Social interactions and associated behaviors are highly important components of fitness and are variable across vertebrates. Historically, such behaviors have been overlooked and understudied in many taxa, including snakes. One type of social behavior well documented in snakes is their reproductive behavior, specifically male–male combat and other agonistic interactions. Although male–male combat and related agonistic interactions are known to occur in many snake species, behaviors are variable and rarely discussed beyond simply recording occurrence. Additionally, the cryptic nature of most snakes makes observing male–male combat and other agonistic interactions in a natural setting immensely difficult. Here, we use both field videography and 8 years of visual encounter surveys to fill in a data gap regarding the agonistic behaviors of Pygmy Rattlesnakes (Sistrurus miliarius) during the reproductive season. For our focal population of Pygmy Rattlesnakes in central Florida, field videography was more effective for observing agonistic interactions and reproductive behaviors than the more frequently employed visual encounter surveys. Using captured video, we provide the first description, quantification, and analyses of male–male combat between free-ranging Pygmy Rattlesnakes, as well as the first description of submissive tail-raising behavior by free-ranging male rattlesnakes. Additionally, we describe other instances of active defeat, passive defeat, and mate-guarding behaviors. Our study reveals that Pygmy Rattlesnakes display a wide range of agonistic and reproductive behaviors, all of which were under-reported or missed entirely during previous research. Our work provides novel insight into intraspecific social interactions of Pygmy Rattlesnakes and highlights the effectiveness of field videography as an emerging tool for ethological research with cryptic animals in their natural habitat.

Aquatic funnel traps and light lures are widely used for surveying amphibians in wetlands, but researchers must select among various trap designs and configurations for any particular study. We examine the performance of glow sticks and four types of aquatic funnel traps, including three commercial minnows and a handcrafted, deep-water trap, on surveying wetland-breeding amphibians, including the Blue-spotted Salamander complex (Ambystoma laterale and Unisexual Ambystoma), Spotted Salamanders (A. maculatum), and Wood Frogs (Lithobates sylvaticus) in central Maine. We performed this study from April–May 2023 and 2024 in 15 freshwater wetlands, which were trapped with the four types of traps crossed with two light treatments (i.e., glow stick present or absent) for a total of eight treatment combinations. We deployed 1–3 replicates of each combination every night for 1–3 nights at each site, yielding 633 total trap nights. We used linear and generalized linear mixed models to compare capture probabilities, counts, and body size (snout-vent-length and mass) of amphibians among trapping methods. Trap designs exhibited taxonomic biases, with the Blue-spotted complex (mostly unisexual females) displaying greater captures in deep-water traps than commercial minnows, Spotted Salamanders displaying equivalent captures in all trap types, and Wood Frogs displaying fewer captures in deep-water traps than commercial minnows. Glow sticks boosted capture probabilities and counts of spotted salamanders, weakly improved capture probabilities for the Blue-spotted complex, and, in contrast to previous studies, had no effect on Wood Frogs. Trapping methods exhibited weak morphological biases for Spotted Salamanders, which were longer and heavier in deep-water traps and shorter and lighter in traps with glow sticks. Captures declined for all species over the season and with successive trap nights, highlighting an important consideration for optimizing landscape-scale studies for cryptic species. Future research examining sex and species-specific activity patterns at different depths and light spectra may address remaining uncertainties of aquatic trapping protocols for different amphibians.

The intertwining of spatial ecology, habitat use and selection, and how these factors relate to key life history events, such as reproduction, is critical for understanding animal ecology. A broad ecological view is particularly relevant in populations that face climatic constraints and threats, such as temperate zone reptiles like Western Rattlesnakes (Crotalus oreganus). From 2017–2019, we used telemetry to study pregnant female C. oreganus in three populations spread over a 174 km stretch of the Okanagan Valley in British Columbia, Canada, with an intent to increase our understanding of female reproductive tactics, life history traits, spatial ecology, and the selection and use of parturition sites (rookeries). Females at the southern site exhibited larger home range sizes, moved farther distances (daily and postpartum), and gave birth earlier than female rattlesnakes at more northern sites. Pregnant females showed site fidelity to rookeries over consecutive reproductive years with temperature attributes, shrub, and rock cover being the variables most strongly associated with the rookery areas that they used. Rather than returning directly to hibernacula following parturition, over 55% of our telemetered females moved away from their hibernacula. Dispersing from hibernacula was presumed to be driven by need for resources. Overall, we identified habitat and temperature variables that are associated with rookeries in this northern region, as well as a high degree of variability in female C. oreganus life histories, movement, and behavior.

Lanthanotus borneensis, Bornean Earless Monitors, are a species of conservation concern, categorized as Endangered in the International Union for Conservation of Nature Red List, and under the list of Totally Protected species in both Kalimantan and Sarawak. We applied radiotelemetry to a study of spatial ecology of nine adults of L. borneensis in Central Sarawak (four males, five females). Minimum convex polygons (100%) were generated for individuals to assess home range sizes. Home range sizes averaged 500.8 ± 300.9 m², and only a slight overlap of space use was observed between sexes. L. borneensis are apparently sedentary for an average of 3 d, with intervening spikes of high movement, highest daily movement being 74 m. Our research demonstrates space use requirements of L. borneensis, which can be applied to conservation management efforts of this and similar tropical herpetofaunal species in Borneo.

The competition-colonization trade-off hypothesis predicts that good colonizers are poor competitors, but good colonizers often coexist in new habitats. Blanchard's Cricket Frogs (Acris blanchardi) are a species of concern and effective colonizers of wetland habitats. Previous studies suggested that Green Frogs (Lithobates clamitans) can outcompete Cricket Frogs, which could contribute to their declines. We examined interactions between these anuran tadpoles across a leaf litter gradient. These species were reared in outdoor mesocosms with leaf litter (0.25 or 1.0 kg) in six community types including ponds that were tadpole-free, or that contained Cricket Frog tadpoles (25 or 50), Green Frog tadpoles (25 or 50), or tadpoles of both species (25 of each). Leaf litter quantity, rather than community composition, had the greatest impact on anuran development and the aquatic community, which may be attributable to increased abundance of periphyton and phytoplankton in high leaf litter treatments over time. High leaf litter treatments produced anurans with larger mass and quicker development on average than low leaf litter treatments. Cricket Frogs showed a trend of lower total survival in high-density communities regardless of competitor identity. Green Frog tadpoles, in contrast, had greater mass in high-density mixed communities than in high-density communities with only Green Frogs, suggesting that they were facilitated by Cricket Frog presence. Our study suggests that colonizing species may be less susceptible to competition with other colonizers and in some cases may enhance the success of each other, boosting the probability of successful colonization events.

Ex situ conservation, translocation, and reintroduction are becoming increasingly important for species restoration. In amphibians, however, effects of captive stress on adults and subsequent effects on their offspring that are later reintroduced into the wild are largely unknown. Using Fowler's toads (Anaxyrus fowleri) as a model species, we investigated effects of increased captive stress on corticosterone (CORT) concentration in adult toads. We then examined CORT levels in their tadpole offspring, which we reared in natural ponds to simulate conditions of a reintroduced population. We found no significant effects of captive stress on adult or offspring CORT levels. However, despite poor model performance due to low sample size, baseline CORT of sires (but not dams) was the best predictor of, and negatively correlated with, baseline CORT and change in CORT in offspring. Our study provides a unique perspective on the potential translation of stress from parent to offspring and points to a need for a closer examination of paternal effects in cases of cross-generational studies in amphibians.

Stable isotope analysis has emerged as a powerful tool for studying food webs and ecological interactions. Our study aimed to compare the trophic ecology, specifically the isotopic niche (δ¹³C and δ¹⁵N), among five species of small lizards inhabiting the Banco Chinchorro Atoll. Results showed no significant differences in δ¹³C and δ¹⁵N values among the sampled species, suggesting that all species utilize similar resources and occupy a similar isotopic niche area. Given the limited food resources in the atoll, spatial niche partitioning, proposed by Pianka (1973), may be present, potentially limiting competition among species. Lizards are known to exhibit a wide range of spatial niche partitioning strategies. Further investigations are warranted to determine whether these lizards engage in interspecific interactions, such as competition or facilitation, which could shape their dietary choices and isotopic niches. Comprehensive diet analysis, habitat characterization, and environmental monitoring are needed to elucidate underlying mechanisms driving convergence of isotopic niches among these lizard species in the Mexican Caribbean atoll.

El análisis de isótopos estables se ha revelado como una poderosa herramienta para estudiar las redes tróficas y las interacciones ecológicas. El objetivo de este estudio era comparar la ecología trófica, concretamente el nicho isotópico (δ¹³C y δ¹⁵N), entre cinco especies de lagartijas que habitan el atolón de Banco Chinchorro. Los resultados no mostraron diferencias significativas en los valores de δ¹³C y δ¹⁵N entre las especies muestreadas, lo que sugiere que todas las especies utilizan recursos similares y ocupan una zona de nicho isotópico similar. Dados los limitados recursos alimenticios del atolón, es posible que se dé la partición espacial de nicho propuesta por Pianka (1973), lo que podría limitar la competencia entre las especies. Se sabe que las lagartijas muestran una amplia gama de estrategias de partición espacial del nicho. Se necesitan más investigaciones para determinar si estas lagartijas participan en interacciones interespecíficas, como la competencia o la facilitación, que podrían dar forma a sus elecciones de dieta y nichos isotópicos. Se necesita un análisis exhaustivo de la dieta, la caracterización del hábitat y el monitoreo ambiental para dilucidar los mecanismos subyacentes que conducen a la convergencia de nichos isotópicos entre estas especies de lagartijas en el atolón del Caribe mexicano.