Abstract
The crab-eating fox (Cerdocyon thous) is a key predator of marine turtle nests along Brazil’s northeast coast. To protect turtle nests from natural predators, particularly at the significant nesting site of Barreira do Inferno beach, a comprehensive monitoring program for hawksbill turtle (Eretmochelys imbricata) nests was implemented. Five nest protection strategies were evaluated: the standard TAMAR numbered stake control, pepper powder application, mesh covering, flag markers, and no-intervention. During the 2018/2019 season, 64 nests were monitored, resulting in the observation of 478 fox interactions, categorized into nest visits, nonpredatory excavation, and egg or hatchling predation. Foxes primarily visited newly constructed nests, with decreased visitation as incubation progressed. Predation and excavation occurred mainly during initial and final incubation stages. Our analysis indicates that foxes exhibit exploratory behavior, possibly mapping nests to optimize foraging. The predation rate on the control or the standard TAMAR treatments was around 50%, while for mesh treatment the predation was 17% and flag treatment 13%. Moreover, this study enhances understanding of crab-eating fox predation behavior and informs conservation strategies for marine turtle nests in canid-threatened areas.