Saturday, June 8, 2019

Olive Ridley Sea Turtle

Another species of turtle we saw at the Sea Turtle Conservation Project in Koggala was the olive ridley sea turtle, also known as the Pacific ridley sea turtle. There are an estimated 800,000 nesting  individuals, the most of any sea turtle species, and it is listed as Vulnerable by the IUCN Red List. It is the second smallest sea turtle. There is a related species called the Kemp's ridley sea turtle, also known as the Atlantic ridley sea turtle, which is a member of the same genus, but a different species. There are only 7,000 to 9,000 nesting individual Kemp's, the smallest species and also listed as Critically Endangered by the IUCN Red List. 
Olive ridley distribution map. Red circles are major nesting grounds and yellow circles are minor nesting beaches. Note that Sri Lanka is a major nesting ground. 
As the name suggests, the olive ridley is found primarily in the Pacific and Indian Oceans, but can also be found in the warm waters of the Atlantic. The Kemp's ridley is found in the western Atlantic and Gulf of Mexico and the vast majority all the females return to one beach in Mexico, Rancho Nuevo, in Tamaulipas, to lay eggs (see this great article about it).
Sea turtle eggs in a jar.
Sea turtle eggs, marked by species, in the sand. 
The olive ridley is the most common sea turtle in Sri Lanka, or at least on the south coast where we were. The olive ridley is named for the greenish color of its skin and shell, although growing algae can give it a reddish appearance. Adults are a dark gray green, juveniles are charcoal gray and hatchlings are black when wet with greenish sides. They are solitary, but come together as a group once a year for the females to return to the beaches where they hatched and come ashore to rest. Females lay about a hundred eggs and may nest up to three times a year. The shell, or carapace, is bony without ridges and has large scutes (scales). 
We got to hold these young olive ridley turtles, about a day old. 

We also got to hold an adult turtle - I'm not positive, but I believe this is an olive ridley as well. 

1 comment:

  1. That turtle looks like it has a zipper on its tummy so that it can take its shell of if it wants to.