Meeting Abstract
Agalychnis callidryas lay eggs over Neotropical ponds and their tadpoles fall into the water upon hatching. Arboreal snakes consume many eggs, but some embryos escape by hatching rapidly during attacks. Snake-induced hatching begins at age 4 days, then escape success improves and becomes more consistent as embryos develop. To elucidate how and why escape success changes, and the role of embryo decisions and hatching performance, we recorded video of snake attacks on embryos of different ages. We caught two common species of nocturnal egg-eating-snakes (Leptodeira septentrionalis and Imantodes inornatus) from a pond in Panama, kept them in terraria under natural temperature, humidity, and photoperiods, and offered them egg clutches of different developmental stages. We used 4K infrared cameras to record macro-video, enabling detailed analysis of individual embryo behaviors. Escape success varied widely, from 0–100% across embryonic ages 3–6 days. Initial analysis suggests that, once embryos can sense vibrations, changes in hatching decisions may affect escape success more than do changes in hatching performance. Development appears to increase the likelihood that embryos will hatch preemptively, in response to indirect vibrations from attacks on clutch-mates, rather than waiting for direct snake contact with their own egg. Such preemptive hatching appears to increase escape rates, although some directly attacked embryos do escape. Further analysis of the videos will examine relationships between hatching decisions, hatching performance, and embryo fates in snake attacks across development through the plastic hatching period. This will contribute to our understanding of the development of embryo behavior and its effect on survival in predator-prey interactions.
