Dog scavenging sea-turtle nests

Ruiz‐Izaguirre, E., Woersem, A., Eilers, K., Wieren, S. E., Bosch, G., Zijpp, A. J., & Boer, I. J. M. (2014). Roaming characteristics and feeding practices of village dogs scavenging sea‐turtle nests. Animal Conservation.

Village dogs are reported to prey on sea-turtle nests at various beaches worldwide. Sea-turtle species present in Mexico include six species, which are listed under the International Union for Conservation of Nature Red List. It is however not clear why dogs scavenge and how they enter nesting areas; this hinders effective management of dogs at sea-turtle nesting beaches. Hunger, for example, could be a driving factor for village dogs to scavenge sea-turtle nests. The aim of this study was to gain insight into roaming characteristics and feeding practices of dogs scavenging sea-turtle nests. Movements of 19 village dogs (9 nest scavengers and 10 non-nest scavengers) at Colola village and beach (an important nesting ground for the eastern Pacific green turtle: Chelonia mydas) were monitored through radio-tracking and direct observations. A prerequisite for nest scavenging is traveling to the beach. We computed ‘distance from home to beach’ and ‘the activity range’ of nest scavengers and non-nest scavengers. Furthermore, the dogs' owners were interviewed regarding feeding practices. Nest scavengers had a lower metabolic energy intake of their daily food corn tortillas (296 kJ kg⁻¹ BW^0.75) than non-nest scavengers (464 kJ kg⁻¹ BW^0.75) (two-sample t-test=2.67, P=0.017). Moreover, 39% of owners reported that they provided turtle eggs or egg shells to their dogs at least once. The activity range of nest scavengers was significantly larger than that of non-nest scavengers (F=11.64, P=0.007). Dogs were generally found at the beach at night (42%) and dawn (34%). Our findings have implications for the management of dogs at sea-turtle nesting beaches. We recommend that dogs' movements should be restricted between night (09:00 pm) and dawn (06:00 am) and that sufficient and adequate feeding of dogs should be promoted among dog owners.