Nest site location and nest success in the hawksbill turtle Eretmochelys imbricata in Barbados, West Indies

Abstract

Hawksbills nested more frequently on W coast than S and E coast beaches, suggesting that they prefer beaches with lower wave energy and steeper becah slopes. Sheltered beaches may be preferred because of the mechanical difficulties and energetic costs of moving onto and off high energy beaches. Hawksbills nested at specific elevations above mean sea level, controlled by altering the distance travelled inland on beaches of different slopes. Steeper beaches may therefore be preferred because gravid females and hatchlings may have lower travel costs and lower predation risk. Nest success (number of hatchlings emerging from a nest) was highest from nests closest to mean elevation and declined at higher and lower elevations. This was because emergence success (% eggs laid that emerge as hatchlings) was highest near mean elevation. Hawksbills preferred to nest amongst vegetation. Vegetated nest sites were less compacted than non-vegetated, and had higher escape success. Hatchling sex ratios were biased towards males on cooler south coast beaches and towards females on warmer west coast beaches. -from Authors