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Captive rescued juvenile from the Gulf of Mexico. Sea Turtle Rescue Center, Sea Turtle Inc., South Padre Island, Texas.
I have no pictures yet of the Pacific subspecies of this sea turtle. This is the Atlantic subspecies of Hawksbill Seaturtle, E. i. imbricata, which is similar in appearance to the Pacific Hawksbill - E. i. bissa, which occurs in California. |
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Close-up of shell of captive juvenile shown above. |
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Stuffed and mounted Adult, Santa Barbara Museum of Natural History |
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Hawk-shaped bill |
Habitat in California, the Pacific Ocean
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| Description |
| Size |
| Adults are 18 - 36 inches in shell length (46 - 91 cm) and 30 - 280 lbs. (Stebbins 2003) |
| Appearance |
A small to medium-sized sea turtle with paddle-like limbs, a heart-shaped carapace with a central keel and a serrated rear edge. The shields overlap like shingles, except in hatchlings and very old animals. There are two pairs of prefrontal scales, and 4 costal shields on each side of the carapace. The first costal shield does not touch the nuchal. A long, narrow, sharp snout, like that of a hawk, gives this turtle its common name, Hawksbill.
Color is a dark greenish brown with a marbled or radiating pattern. The plastron is yellow and hinge-less. The head scales are black to chestnut brown in the center, with lighter margins. The chin and throat are yellow.
Males have a long tail that extends well past the edge of the shell and a curved nail on the front of each flipper. |
| Behavior and Natural History |
| Not much is known about Hawksbill behavior due to their solitary habits. They are apparently diurnal, becoming nocturnal when nesting. Hawksbills sleep at night on the bottom, surfacing occasionally for air. They will readily bite to defend themseves. Hawksbills are possibly the least migratory of sea turtles, but some tagged individuals have been recorded traveling long distances. As with other sea turtles, the yearly activity during the breeding year of a Hawksbill includes a long period of foraging, migration to nesting beach, nesting, and migration back to the feeding grounds. |
| Diet |
| Omnivorous. Feeds upon many invertebrates, preferring sponges (including toxic sponges) in some areas, mollusks, jellyfish, corals, sea anemones, sea urchins, crabs, rock lobster, fish, algae, sea grasses, and mangroves. |
| Reproduction |
Hawksbills mate in shallow water off the nesting beach and nest individually, not in large groups like other sea turtles. In the Pacific, nesting has been observed in Ecuador, Panama, Costa Rica, Nicaragua, Guatemala, El Salvador, Mexico, and occasionally in Hawaii.
Females nest every 2 - 3 years between August and November at an average of 4 - 5 times per season. Sheltered, short, steep sandy beaches are preferred, and nests are often dug in the sandy soil among vegetation instead of open sand.
A female Hawksbill emerges from the ocean at night and crawls onto the nesting beach, using all four limbs to rapidly walk over the sand, instead of using just the two forelimbs to pull herself as other sea turtles do. She scrapes out a shallow body pit, then digs a nest and lays a clutch of 50 - 200+ eggs. Her total time on the beach is 1 - 2 hours. Nests are robbed by humans, and other mammals such as dogs, raccoons, and rats. The eggs hatch in 60 - 70 days and hatchlings emerge in the morning or in the evening and begin a frantic crawl towards the water. Hatchlings trying to get to the sea are eaten by birds, crabs, and other predators, and again by fish, octopus, sharks, and others once they reach the water. |
| Range |
I have not yet found any records of sightings of Pacific Hawksbill Seaturtles in California waters. The only museum specimen from California I can find is from the Utah Museum of Natural History which is labelled as coming from the Hermosa Reptile and Wild Animal Farm, Hermosa Beach. There is no indictation if the specimen was collected in California. The species is included here because sources such as California's endangered animals list, Robert Stebbins' 2003 field guide, and Ernst, Lovich, and Barbur (1994) state that this species has been found in Southern California waters.
The Hawksbill species is found in the warmer parts of the Pacific, Indian, and Atlantic oceans. In the eastern Pacific, it is found from southern California to Peru. It is found infrequently in the Mediterranean Sea.
The subspecies found in our area E. i. bissa, the Pacific Hawksbill, is found in the tropical parts of the Indian and Pacific oceans, from Madagascar to the Red Sea, east to Australia, Japan and the Hawaiian Islands, and in the eastern Pacific from Peru to Baja California. Stragglers occasionally stray north to Southern California waters, probably during El Niño years when ocean temperatures rise. |
| Habitat |
| Inhabits shallow coastal waters in rocky places, coral reefs, mangrove-bordered bays, estuaries, and mud-bottomed lagoons. Sometimes found in deep water. Juveniles float on currents with patches of Sargassum weed. |
| Taxonomic Notes |
| Two subspecies are recognized - Eretmochelys imbricata bissa - Pacific Hawksbill, and Eretmochelys imbricata imbricata - Atlantic Hawksbill. |
| Conservation Issues (Conservation Status) |
Endangered.
Getting accurate estimates of Hawksbill population numbers is difficult due to their behavior of nesting individually on scattered beaches. This behavior also makes assisting their reproductive success with nesting preserves ineffective.
Hawksbills have been in demand for their meat, their eggs and the translucent scutes of their shell, from which "tortoiseshell" products are made. They also suffer mortality through entanglement in fishing lines and nets, oil spills, and possibly from the development and degradation of nesting beaches, which is a worldwide problem with other species of sea turtles.
Other causes for the decline of sea turtles include the degradation of feeding habitats, ingestion of plastic garbage, especially plastic grocery bags (which look like jellyfish floating on the surface) and offshore boats moving so quickly that turtles are not able to move out of the way fast enought to avoid being killed or injured. Some authorities also question whether humans handling nesting females and doing research on nesting beaches is stressing the turtles and lowering reproduction and survivorship. |
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Taxonomy |
| Family |
Cheloniidae |
Sea Turtles |
| Genus |
Eretmochelys |
Hawksbill Sea Turtles |
| Species |
imbricata |
Hawksbill Sea Turtle |
Subspecies
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bissa |
Pacific Hawksbill Sea Turtle |
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Original Description |
Eretmochelys imbricata - (Linnaeus, 1766) - Syst. Nat., 12th ed., Vol. 1, p. 350
Eretmochelys imbricata bissa -(Ruppell, 1835) - Neue Wirbelthiere zu de Fauna Von Abyssinien Gehorig, Vol. 3 , Amph., p. 4, pl. 2
from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz
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Meaning of the Scientific Name |
Eretmochelys - Greek - eretmo - oar, and chelys - turtle - refers to the shape of the forelimb
imbricata - Latin - overlapping - probably refers to the scute pattern
bissa - Latin - bis - double, twice, and -sa suffix - refers to the concept of bissa as second species of Caretta
from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz
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Alternate Names |
Hawksbill
Pacific Hawksbill
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Related or Similar California Turtles |
C. caretta - Loggerhead Sea Turtle
C. mydas - Green Sea Turtle
L. olivacea - Olive Ridley Sea Turtle
D. coriacea - Leatherback Sea Turtle
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More Information and References |
Natureserve Explorer
California Dept. of Fish and Game
USFWS
Turtles.org
Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians. 3rd Edition. Houghton Mifflin Company, 2003.
Behler, John L., & F. Wayne King. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, 1992.
Carr, Archie. Handbook of Turtles: The Turtles of the United States, Canada, and Baja California. Cornell University Press, 1969.
Ernst, Carl H., Roger W. Barbour, & Jeffrey E. Lovich. Turtles of the United States and Canada. Smithsonian Institution 1994.
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The following status listings come from the Special Animals List which is published several times each year by the California Department of Fish and Game.
This turtle is not included on the Special Animals List, maybe because it is not considered a species that occurs in California. It is considered to be critically endangered by the World Conservation Union.
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Organization
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Status Listing
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| U.S. Endangered Species Act (ESA) |
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| California Endangered Species Act (CESA) |
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| California Department of Fish and Game |
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| Bureau of Land Management |
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| USDA Forest Service |
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| Natureserve Global Conservation Status Ranks |
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World Conservation Union - IUCN Red List
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CR |
Critically Endangered |
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