Direitos de Autor (c) 2026 Scientia
Este trabalho encontra-se publicado com a Licença Internacional Creative Commons Atribuição-NãoComercial-CompartilhaIgual 4.0.
A population of Uca heteropleura was studied to examine variation in male antipredator and reproductive behaviors across contrasting lunar phases at El Agallito Beach, Panama (April–July 2025). Crab responses to simulated avian predator fly-bys were quantified using a bird model passed over 5 m² quadrats. Habituation was assessed with repeated exposures (three passes), while single?pass trials evaluated baseline escape responses. Focal individuals were measured (carapace width?length and major chela height?length), and waving frequency and reemergence time were recorded as proxies of reproductive effort and risk-taking, respectively. A total of 616 individuals were recorded with a mean carapace width of 15.9 ± 4.1 mm. Repeated predator exposure significantly reduced escape responses, indicating rapid habituation. In single?pass trials, surface activity and waving frequency were significantly higher during full and new moons compared to quarter moons. Waving frequency showed a weak but significant negative relationship with body size. Escape probability declined with increasing carapace width, with larger individuals less likely to flee and more likely to remain on the surface. Similarly, non-responsive individuals were significantly larger than those that escaped. Reemergence time was shorter during full and new moons, suggesting higher risk tolerance under peak reproductive conditions. These results indicate that antipredator behavior, signaling effort, and risk-taking are modulated by both body size and lunar phase. This coupling of individual state and environmental context highlights the dynamic nature of risk?taking behavior, where crabs continuously adjust their responses to balance predation risk against reproductive and foraging benefits.
Este obra está bajo una licencia de Creative Commons Reconocimiento-NoComercial-CompartirIgual 4.0 Internacional.
