Sum of fears among intraguild predators drives the survival of green sea turtle (Chelonia mydas) eggs
Journal
Proceedings of the Royal Society B: Biological Sciences
Journal Volume
288
Journal Issue
1944
ISSN
0962-8452
Date Issued
2021-02-10
Author(s)
Abstract
Ecologists have long theorized that apex predators stabilize trophic systems by exerting a net protective effect on the basal resource of a food web. Although experimental and observational studies have borne this out, it is not always clear what behavioural mechanisms among the trophically connected species are responsible for this stability. Fear of intraguild predation is commonly identified as one such mechanism in models and mesocosm studies, but empirical evidence in natural systems remains limited, as the complexity of many trophic systems renders detailed behavioural studies of species interactions challenging. Here, we combine long-term field observations of a trophic system in nature with experimental behavioural studies of how all the species in this system interact, in both pairs and groups. The results demonstrate how an abundant, sessile and palatable prey item (sea turtle eggs, Chelonia mydas) survives when faced by three potential predators that all readily eat eggs: an apex predator (the stink ratsnake, Elaphe carinata) and two mesopredators (the brown rat, Rattus norvegicus, and kukri snake, Oligodon formosanus). Our results detail how fear of intraguild predation, conspecific cannibalism, habitat structure and territorial behaviour among these species interact in a complex fashion that results in high egg survival. © 2021 The Author(s).
Subjects
conspecific cannibalism
Elaphe carinata
intraguild predation
Oligodon formosanus
resource partitioning
trophic cascade
Publisher
Royal Society Publishing
Description
Article number 20202631
Type
journal article