Development and survival of reptilian embryos are affected by the temperature and moisture within the nest. Moreover, thermal and hydric conditions during incubation also affect phenotypes of hatchlings. Thus, females should select nest sites that enhance hatching success and produce hatchlings with phenotypes fit for the local environment. The objective of this study was to determine the substrate temperature and moisture conditions selected by eastern fence lizards (Sceloporus undulatus) for nesting. In the laboratory, gravid females were housed in a large enclosure that provided suitable nesting substrate. Gradients of temperature and moisture within the substrate were established to provide a wide range of conditions from which females could choose. Fifteen (65%) females selected nest conditions within the moisture and temperature range that results in successful embryonic development. Two females (9%) nested in extremely dry conditions, and six females (26%) oviposited on the substrate surface. Females that nested in the field selected nest sites with similar conditions as females that nested in the laboratory. In general, we provide support for the idea that females choose nest sites with thermal and hydric conditions that are associated with positive hatching success.

We examined the reproductive frequency in wild-caught and captive females of Tiliqua nigrolutea over five consecutive reproductive seasons. Reproductive frequency (0.38 ± SE 0.035) was clearly different from an annual pattern (1.0) in which all females reproduce every year. Individual females did not reproduce every year, but “skipped” seasons were staggered such that a proportion of the population produced a clutch each season. We attribute skipped reproductive opportunities to a combination of a long gestation, high relative clutch mass (0.43 ± SE 0.034), parturition late in the active season, a cessation of feeding in the latter stages of gestation, and low autumn temperatures that limited post-partum feeding opportunities.

We conducted two laboratory experiments with juveniles of Ambystoma opacum and A. maculatum to test for intra- and interspecific competition for burrows. Experiment 1 examined how the behavior of an intruder (i.e., an individual that enters an occupied burrow) was influenced by the presence of a resident salamander that had been placed in the test chamber 5 d earlier. In Experiment 2, we investigated patterns of cohabitation when salamanders were introduced singly, as conspecific pairs, or as heterospecific pairs during a 7-d test period. The results of these experiments indicate that (1) when maintained alone, juvenile A. opacum were observed more frequently outside of the burrow than were juvenile A. maculatum; (2) A. maculatum were more likely to enter unoccupied burrows compared to burrows that were occupied by conspecific or heterospecific salamanders; (3) A. maculatum intruders were bitten more frequently by resident A. opacum than by resident A. maculatum; (4) when two individual salamanders shared a burrow, A. maculatum were more likely to leave a cohabited burrow whereas use of shared burrows by A. opacum was not influenced by the presence of another salamander in the burrow. These experiments demonstrate that juvenile A. opacum may defend burrow space by excluding heterospecific salamanders. However, our results also indicate that species-specific behavioral differences may influence patterns of burrow use, which may reduce the importance of agonistic interactions under natural conditions.

Although it is widely known that most species of snakes readily accept carrion in captivity, the notion of scavenging by wild snakes historically has been rejected or ignored. Herein, we review the literature describing instances of scavenging by snakes and consider the implications of carrion use on their ecology. Thirty-nine published accounts yielded 50 observations of scavenging by snakes (43 from field observations and seven from laboratory studies). Thirty-five species from five families were represented, but pitvipers and piscivorous snakes were represented more frequently than other groups. Scavenged material varied widely and included rodents, birds, fish, frogs, and snakes. Olfaction appears to be the overriding sensory modality used for carrion detection. Some species may use scavenging as a deliberate feeding strategy that supplements their regular modes of prey acquisition. Additional knowledge of the scavenging behavior of snakes should provide new insights into the fundamentals of the ecology of snakes.

Eastern brownsnakes (Pseudonaja textilis) from south-eastern Australia are alert, well camouflaged, secretive, fast moving, and dangerously venomous, and they spend much of the time hidden in burrows. Thus, direct observation of this species is difficult. However, distinctive patterns in environmental thermal heterogeneity, coupled with knowledge of the thermal preferenda of the snakes, enabled us to infer their location and activity based on remotely monitored body temperatures (obtained from surgically implanted radio transmitters). We used data on 40 radio-tracked snakes to evaluate patterns of thermoregulation, activity, and habitat use.

Captive snakes actively selected body temperatures around 31 C, and free-ranging snakes displayed similar body temperature levels while active. From data on temperatures of the soil, operative models, and shaded air, we could identify activity schedules of the snakes (especially, times of emergence from and retreat into burrows). Snake activity was bimodal over the year, with the highest incidence of above-ground activity in late spring and late summer. Thermal profiles suggest that inactive snakes in burrows spent most of their time at approximately 20 cm depth, but they moved to shallower depths at some times (e.g., during summer, when they sometimes spent entire nights above ground) and deeper at other times (e.g., ≥40 cm in winter). Reproductive females remained with their eggs after oviposition in mid-summer, about 30 cm under the soil surface. Burrow temperatures were frequently high, so that the snakes did not need to emerge in order to elevate body temperature. Overall, the telemetered snakes spent an average of 56% of active-season days, 64% of all days, and 93% of all hours below ground. Hence, this species largely depends on in-ground temperature for thermal energy exchange.

We describe a new species of Hylodes from Parque Estadual do Ibitipoca, Conceição do Ibitipoca, Municipality of Lima Duarte, State of Minas Gerais, southeastern Brazil. The new species is a member of the Hylodes lateristrigatus group, and it is characterized by small size, snout rounded in dorsal view and protruding in lateral view, presence of vocal slits and sacs, upper surface of finger discs without well developed scutes, dorsum light brown to gray with dark blotches, and details of the advertisement call. Descriptions of the tadpole, vocalizations, and information on natural history are provided. The tadpole has a ventral depression anterior to the coiled intestine, as in other species of the genus. Hylodes meridionalis (Mertens), previously considered a member of the H. nasus species group, is transferred to the H. lateristrigatus species group.

We describe a new species of Desmognathus from Union County, Georgia. It closely resembles D. quadramaculatus, but the two are distinguishable by adult size, body proportions, color pattern, and fixed differences at four allozyme loci. The new, smaller species is currently known from two tributaries of the Nottely River and is sympatric with D. quadramaculatus at both sites. The new form is semi-aquatic and utilizes habitats that are similar to those of D. quadramaculatus. Metamorphosis occurs at a smaller size than in D. quadramaculatus, apparently as a result of a shorter larval period. Selection on life history features may have had a role in the origin and divergence of these forms.

We describe a new species of wolf snake of the genus Lycodon from the Cardamom Mountains of southwestern Cambodia. The new species differs from other species of Lycodon in Southeast Asia in the following combination of characteristics: dorsal scales feebly keeled, in 17 rows at midbody; 12 well defined, broad white bands across black body and six across the tail; presence of both a single preocular and a loreal, causing absence of prefrontal-eye contact; three postoculars, two anterior temporals. Visually, the new species is most similar to Lycodon subcinctus, and specimens labeled as L. subcinctus from eastern Thailand and elsewhere in Cambodia should be checked against the diagnosis of the new species.