By Alex Navarro
Learn about these wonderful creatures that are born here on our beautiful Baja beaches!
All About Turtles:
- The earliest turtles date from the Middle Jurassic period and are more ancient than snakes or crocodilians. By counting the rings formed and stacked on the shells it is possible to estimate aproximately the age of a turtle.
- The largest living turtles are the leatherback sea turtles (Dermochelys coriacea), which can be 6.6 feet in length and weigh 2,000 pounds. The largest ever known turtle was Archelon ischyros from the Late Cretaceous period and was up to 15 feet long. The smallest turtle is the speckled padloper tortoise of South Africa which is 3.1 inches in length.
- Turtles have bony or cartilaginous shells that act as a shield. The upper shell is called the carapace and the lower shell is called the plastron. Depending on the species the color of shells may vary from brown, black, or olive green; to red, orange, yellow, or also grey markings, spots, lines and markings.
- Turtles are cold-blooded and are classified as amniotes like other species of reptiles, birds, and mammals that live in or around water, which means they breathe air and do not lay eggs underwater.
- The main difference between a turtle and a tortoise is that a turtle may be limited to only aquatic species, and a tortoise usually refers to any land-dwelling, non-swimming "chelonian" (turtle). Tortoises have heavy shells, in contrast, aquatic turtles have light shells to avoid sinking, and for swimming faster and with more agility.
- The vertebrae of turtles have an S-shaped curve to allow for neck retraction back into the shell. And depending on how they retract their necks into their shells, turtles are divided into two groups: the suborder Pleurodira retracts the neck to the side and anterior to the shoulders, and the suborder Cryptodira retracts the neck straight back, between the shoulders.
- Turtles have strong jaws and rigid beaks to cut and chew food. Carnivorous turtles have sharp ridges for slicing through their prey, and herbivorous turtles have serrated ridges to cut through plants. Turtles can´t stick out their tongues to catch food. Sea turtles usually feed on jellyfish, sponges, and other soft sea foods.
- All sea turtles breathe air and must surface at regular intervals to refill their lungs.
- Terrestrial tortoises have short, sturdy feet. Amphibious turtles have feet that are webbed. Sea turtles have flippers instead of feet.
- Turtles have color vision and exceptional night vision.
- Turtles make sounds when communicating. Some vocalizations serve to create group cohesion when migrating. Tortoises are vocal when courting and mating.
- Turtles lay eggs that are soft and leathery. In some species, temperature determines whether an egg develops into a male or a female. Eggs are put in holes dug in the mud or sand and then they are covered and left to incubate. A sea turtle’s nest may contain up to 200 eggs. Depending on the species, eggs will take about 50 to 100 days to hatch. When hatching, the baby turtles (hatchlings) emerge from their shell and head towards the sea. During their crawl to the ocean they can be eaten by birds, crabs, raccoons, dogs or other predators, and more risks await them at sea. One of a thousand baby turtles will reach adulthood.
- Sea Turtles live most of their lives at sea and mate at sea too. Females return to the precise location where they were born to lay their eggs. It is thought that they use the Earth’s magnetic field as a means of navigation. Males, on the contrary, never set foot on land again after being born.
- Sea turtles land on the beaches of Mexico between June and November each year. In the Pacific Coast they mainly arrive in Mazatlan, Costalegre, Puerto Vallarta, Manzanillo, Oaxaca and Baja California Sur (San Jose del Cabo and Cabo San Lucas); and in the Atlantic Coast in Yucatan (Akumal and Rio Lagartos).
- Mexico is considered as the country of sea turtles. Seven species of turtles reproduce here: Green turtle (Chelonia mydas), Loggerhead turtle (Caretta caretta), Hawksbill turtle (Eretmochelys imbricata), Leatherback turtle (Dermochelys coriacea), Black turtle (Chelonia agassizi), Olive Ridley turtle (Lepidochelys olivacea), and Kemp's Ridley turtle (Lepidochelys kempii). The only one that does not nest in Mexico is the Australian Kikila turtle (Chelonia depressa).
A LITTLE BIT OF SCIENCE:
- Kingdom: Animalia; Subkingdom: Bilateria; Infrakingdom: Deuterostomia;
- Phylum: Chordata; Subphylum: Vertebrata; Infraphylum: Gnathostomata;
- Superclass: Tetrapoda; Class: Reptilia;
- Order: Testudines; Suborders: Cryptodira, Pleurodira;
- Families: Emydidae (pond, box, Blanding’s, painted, spotted, and chicken turtles); Platysternidae (big-headed turtles); Testudinidae (tortoises); Geoemydidae (Asian river turtles, leaf and roofed turtles, Asian box turtles); Kinosternidae (mud and musk turtles); Dermatemydidae (Mesoamerican river turtle); Trionychidae (softshell turtles); Carettochelyidae (pignose turtle); Cheloniidae (loggerhead, ridley, hawksbill, and green sea turtles); Dermochelyidae (leatherback turtle); Chelydridae (snapping turtles); Chelidae (snake-necked turtles); Pelomedusidae (side-necked turtles); Podocnemididae (Madagascan big-headed turtles and American side-necked river turtles);
Genera and species: (there are 75 genera and about 365 species).
Sea Turtles in Baja:
Five species of sea turtles (Hawksbill, Loggerhead, Leatherback, Green Turtle and Olive Ridley) are found along Mexico's Baja California peninsula. Some nest in The East Cape of Los Cabos. The Olive Ridley, also known as the golfina, nests there from June to December. The golfina can grow 26 inches long and weigh 90 pounds. The leatherback, nests there from November through February and can grow to 70 inches long and weigh 1,300 pounds.
Turtle release: from July to October you can participate during the nesting season (egg laying) of the turtles in, and during the hatching season (turtle releasing) from September to December. These activities take place at many different beaches of Cabo and on the Pacific Side too. A great place to reach out to find out about participating is ASUPMATOMA, A.C. (Southern Baja California Association for the protection of the environment and sea turtles of Los Cabos) via email at firstname.lastname@example.org or call (624) 143 0269. Throughout 23 seasons of work they have protected around 12,000 olive ridley turtle nests and released to the sea more than 1,000,000 baby turtles. From July to January they have nightly patrols to protect the nesting turtles and to relocate nests to incubation sites to ensure the largest number of offspring turtles make it to the ocean.
Final fun fact: many times turtles have 13 patches on their shells, making it a symbolic animal for the 13 moons in a yearly cycle. *