Dynamic switching in attack and defense behaviors between a predator and maternal guardians of its prey

Background/Question/Methods

The relationship between predator and prey is one that is constantly evolving. Dynamics of this interaction are fundamental to our understanding of behavior in both species. However, majority of studies only focus on examining behavior from the predator’s or prey’s perspective. A particular type of predator-prey interaction lies between an egg-eating predator and the egg-caring parent of their prey. Here, we examine predatory behavior of an oophagus katydid and anti-predator behavior by a frog with egg-stage maternal care concurrently. Specifically, we address the following questions: (1) Do katydids respond to frog egg availability? (2) Is katydid predatory behavior affected by its life history characteristics? (3) Do frogs respond to presence of predatory katydid? (4) Is frog anti-predator behavior correlated with their involvement in parental care? And (5) is parental investment in defense influenced by offspring age? We addressed these questions using both visual encounter surveys in the field and focal observations of predator-prey interactions in the lab. 

Results/Conclusions

We illustrate effects of life-history characteristics of predators on their behavior, and consequently parental behavior of prey. Predatory behavior in katydids increased with age, an ontogenetic behavioral shift that may be related to changes in diet. Anti-predator behavior in frogs was sex-specific. The differential response to risk levels by guardian female frogs only suggests this behavior is driven by their involvement in parental care. Contrary to previous theories, parental investment was positively correlated with predation risks and was not influenced by offspring age. Overall, this study highlights the need to consider factors influencing both species concurrently when examining the complex interaction between predators and parents.