Hawksbill Turtle ( Eretinochelvs imbricata) 



Status Report of the Hawksbill Turtle (Anne 

 Meylan) 



The hawksbill turtle, Eretmochelvs imbricata . occurs in 

 tropical and subtropical seas of the Atlantic, Pacific and Indian 

 Oceans. It is widely distributed in the Caribbean and western 

 Atlantic, normally ranging from southern Florida, along the 

 central American mainland south to Brazil, and throughout the 

 Bahamas and the Greater and Lesser Antilles. Biological data on 

 the species have been briefly reviewed at this conference by 

 Peter Pritchard, but in this evaluation of the status of the 

 species, certain relevant points are worth repeating. 



Unlike other species of marine turtles, the hawksbill nests 

 diffusely throughout its range, with few known nesting 

 aggregations. This diffuse distribution and the fact that 

 nesting may occur for six or even nine months of the year at some 

 locations make this species one of the most difficult to study. 

 It has been the subject of few intensive studies and 

 consequently, knowledge of key aspects of the reproductive 

 biology, such as the average number of nests per female per 

 season, is poor. With few tagging programs, knowledge of 

 migratory habits and patterns has also remained fragmentary. 



In addition to the species' diffuse nesting distribution, 

 other factors make hawksbill populations difficult to census. 

 Hawksbills nest on widely diverse beach types, including habitats 

 that might be considered marginal for other species such as small 

 pocket-beaches, beaches obstructed by coral reefs, and low-energy 

 beaches inside lagoons. These are areas that tend to be 

 undersurveyed . The ephemeral nature of the hawksbill 's track 

 also contributes to censusing difficulties, and to 

 underestimation of hawksbill nesting abundance. 



Other factors are likely to lead to overestimation. Recent 

 surveys of hawksbill nesting beaches in the Caribbean have shown 

 that a relatively large proportion of crawls does not result in 

 nests. On Mona Island, Puerto Rico, for example, hawksbills make 

 an average of 2 . emergences per successful nest and females have 

 been recorded to make as many as 11 digging attempts on a single 

 emergence (Kontos 1988) . Because the ratio of crawls to nests 

 varies geographically with local conditions, information of this 

 kind on a site-by-site basis is important in order to evaluate 

 accurately aerial survey data. 



Whereas population estimates for all marine turtles are 

 fraught with error, those for hawksbills are perhaps the least 

 accurate for the reasons discussed above. In the evaluation of 

 population status that follows, estimates discussed herein are 

 considered to be only rough indicators of the true size of 



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