Biology of Sea Turtle...

Sea turtles are graceful saltwater reptiles, well adapted to life in their marine world.
With streamlined bodies and flipper-like limbs, they are able to navigate across the oceans. From eight species of sea turtle found worldwide, five species can be found in Thai waters: Leatherback turtle, Green turtle, Hawksbill turtle, Olive ridley turtle and Loggerhead turtle.

Leatherback Turtle
Characteristic: Black shell with 7 longitudinal ridges on the carapace. No scutes on shell of adult.
Size: This is the largest living turtle. The average curved carapace length is 155 cm and weight ranges from 200-700 kg.
Diet: Carnivorous; especially jelly fish
Nesting Ground (Thailand): Andaman seashore

Green Turtle
Characteristic: Yellowish-brown carapace with pattern similar to sunshine. (Called in Thai as
sunshine turtle)
Size: This is the largest of the hard-shelled sea turtles. The average curved carapace length is 100 cm weight can be up to 180 kg.
Diet: Herbivorous; sea grass and algae.
Nesting Ground (Thailand): Gulf of Thailand and Andaman seashore

Hawksbill Turtle
Characteristic: Overall appearance similar to that of Green turtle but scales overlap and tip of the beak looks like hawk’s beak.
Size: The average curved carapace length is 90 cm., weight can be up to 80 kg.
Diet: Omnivorous; Sponges, mollusks and algae.
Nesting Ground (Thailand): Gulf of Thailand and Andaman seashore

Olive Ridley Turtle
Characteristic: Has smooth carapace with gray-ish-green color with sharp beak.
Size: This is the smallest sea turtle, the average curved carapace length is 65 cm., weight can be up to 60 kg.
Diet: Omnivorous; crustaceans and mollusks.
Nesting Ground (Thailand): Andaman seashore

Loggerhead Turtle
Characteristic: General features are similar to Olive ridley but shell color is similar to Green turtle without pattern.
Size: The average curved carapace length is 92 cm., weight can be up to 115 kg.
Diet: Omnivorous; crustaceans and mollusks.
Nesting Ground (Thailand): None

Gender Differentiation
Female: Short tail Male: Elongated tail
Nesting Biology...

Over the course of a nesting season, sea turtles will leave their homing ground and migrate to resting grounds to build a nest and lay eggs.

Nesting Behavior

Courtship activity usually occurs several weeks before the nesting season. It can take place either on the surface or under water. Males may court a female by nuzzling her head or by gently biting the back of her neck, which a single female may court with two or more males. The fertilization is internal.

Beach Selection
Female turtle would choose to lay eggs on sandy and quiet beaches at night. Most females return to the same beach each time they are ready to nest, moreover, they often emerge within a few hundred yards of where they last nested.

The female turtle crawls to a dry part of the beach and begins to flings away loose sand with her flippers. She then constructs an egg cavity using her cupped rear flippers as shovels. The egg cavity is shaped roughly like a tear drop. When the turtle has finished digging the egg chamber, she begins to lay eggs. The average size of a clutch ranges from about 80 to 120 eggs, depending on the species. The female then covers the nest with sand using her hind flippers. Nesting sea turtles appear to shed tears, but the turtle is just secreting salt that accumulates in her body.

Incubation takes about 60 days. Essentially, the hotter the sand surrounding the nest, the faster the embryos will develop. Cooler sand has a tendency to produce more males, with warmer sand producing a higher ratio of females. Hatchlings usually emerge from their nest at night. Once they decide to burst out, they erupt from the nest cavity as a group. The little turtles orient themselves to the brightest horizon, and then dash toward the sea.


Threats to Sea Turtle...

Sea turtles are beautiful, efficient animals that travel the world's oceans and know to return to the beach where they were born to lay their eggs. They have been in existence for millions of years and flourished until the last 100 years when they became endangered, mostly by human activities.

Major threats that have brought all species of sea tur-tles to the edge of extinction are:
• large-scale poaching of adult turtles for meat, shells and leather
• commercial exploitation of sea turtle eggs
• drowning of sea turtles in fishing nets
• development and destruction of nesting beaches
• pollution of the oceans

Patong beach, Thailand, used to have thousands of hatching turtles every year, but it just the history. How can mother turtles find the places for their babies on this crowed beach?
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