Hawksbill nest site selection affects hatchling survival at a rookery in Antigua, West Indies

Abstract

Nesting populations of Critically Endangered hawksbill sea turtles remain depleted across much of their range in the Caribbean. Some islands, however, including Jumby Bay (Pasture Bay) in Antigua, have shown a steady increase in the number of nesting females. Furthermore, in recent years nesting has occurred in particularly high densities within the remnant maritime forest on the northwestern side of the bay, concentrating the entry of emerging hatchlings into the sea along a small (~160 m long) length of shoreline. Previous studies have shown that when many hatchlings enter the sea from a restricted location, aquatic predators may exploit that site. We followed 49 hatchlings by kayak at night as they swam offshore, and we determined that predation rates were significantly higher on the western than on the eastern side of the bay. At both locations, the turtles showed no obvious differences in offshore orientation that might have increased their vulnerability to predators. We hypothesize that the greater predation rate was most likely caused by the presence of more predators. To reduce those predation pressures, we recommend a 2-pronged strategy: (1) 'risk-spreading' (releasing hatchlings at other locations adjacent to, and within, the bay), and (2) habitat restoration to expand the area of attractive nesting habitat.