presence and absence as the response, we found best approximating models for the occurrence of P. vandykei at the three site scales is predicted by hydrological and geological habitat characteristics. Between seeps, the probability of the occurrence of P. vandykei increased with increasing proportions of seep face having both dry and sheeting hydrology, and increasing proportions of seep face > 5 m high. Within seeps, the probability of the occurrence of P. vandykei was negatively associated with seeps where total overhead cover was > 25%. Between microhabitat sites, the probability of the occurrence of P. vandykei was positively associated with increases in the percent cover of small cobble, small gravel, and bedrock. P. vandykei appears to be associated with habitats that maintain cool thermal and hydric conditions favorable for a species that is sensitive to heat and desiccation due to physiological constraints.

We compared various methods of amphibian marking techniques suggested by a University Institutional Animal Care and Use Committee (IACUC) to assess alternatives to toe-clipping without anesthesia. Marking treatments applied to Dusky (Desmognathus fuscus) and Seal (Desmognathus monticola) Salamanders included visible implanted elastomer (VIE) injections, toe-clipping without anesthesia, toe-clipping with a local anesthetic, toe-clipping with whole body anesthesia, and a control group (handled–unmarked). Randomly selected individuals in each group were euthanized and heads and torsos assayed to assess the effect of the marking techniques on stress hormone responses (adrenaline [epinephrine] and noradrenaline [norepinephrine]) levels. Behavioral responses were also observed in a randomly selected group of individuals from each treatment. We found no significant statistical differences in any of the marking methods on the stress hormone responses or on the behaviors of the salamanders. Our findings suggest that toe-clipping (without anesthesia) and VIE do not differ in their respective effects on stress hormone levels linked to the infliction of pain. We suggest that toe-clipping without anesthesia is a viable and humane field technique for marking desmognathine salamanders and similar organisms.

In lizards identification of food using chemical cues allows active foragers to locate hidden prey and omnivores and herbivores to identify palatable plant food, but ambush foragers identify food visually rather than chemically. Omnivores and herbivores derived from ambushing ancestors discriminate food chemicals from control substances. The only known exception is the omnivorous phrynosomatid lizard Sceloporus poinsettii, which lacks food chemical discrimination and which might have been constrained from evolving it by scarcity of chemoreceptors. We studied food chemical discrimination by the phrynosomatid Uma exsul, an omnivore whose diet is 25% plant by volume. In 60 s trials in which chemical cues from mealworms, romaine lettuce, cologne, and water were presented on cotton swabs, lizards responded more strongly to plant and animal chemicals than control stimuli. Food chemical discrimination by Uma exsul strengthens evidence that plant chemical discrimination evolves in tandem with plant diet and prey chemical discrimination also appears in omnivores or herbivores derived from ambush foragers. Confirmation of food chemical discrimination in U. exsul vitiates the evolutionary constraint hypothesis for S. poinsettii. That lizards tongue-flicked and bit infrequently, yet discriminated, is unusual, suggesting that lingually mediated plant chemical discrimination may have evolved recently, few tongue-flicks are needed to evaluate nutritive properties of plant foods, or plant chemical discrimination is an adaptively unimportant epiphenomenon of plant consumption. Because they do not search actively for prey or tongue-flick before attacking, phrynosomatids presumably evolve prey chemical discrimination by genetic correlation with plant chemical discrimination.

Identifying microhabitat preferences is important in understanding distributions of organisms and crucial to focusing conservation efforts. The Five-Lined Skink (Eumeces fasciatus) is a rock-dwelling diurnal lizard that, in Canada, is considered a species of “special concern” under the recently passed Species at Risk Act (SARA). In this study, we examined the early-season diurnal retreat site selection preferences of the Five-Lined Skink at the northern limit of its range. To determine preferences we compared dimensions, thermal properties, and other associated microhabitat characteristics of rocks under which skinks were found to randomly selected rocks in two populations. A matched-pairs logistic regression revealed that individuals of E. fasciatus prefer longer than average cover rocks located in areas with few trees. We also found that, compared to other available cover element-substrate combinations, rocks lying on a bedrock substrate afford the best opportunities for skinks to achieve preferred body temperatures. These retreat site preferences are likely driven both by the necessities of thermoregulation and protection from predators.

The Late Eocene (Chadronian NALMA) Hardie Mine local fauna of the Clinchfield Formation in Wilkinson County, Georgia, preserves the most diverse turtle fauna in the Eocene of southeastern North America. This fauna includes at least five taxa including a dermochelyid, a cheloniid, a trionychid, a testudinoid, and an unidentified cryptodire. Chelonioids and trionychids are the most common turtles in this near-shore marine deposit. The aquatic testudinoids from the Hardie Mine site represent the oldest records from southeastern North America, a region that exhibits a high diversity of extant aquatic testudinoids.

We studied sexual dimorphism and female reproduction in Many-Lined Sun Skinks (Mabuya multifasciata) from a population in Hainan (southern China). The smallest reproductive female was 90 mm snout–vent length (SVL). The largest male was 117 mm SVL and the largest female was 116 mm SVL. To measure the potential influence of gestation temperature on female reproduction, pregnant females were maintained under five thermal conditions until they gave birth. Parturition began in early May, and females produced up to two litters per breeding season. Litter size, litter mass, and offspring size (mass) were all positively correlated with female SVL. Litter size ranged from 2–7, and it was independent of relative fecundity (litter size relative female SVL). We did not detect a trade-off between body size and offspring number. Gestation temperature affected parturition date but not litter size, litter mass, neonate mass, or relative litter mass. Females at higher (average) gestation temperatures gave birth to young earlier than did those at lower temperatures. The detrimental effects of extreme ambient temperatures on offspring body size could be buffered through maternal thermoregulation.

We reared hatchling Midland Painted Turtles (Chrysemys picta marginata) and Red-Eared Slider Turtles (Trachemys scripta elegans) on either black or white substrates for 120 days. Spectral reflectance of the third vertebral scute, dorsal skin of the head, and lateral margin of the abdominal scute was measured at 30-day intervals between days 0 and 120. Mean carapace intensity significantly decreased over time (turtle shells darkened) in T. scripta but did not change in C. picta in individuals reared on a black substrate. Mean carapace intensity increased significantly (turtle shells lightened) through time in C. picta reared on white substrates. Mean carapace intensity of T. scripta reared on a white substrate did not change through time. Mean intensity of dorsal head skin decreased significantly through time in T. scripta reared on black substrates. In C. picta and T. scripta reared on white substrates, mean intensity of dorsal head region skin increased significantly between days 0 and 120. Regardless of substrate color, the lateral margin of the plastron significantly darkened through time in C. picta and T. scripta. In C. picta and T. scripta reared on white substrates, reflectance spectra lines of the carapace and dorsal head skin tended to have high elevations (peaks in the 520–640 nm region). The high reflectance was indicative of a lighter green coloration relative to turtles reared on black substrates.

Terrapene carolina and Terrapene ornata are sympatric in Missouri, but they tend to occupy different habitats. There is also disparity in their diets, with T. carolina tending to be more herbivorous than T. ornata. Differences in diet and habitat may require different digestive physiologies between species. We investigated the ability of these species to digest three different pure diets of fruit (blackberry, mayapple, and strawberry). Diet type had a significant effect on digestive efficiency and gut transit rate. We found T. carolina had significantly longer gut transit times than did T. ornata when fed strawberry diets but not when fed blackberry and mayapple diets. Terrapene ornata had significantly higher digestive efficiency than did T. carolina for mayapple diets but not for strawberry and blackberries diets. This study suggests that diet-dependent differences in digestive ability exist between these turtle species.

We describe a new species of Colostethus from the Península de Paria in northeastern Venezuela. It inhabits the cloud forest of Cerro El Humo at an altitude of around 1000 m. By its morphology, the new species most closely resembles Colostethus bromelicola from the central Venezuelan Coastal Range. It can be confidently distinguished from other Colostethus by a suite of characters, including its dorsal pattern, absence of fringes on fingers, absence of a lingual process, and absence of yellow or orange chest coloration. This description increases to 33 the number of Colostethus species known from Venezuela.

An incomplete left hypoplastron of a trionychid turtle from the late Miocene-Early Pliocene Cubagua Formation of Margarita Island, Venezuela, represents the youngest occurrence of trionychids in South America. Large size and depositional environment of the Margarita Island specimen indicate marginal marine habits. The Neogene Venezuelan record is more extensive than previously considered and may represent an interval of successful colonization of the northern margin of South America by trionychids, as opposed to previous hypotheses of failed waif immigration.

Appropriate and relevant measures of body size are essential to understand scaling relationships or to compare morphometric data from specimens or taxa of different sizes. Traditionally, body mass and snout–vent length have been used as measures of body size in lizards. Here, we report on the relevance of an alternative measure of size, skeletal mass, which is highly correlated with traditional body size measures and may have more practical value when using skeletal measurements based on museum collections.

A study was undertaken to find the role of residual yolk in maintenance and growth in newborn hatchlings of the lizard Calotes versicolor. Hatchlings (N = 90) of C. versicolor were obtained by incubating eggs (from six lizards) on moist sand at ambient temperature in the laboratory. Equal number of hatchlings from each clutch was assigned to each of the three groups. One group of hatchlings was fed daily for 10 days, whereas another group was not fed for the same period. Hatchlings that were fed grew significantly larger, both in snout–vent length (SVL) and body mass compared to the unfed individuals. Unfed hatchlings lost body mass although their SVL increased over the course of experiment. Residual yolk mass declined significantly in both fed and unfed hatchlings compared to the initial controls. Interestingly, fed hatchlings possessed less residual yolk than the unfed counterparts at the end of the experiment. Faster use of residual yolk in the fed hatchlings may be associated with higher metabolic rate/SDA after feeding. It is suggested that, in C. versicolor, residual yolk promotes growth of hatchlings, and it is also used as an energy source for sustenance under situations of scarcity of food or starvation.

Anuran amphibians are important consumers of arthropods in tropical ecosystems. Previous research has indicated that very small, terrestrial frogs, especially juveniles, largely consume small leaf litter arthropods. To date, few studies have examined diet in African anurans, and no studies exist of ontogenetic change in prey composition for any African frog. We investigated the change in diet that accompanies body size increase in the arthroleptid frog Schoutedenella xenodactyloides (Anura: Ranoidea) from a population located on the Mulanje Massif in Malawi, central Africa. Schoutedenella xenodactyloides is a miniature (< 22 mm snout–urostyle length; SUL), direct-developing frog that is often very abundant and is likely an important consumer of small leaf litter arthropods. Based on examination of stomach and intestinal contents from specimens that span the known range of posthatching body sizes, we document the taxonomic diversity of prey consumed by S. xenodactyloides. We present evidence that S. xenodactyloides exhibits a size-related ontogenetic change in the type and relative proportions of prey taxa. Small frogs (≤ 13 mm SUL) consume large numbers of collembolans and mites. As frogs attain larger body sizes; ants constitute a larger percentage of the total number of prey consumed; and collembolan and mite consumption falls below 10% of the total prey items. The prey consumed by S. xenodactyloides include at least 10 orders of arthropods and an unidentified mollusk. This is a greater diversity of prey items than previously found in Schoutedenella as well as most other arthroleptid species.

Paleontological and geological evidence suggest that the distinctive endemic skink Eumeces longirostris could potentially be as old as continuously emergent land on the Bermuda seamount (approximately > 1–2 million yr). The species has experienced sustained evolutionary stasis for at least the past 400,000 yr, during which time there has been no perceptible change in skeletal morphology. The tortoise Hesperotestudo bermudae is known from a single fossil from interglacial period marine isotope stage (MIS) 9—approximately 300,000 yr ago. A viable population of tortoise on Bermuda could be reconciled with the geological record and the lack of any other fossils of the species to date if tortoises colonized the island at or after the end of the maximal sea-level rise of interglacial MIS 11, evolved during the single glacial episode of MIS 10, and become extinct as a result of the interglacial sea-level rise of MIS 9, a period of about 100,000 yr. Such rapid evolution and extinction has a close parallel in the giant tortoises of Aldabra Island in the Indian Ocean.

We investigated whether incubation treatment or size influence sprint speed of tuatara (Sphenodon punctatus) as artificial incubation is often used to produce founders for new populations of this endangered reptile. Sprint speed was affected by age, clutch and incubation regime (natural vs. artificial incubation). Older juveniles ran faster than younger juveniles. Maternal influence, represented by clutch, accounted for 18% of the variance in sprint speeds at one month of age. Naturally incubated juveniles were the smallest animals of any incubation regime, but at 10 months of age these juveniles were the fastest runners. Naturally incubated juvenile tuatara were more aggressive and faster for their size than artificially incubated juveniles, suggesting they may have higher fitness when released.

Rana catesbeiana (American Bullfrog) is exotic in western North America and is sympatric with two native species, Rana luteiventris (Columbia Spotted Frog) and Pseudacris regilla (Pacific Treefrog). In a laboratory experiment, we assessed the growth of tadpoles of R. luteiventris and P. regilla in the presence and absence of tadpoles of R. catesbeiana. We found that in the presence of tadpoles of R. catesbeiana, P. regilla exhibited rapid growth in early larval stages compared to R. luteiventris. A second experiment indicated that, when reared with R. catesbeiana, P. regilla increased activity levels; this behavioral disparity may partly explain the observed difference in growth responses of the two frog species to R. catesbeiana competition. Our results suggest that tadpoles of P. regilla display greater growth and behavioral plasticity than do R. luteiventris, when subject to competition with R. catesbeiana. Rana luteiventris may be more susceptible than P. regilla to R. catesbeiana-mediated numerical decline, if exploitative or interference competition between tadpoles is a population-limiting factor in western breeding ponds.

Bothrops mattogrossensis occurs in open wet habitats in the Pantanal of western Brazil. As part of a series of studies focusing on how ecological characters evolved in the genus Bothrops, we gathered information on diet, reproduction, and morphology for B. mattogrossensis using museum specimens. Bothrops mattogrossensis has a generalized diet (anurans, small mammals, lizards, snakes, and centipedes), a plesiomorphic character in the genus Bothrops. We found no evidence of an ontogenetic shift in diet from ectothermic to endothermic prey, as observed in other species of Bothrops. Feeding frequency is high (68.8%) compared to other Bothrops spp. Reproduction is seasonal, with a vitellogenic period concentrated at the end of the dry season. Fecundity is relatively high, with clutch size varying from 18–37. Females are significantly larger in snout–vent length and have significantly shorter tails and relatively larger heads than males. Although mostly terrestrial, B. mattogrossensis is relatively slender and has a longer tail than other terrestrial Bothrops, possibly an adaptation for climbing into vegetation during seasonal floods.