FACTORS INFLUENCING EGG PREDATION OF TWO SYMPATRIC CROCODILIANS IN MEXICO

The rates of eggs predation in crocodilians can be influenced by the abundance of predators, their activity time, the crocodilian size, and parental care. We evaluated the relationship between crocodilian eggs predation and characteristics of the predatory species (egg search intensity and activity hours), of the nesting females (nest defense), and of the nesting site (habitat characteristics and climatic variables). We evaluated nests with camera traps during the 2014 nesting seasons of Spectacled Caimans (Caiman crocodilus) and American Crocodiles (Crocodylus acutus) in the Biosphere Reserve La Encrucijada, Mexico. We identified a relationship between the defense of the nest and the search for eggs by predators. The number of photographic records of females on the nest increased with the number of photographic records of the egg predators. We observed overlap of activity hours between crocodilian females and egg predators. Females were recorded on the nest only when their predator species was present. In addition, some climatic variables (air temperature and rainfall) and nests characteristics (depth to the first egg and distance to the closest tree) were positively associated with the success of egg predation, depending on the predator species.