Sum of fears among intraguild predators drives the survival of green sea turtle (Chelonia mydas) eggs

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.

Sequencing and analysis of mitochondrial genome of Elaphe carinata (Reptilia, Squamata, Colubridae)

The complete mitochondrial genome of Elaphe carinata was sequenced and analysed using muscle tissue for the first time. The genome is 17 154 bp in length. The complete mitochondrial genome contains 22 tRNA genes, 13 protein-coding genes (PCGs), two rRNA genes, two control regions (CRI and CRII) and one putative origin of L-strand replication. The gene order and nucleotide composition of E. carinata are very similar with E. davidi, E. schrenckii, E. anomala and E. bimaculata. A phylogenetic tree of mitochondrial genomes analyses of 16 species snakes of Colubridae was made based on the Neighbour-Joining (NJ) method, E. carinata has the most closely relationship with E. davidi, while E. poryphyracea and Euprepiophis perlacea are special species.