Ecological research demonstrates how intraspecific phenotypic variation can have consequences for community dynamics. However, the effects of animal personalities (i.e., intraspecific behavioral variation) on ecological processes remains relatively understudied. Using Red-backed Salamanders (Plethodon cinereus) and the detrital food web as a model system, we conducted a laboratory mesocosm experiment to explore whether or not the personality type of a top-level predator could affect the community structure within a complex, terrestrial food web. We used behavioral assays to investigate the repeatability of salamander behaviors, and classified individuals as either active or inactive. We then subjected laboratory mesocosms to one of four treatments for 3 mo: one active salamander, one inactive salamander, control (no salamander), and a pre-experimental reference. Our results indicate that the effect of P. cinereus on the detrital food web might be behaviorally mediated, with only the most active salamanders affecting community structure. Specifically, mesocosms housing active salamanders contained less diverse invertebrate communities than all other treatments. This difference was primarily driven by springtails, which were more abundant within mesocosms housing active salamanders. We also found that salamander personality was associated with cover board use inside mesocosms, with inactive salamanders exhibiting a more philopatric use of cover objects than active individuals. Leaf-litter degradation did not differ between treatments, indicating that the ecological effects of salamanders were too weak to influence basal resources within the detrital food web. Our study prompts further questions regarding the potential for animal personalities to influence ecological processes within terrestrial communities.

Body surface area and volume are both physiologically important traits in amphibians, as their ratio constrains transport rates for water and respiratory gases across the skin. This is especially true in the lungless salamanders (Urodela: Plethodontidae), whose lungless morphology restricts nearly all gas and water transport to the body surface. Due to methodological difficulties of measuring surface area and volume, estimation techniques are the most convenient way to produce usable phenotype scores. To this end, we used high-resolution computerized tomography (CT) scans of three plethodontid species varying in body size and shape to produce allometric regression models to estimate body surface area (SA), volume, and surface area-to-volume ratio (SA:V). We compared our model estimates to empirical measurements and established estimation methods employed in the Plethodontidae using linear models and Deming regressions. We found our model estimates are both accurate and generalizable across temperate plethodontid species. This method significantly improves SA estimation accuracy when compared to published allometric models. Our models are also significantly more accurate than SA or volume estimates following geometric measurements, although SA:V estimates are comparable between these techniques for most body sizes. We discuss the relative utility of different estimation methods for future research questions.

Túngara Frogs, Engystomops pustulosus, are known to reduce the complexity of their calls in the presence of predators. Although complex calls are more attractive to females, they also attract predators, particularly frog-eating bats, and are rarely emitted by solitary males. Therefore, if Túngara Frogs were to be released from predation pressure, as on the island of Taboga in the Gulf of Panama where frog-eating bats are absent, such constraints on calling should be alleviated. We compared the calling behavior of Túngara Frogs on Taboga with the calling behavior of those on Barro Colorado Island, located in central Panama where frog-eating bats are present, using timed video recordings. Compared with Túngara Frogs on Barro Colorado Island, male Túngara Frogs on Taboga called more, emitted consistently more calls in choruses, and called both day and night. On Taboga, even solitary males routinely embellished their calls with chuck elements. These results are consistent with a hypothesis of predator release positively affecting calling behavior.

In arid regions with summer rainfall, herbivorous reptiles are able to acquire water and fresh food in the presence of high environmental temperatures that can promote ectotherm activity. However, extremely high temperatures and below average rainfall may also limit foraging opportunities due to risks of overheating and predation while gathering scarce food. Karoo Dwarf Tortoises (Chersobius boulengeri) inhabit an arid region in South Africa where most rains fall around austral summer (October–May). We used focal-animal observations and instantaneous recording to assess their behavioral patterns. Despite relatively high rainfall and available plant growth, Karoo Dwarf Tortoises spent approximately 80–90% of their time in retreats. Whereas activity (behavior outside retreats) in the spring was unrelated to time of the day, possibly due to moderate ambient temperatures, activity in the summer was restricted to the afternoon and evening, when tortoises walked and scanned for food and retreats, and fed only 11 min/d on average. In summer, body temperature of tortoises within retreats was positively associated with retreat temperatures, but tortoises appeared to thermoregulate using bodily postures and possibly other means. We suggest that Karoo Dwarf Tortoises mitigate predation risks by maintaining a low level of activity and thermoregulating within retreats. The short feeding time of Karoo Dwarf Tortoises compared to other tortoise taxa may result in slow growth and reproductive rates, which might in turn affect population resilience and conservation needs of this endangered species.

The geographic distribution of a species is limited by many factors, including its ecological and evolutionary history. Species distribution modeling has been used to evaluate the effects of climate and other variables on geographic distribution and to measure the degree of niche similarity among co-occurring species. Our goal in this study was to compare the geographic distributions and ecological niches of four closely related species of lined ground snakes, Lygophis dilepis, L. flavifrenatus, L. meridionalis, and L. paucidens. These species are distributed along the South American Dry Diagonal. We found that the four species of Lygophis overlap somewhat along their distributions with a low degree of niche overlap. Lygophis dilepis shows a disjunct distribution with two isolated populations. The break in the distribution of L. dilepis in Central Brazil is filled by L. meridionalis, which is found mostly in the highlands of the Central Plateau. Because of the disjunct distribution of L. dilepis, we performed species distribution modeling on both populations separately. The environmental niches of the two populations of L. dilepis were indistinguishable according to the niche equivalence tests, but the distribution of one of these populations did not predict the distribution of the second one, and vice versa. Our study shows that niche partitioning may allow for the coexistence of Lygophis species.

Female reptiles may be able to increase the fitness of offspring by selecting nest sites that are less vulnerable to human disturbances and predators, while providing an appropriate thermal and hydric environment for incubation of their eggs. Northern Pine Snakes (Pituophis melanoleucus) in the New Jersey Pinelands are the only snake in North America known to spend days digging their nests, exposing themselves to predators and people. Both nest site and the habitat selected are critical to ensuring reproductive success. Our overall objective was to determine the factors involved in nest-site selection by Northern Pine Snakes to determine trade-offs females face, and to determine whether these characteristics appear to have changed over the last 37 yr in response to human activities and habitat degradation. We compared characteristics of nest sites, random points within clearings, and random points in the surrounding forest for 42 Northern Pine Snake nests in 2020, and secondly, compared specific characteristics with those of 22 nests examined in 1983. The data indicate that (1) nest sites in 2020 were usually in soft sand, rather than in hard packed sand or in “sugar sand”; (2) sand penetration (e.g., sand density) of nests exhibited a narrow range, while random points were in sand ranging from sugar sand to hard packed sand; (3) the ground cover of nest sites was more often moss/lichen compared with other vegetation; and (4) nest sites were in more open habitats than random points within clearings or the surrounding forest. Compared to the 1980s, Northern Pine Snake nests examined in 2020 were in similar habitat conditions (intermediate sand type, open habitats, with surrounding forests), but were more often on paleodunes, deeper in forests, with higher rates of off-road-vehicle (ORV) disturbances. Females spend 2–4 d digging their nests, presumably to ensure appropriate conditions for offspring embryogenesis and to protect eggs and hatchlings. Our results indicate that, while digging, they are vulnerable to thermal stress, predation, poaching, and mortality from ORVs. Thus our results highlight the trade-off between the fitness of the nesting female and the fitness of her offspring.

We describe a large gecko of genus Hemidactylus from the southern face peneplain foothills of the Central Highlands of Sri Lanka. It closely resembles Hemidactylus hunae but is distinguished by adult males reaching 121.2 mm snout–vent length; presence of 11 or 12 supralabials at the midorbit position; dorsal scalation of homogeneous granules intermixed with large, conical, carinate tubercles that form 12–14 irregularly arranged longitudinal rows at midbody; dorsal furrow distinct with a narrow space between medial parasagittal rows; 3 or 4 pairs of postmentals; no spine-like tubercles on nape; ventrals in 36–39 rows at midbody; 21–24 femoral pores on each side separated medially by 5–7 nonpored enlarged scales; scales on posterior thigh granular, not enlarged; lamellae divided, 12 or 13 below the fourth toe; tail segmented with whorls of lateral tubercles, with each whorl consisting of 6 enlarged, conical, carinate tubercles; median row enlarged and broad; single postcloacal tubercle (spur) on each side; and body dorsum with a series of black edged bright saddles from occiput to tail tip. Additionally, we provide a redescription for H. hunae based on its adult female holotype.