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Olive Ridleys show up only rarely along the Californa coast.
One appeared on the beach shown above in Tamales Bay, Marin County, in November of 2002. There just happened to be a biologist with a Seaturtle protection organization vacationing there with his family. He was able to identify the turtle and take some pictures.
A picture and information about this rare occurrence is available on the
Sea Turtle Restoration Project website.
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Links to more photos of Olive Ridleys:
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Arribada Photo:
Marine Conservation Society |
Arribada Film:
Marine Conservation Society
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| Description |
| Size |
| The smallest (and most numerous) sea turtle in the world. Adults are 20 - 29 inches in shell length (51 - 74 cm) 0 - 100+ lbs. (Stebbins 2003) |
| Appearance |
| A small sea turtle with a round, flat carapace, a large, triangular head, and an olive to grayish green carapace. The skin is gray, and the plastron is light greenish yellow or whitish. There are two pairs of prefrontals, and usually 5 - 9 costal shields on the sides, the first pair coming into contact with the nuchal. Males have longer thicker tails than females and well-developed curved claws on the forelimbs. |
| Behavior and Natural History |
| Little is known about Olive Ridley behavior other than nesting behavior. They undertake long migrations to and from nesting beaches. Large numbers are sometimes seen basking at the surface. |
| Diet |
| Mostly carnivorous. Eats mollusks, crustaceans, jellyfish, sea urchins, crab, fish, sea urchins, snails, jellyfish, and occasional plant material - algae, seagrass, and seaweed. |
| Reproduction |
Olive Ridleys found in our area derive from eggs laid from May through January from Costa Rica to Baja California. Nesting occurs in some part of its range in almost every month of the year.
Olive Ridleys nest together in synchronized mass nesting called "arribadas" which may consist of thousands of females nesting at the same time. From 20,000 to 200,000 females may visit a nesting beach in one season.
Tropical beaches and barrier islands, often near river mouths, are preferred.
Many females reproduce every year, but some nest every 2 - 3 years, usually from 1 - 2 times per season, every 14 - 30 days.
Nesting occurs mostly at night, but diurnal nesting also occurs. A female crawls onto the nesting beach, scoops a body pit, then digs a nest and lays a clutch of 30 - 170 eggs, which she covers with sand before crawling back into the ocean. The whole procedure takes less than an hour. Nests are robbed by a variety of predators including humans, pigs, opossums, racoons, coyotes, coatimundi, caimans, and snakes. The eggs hatch in 45 - 70 days depending on the weather and temperature. Hatchlings emerge and begin a frantic race to the sea, chased by predators such as crabs, vultures, and seabirds. Once they reach the water they are still in danger from predators such as sharks, fish, and crocodiles. |
| Range |
Found in tropical waters of the Pacific and Indian Oceans, including Arabia, Japan, Micronesia, off the west coast of Africa, the north and east coasts of South America, occasionally in the Caribbean, from Chile north to the Gulf of California, occasionally straying as far north as Oregon and possibly Alaska during warm-water El Niño years.
Locations where Olive Ridleys have been seen in California waters include Point Loma, La Jolla, and Encinitas in San Diego County, near Noyo in Mendocino County, and near Table Bluff in Humboldt County. |
| Habitat |
| Marine. Found well out to sea and in protected, relatively shallow bays and lagoons and the shallow water between reefs and the shore. |
| Taxonomic Notes |
| No subspecies are recognized. |
| Conservation Issues (Conservation Status) |
Endangered.
Although it is the most numerous species of sea turtles, Olive Ridley populations are declining. Nesting no longer occurs on some formerly heavily-used beaches. Eggs and turtle flesh are eaten by humans and the hide is used for leather, with turtles often slaughtered on or offshore of the nesting beaches during the nesting season, contributing to a decline in reproduction.
Other causes for the decline of sea turtles include the development and degradation of nesting beaches, degradation of feeding habitats, entanglement of turtles in fishing nets, including discarded nets, and 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 |
Lepidochelys |
Ridley Sea Turtles |
Species
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olivacea |
Olive Ridley Sea Turtle |
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Original Description |
Lepidochelys olivacea - (Eschscholtz, 1829) - Zool. Atlas, Pt. 1, p. 2, pl. 3
from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz
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Meaning of the Scientific Name |
Lepidochelys - Greek - lepido - scaled, and chelys - turtle
olivacea - Latin - olive olive green, and -acea - having the nature or color of - probbly refers to the color
from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz
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Alternate Names |
Olive Ridley
Pacific Ridley
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Related or Similar California Turtles |
C. caretta - Loggerhead Sea Turtle
C. mydas - Green Sea Turtle
E. i. bissa - Pacific Hawksbill Sea Turtle
D. coriacea - Leatherback Sea Turtle
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More Information and References |
Natureserve Explorer
California Dept. of Fish and Game
NMFS
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.
Lemm, Jeffrey. Field Guide to Amphibians and Reptiles of the San Diego Region (California Natural History Guides). University of California Press, 2006.
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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, which indicates that there are no significant conservation concerns for it in California, however it is endangered worldwide.
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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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