Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon

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  Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon Abstract Snakes exhibit extreme cranial kinesis that facilitates ingestion of prey with large cross-sectional area, but this ability is widely predicted to reduce bite performance due to decreased structural rigidity. Consequently, most large-bodied snakes rely on envenomation or constriction to subdue prey prior to ingestion. Species within the genus Drymarchon represent a notable exception: these large, non-venomous, non-constricting snakes routinely consume a wide range of prey, including large and potentially dangerous vertebrates, using only simple seizing and pinioning behaviors. Here, we quantify bite performance in three species of Drymarchon ( D. corais, D. couperi, and D. melanurus ), examine morphological predictors of biting performance, compare biting pressure to constriction pressure in similarly sized snakes, and synthesize dietary records across the genus. Our results sh...

Microclimate of cemetery habitats and nest site selection of Eresus kollari (Araneae: Eresidae) in South Korea

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Microclimate of cemetery habitats and nest site selection of Eresus kollari (Araneae: Eresidae) in South Korea

Abstract

Nest site selection and construction are important life history events for many animals. These decisions are largely governed by abiotic factors such as temperature, humidity, and solar radiation. Eresus kollari—a burrowing spider that excavates its own nest and rears its offspring within—likewise faces important decisions when choosing where to build. In South Korea, the species often occupies sun-exposed, dome-shaped burial mounds. To understand the behavioral decision-making that leads the species to occupy mound habitats, we conducted field surveys and laboratory experiments. Field surveys showed that 75.6% of all E. kollari nests were found on mound surfaces, with the highest density near the mound center (3.98 nests/m2). Across the hemispherical mound, nests were concentrated on the eastern, central, and western sectors and displayed a slight overall bias toward the south. Mean soil temperature was ~19°C and did not differ between the mound and adjacent ground. In contrast, the mound surface was markedly drier (soil moisture = 4.7%) than the surrounding soil (7.5%). These spiders formed highly localized clusters within their habitats; this clustering pattern resembled a parent–offspring aggregation and also suggested that individuals exhibit preferences for specific environmental conditions. Laboratory selection tests corroborated the field patterns: Spiders preferentially moved away from moist substrates and displayed a strong attraction to illuminated directions. Collectively, these results suggest that E. kollari prefers sunny, dry mound surfaces as nesting sites and settles there to construct nests.

Choi, J. H., Oh, D., Kim, N. H., Lee, J. K., & Kim, K. W. (2026). Microclimate of cemetery habitats and nest site selection of Eresus kollari (Araneae: Eresidae) in South Korea. Ecosphere, 17(7), e70708. https://doi.org/10.1002/ecs2.70708