Sea Turtle Life Cycle
The Life of Sea Turtles
Posted May 2017
Sea Turtles live a solitary life in the oceans until they reach sexual maturity. At sexual maturity they are ready to mate, a stage decided by either age or size, or both.
Deciding Maturity by Age
Specie Age of Sexual Maturity(Years)
Green Sea Turtles 20-50
Deciding Maturity by Size
Specie Size at Sexual Maturity
Loggerheads 80 cm – 90 cm (30 in – 35 in)
Hawksbill 60 cm – 95 cm (24 in -37 in)
Green Sea Turtles 69 cm – 80 cm (27 in to 30 in)
Sea Turtle Partner Selection
Though polygamous, females can be choosy when selecting their partner, albeit one-at-a-time, from a batch of several suitors. She courts only one during a courtship that involves ‘flipping-off’ all undesirable males, before positioning herself to receive the lucky chap. Mating takes place in the shallows of the shoreline. Scuba divers and snorkelers often view them during courtship, but are careful to avoid amorous males.
The male attaches himself to the female’s carapace by latching onto its front with claws on his front flippers. His tail has another claw that will latch him to the back of her carapace. Once clamped securely to her shell he begins his penetration of her orifice; they display little movement during the mating.
Other males will be anxiously circling, trying to get in on the act. They will try to shove off the lucky suitor.
During this romance, it is up to the female to swim them both to the surface for a quick exchange of air. This interlude will go on for hours; sometimes as long as half-a-day. After she retains the sperm collected from males in her oviducts, a pouch built for the purpose. At some later date she can impregnate herself at will.
The Male’s Role
After servicing the female, the male plays no other role in the family-life. The male’s sole purpose is for reproduction.
The Female’s Role
Females have cleverly hidden the answer to the question, ‘how long does their gestation last?’ Because they live in the sea and only come ashore to nest, no one is really sure how long she carries her eggs for before nesting. Monitoring indicates some species have a gestation period of two weeks; others two years.
When the female is ready to nest she comes ashore where she hatched. She digs the hole for the nest; the actual depth is limited to the length of her rear flippers. It is between 35 cm – 56 cm (14 in – 22 in) in depth, she then lays her eggs.
Sea Turtles lay a ‘clutch’ of 60 to 200 eggs; each egg is about the size of a ping-pong ball and is slightly elliptically. Females can nest 4 to 6 time per season, and ‘nesting’ occurs every 2-4 years.
She deposits a gelatinous secretion in the ‘clutch’ to keep the eggs moist and protected. Eggs laid, she carefully paddles the sand back over them to further protect, conceal, and control the internal temperature of this incubator. Her job completed, she makes her way back to the ocean until it is time to nest again; she will return.
The eggs incubate in the warm sands for a few weeks (45 –60 days) before hatching.
After breaking free of its shell, each hatchling is about 6.35 cm (2.5 inches) long and weighs about 28.35 gm (1 oz.).
Less than 1% of the eggs will survive and make it to the sea. Between 20% and 40% of them will be yoke-less or undeveloped and the others will be victims of predators.
- Man- for consumption; aphrodisiac; financial gain; crushed by beach activities
- Raccoons, Crabs, Insects
- Beach Debris
Sea Turtle Nesting Locations
The ideal nesting beaches are made of soft sands gently sloping from the sea.
Wildlife Refuge Parks were established on Costa Rica’s coastline to protect the many Sea Turtle nests there. The Blue River Resort and Hot Springs organizes tours to the Ostional National Wildlife Refuge upon request. The Rangers at Playa Ostional begin the tour with a very interesting introduction for visitors. They explain the procedures and prepare visitors for the experience of a lifetime. Children are always fascinated by the hatchling, for them it is a life-altering experience; they come away with a new appreciation for the environment.
Playa Ostional is the most popular turtle watching beach in Costa Rica. Guests are guaranteed to see the Olive and Kemp’s Ridley Sea Turtles and other species depending on the time of year. The Blue River Resort’s Tours will get you there.
Costa Rica Sea Turtles...
- Not Tortoises! Sea Turtles! – What’s the difference?
- Sea Turtles Then and Now
- Costa Rica’s Sea Turtle Population Threat
- Fun Facts About Sea Turtles
- Costa Rica Sea Turtle Species
- Back to Introduction: Sea Turtles in Costa Rica
- Book OurTour: Ostional Sea Turtle Nesting Adventure
- The individual species and their peculiarities.
- Threats to Turtles and Other Marine Species
- Sea Turtle Conservation
- The Conservationists
- Counting Sea Turtles is Not Easy
- New Ways of Counting