Loggerhead Turtle & Costa Rica

Loggerhead turtles nest only sporadically at Turtle Love’s project site. In addition to a large head in comparison to body size, loggerheads get their names because they are commonly found resting on the bottom of the coastal seas or bobbing on the surface, like a log. This passive behavior creates an opportunity for commensalism.

Commensalism is an ecological relationship in which one of the organisms benefits from whereas the other does not benefit from or is harmed by the interaction, and loggerheads host a lot of commensal species. Several species of barnacles, colonial hydroids, shelled mollusks, sea urchins, small and large crabs, and many species of algae all inhabit a loggerheads outer body, especially its shell.

Of all those tenants, the Columbus crabs (Planes minutus) provide an interesting example of loggerhead commensals. Check out this video from BBC’s documentary Planet Earth II.

Scientific name

Caretta caretta

Common names

English: Loggerhead

Spanish: Cabezona, Tortuga boba, Caguama

Portuguese: Tartaruga-cabeçuda

Size and weight

Adults typically measure around 90 to 110 cm (35 to 43 in) in carapace length and weigh between 70 to 170 kg (150 to 380 lbs).

Distribution

Loggerheads inhabit temperate and tropical waters of all ocean basins. Most nesting occurs on warm temperate sandy beaches. This species nests only sporadically at Turtle Love’s project area.

Reproduction

Female loggerhead sea turtles reproduce approximately every two to four years, whereas males may reproduce annually. Every nesting season, female loggerhead will lay between 3 and 6 nests at two-week intervals. These nests will typically contain around 115 eggs.

In Costa Rica, the Loggerhead Turtle appears along the Caribbean between the months between May and August. A good place to see them is Tortguero and occasionally Barra de Pacuare.

Diet

Jellies, sponges and hard-shelled crustaceans and mollusks

Identifying features

Appearance

Adult loggerheads have a massive head in comparison to body size, especially males, which gives the name of the species. This feature is supposed to be due to the need to attach strong jaw muscles that are important to break the hard shells of their main prey items.

As mentioned earlier, loggerhead bodies are also scuffed and rough and full of commensal species. An adult loggerhead’s shell will usually be covered with barnacles and algae.

Color

Shell coloration may be occulted by algae and barnacles, but the overall color of an adult loggerhead turtle is a brownish red.

Scales and claws

This species is distinguished from the other hard shelled sea turtles by having five pairs of lateral scutes on their shells, with the pair of lateral scutes closest to head touching the nuchal, marginal scute. Furthermore, loggerheads have two claws on both rear and front flippers.

Conservation status

Loggerhead turtles are listed as globally vulnerable by the IUCN Red List of Threatened Species, though the northwest Atlantic subpopulation, which includes individuals nesting at Turtle Love’s project area, is considered of least concern.