Description: The Hawksbill (Eretmochelys imbricata)
is a small to medium-sized sea turtle. As an adult, females
may reach lengths of 30 - 35 in (76-89 cm) and weights of 95-165lbs
(43-75 kg), with a record length of 36+ in (90+ cm) and weight
of 180 lbs (127 kg). They have typical hard shells with unique
features such as large thick, overlapping (imbricate) scutes,
deeply serrated carapacial margins, a beak-like mouth, and are
generally brown in coloration. Older adults may lack overlapping
scutes. The carapace is distinguished by 4 pairs of costal
scutes with the first not touching the nuchal. Two pairs of prefrontal
head plates lie between the eyes. The plastron is normally
a cream to amber color which extends to the ventral surface of
the head and limbs. They have two claws per flipper. Juvenile
hawksbills are black to dark brown in color above and below, except
for raised ridges, edges of the shell and areas around the neck
and flippers, which are generally light brown in color. Juveniles
have one middorsal and two plastral keels and are 1.3-2 in (3-5
cm) long at hatching. This species is sexually dimorphic. Males
are generally smaller in size, more colorful and have a different
shell shape than females.
Habitat: Hawksbill turtles are found in warm oceans world-wide.
They can be found along Atlantic seaboard of the Southeast during
the summer months, but incidence is rare. Most U.S. sightings
are around Florida and Texas and they are much less common than
the larger Loggerhead sea turtle (Caretta caretta). They
are most commonly found in hard-bottomed and reef habitats containing
coral and sponges. They also reside in shoals, lagoons of oceanic
islands, and continental shelves. In general, they are found in
water no deeper than 60ft. When hawksbill turtles are young, they
are unable to dive into deep water, and live around masses of
floating sea plants, such as sargassum.
Habits: Adults feed on fish, gastropods, echinoderms (sea
urchins), and in particular, sponges. A throat lined with spines
aids in digestion of sponges. Their feeding on sponges causes
succession to occur in reefs by freeing up space for the settlement
of new organisms. A long-lived species, the hawksbill can live
past 100 years of age, although not much is known about their
development in the first 20-30 years of their lives. They are
nocturnal in nesting behavior and normally laying between 3-5
clutches of eggs in a nesting season. Studies have shown that
hawksbills are prone to return to the beach in which they were
born, although evidence of how or why this occurs is lacking.
Some suggest that magnetic fields and lunar positions play a key
role in this behavior. Hawksbill turtles are pan-tropical in distribution
and nest on islands and mainland beaches located between the Tropic
of Capricorn and the tropic of Cancer.
Conservation Status: The Hawksbill meets the 1996 IUCN
Red List criteria for a Critically Endangered species, based on
global population declines of more than 80% over the last 100
Miller, Jeffrey D. 1997. Reproduction in Sea Turtles. pp.51-81
In: Lutz, P.L. and Musick, J.A. (Eds). The Biology of Sea
Turtles. CRC Press, Boca Raton, FL.
Meylan, Anne B. and Marydele Donnelly. 1999. Status Justification
for Listing the Hawksbill Turtle (Eretmochelys imbricata)
as Critically Endangered on the 1996 IUCN Red List of Threatened
Animals. Chelonian Conservation and Biology 3(2):200-224.
Author Account: Geoffrey Bailey, University of Georgia
- edited by J.D. Willson