Sea turtles lay their eggs on the beaches and lower dunes of coastal nesting habitats. Nesting habitats or nesting grounds refer to the locations where sea turtles lay their eggs.
Here these chelonians can lay up to 200 eggs per nest and up to 8 nests each nesting season. A nesting hawksbill can lay up to 200 eggs a night.
While sea turtles nest on beaches across the world, different turtles nest in different locations. Regardless of the locations, sea turtles tend to nest on the shores of tropical and subtropical oceans.
For instance, the olive ridley generally nests between the latitudes 40 degrees north and 40 degrees south.
Choosing The Nesting Site
Sea turtles generally return to their natal beach to lay eggs. The natal beach refers to the beach where the turtle hatched.
However, turtles do not always return to their natal beach. A nesting female may decide to nest at a different beach. Regardless of whether or not the turtle returns to its natal beach.
The nesting site of sea turtles is beaches above high tide levels – that way the eggs do not end up being covered by water. When covered by water, the embryo within the egg is unable to breathe and dies.
The nesting site should be sandy with little to no vegetation. If there is vegetation on the nesting beach this is usually low-density herbaceous vegetation.
Sea turtles tend to lay eggs in the tropics and subtropics. As such, the beach where the turtle lays the eggs have to be warm. Temperate beaches are ignored as the temperatures there are too high for proper incubation of the eggs.
According to research done by a research team from the University of North Carolina, turtles can return to their natal beach as the magnetic field of the beach is imprinted on the hatchlings. As adults, the turtles can find the magnetic signature of the beaches they where they hatched.
Similar to many other animals that travel long distances, the sea turtle uses the earth’s magnetic field for navigation.
Loggerhead Sea Turtles
The loggerhead turtle is one of the largest sea turtles out there and is regarded as the largest hardshell sea turtle.
This reptile can be found throughout the world’s subtropical and temperate waters. This turtle can be found in the Atlantic, the Indian, and the Pacific Oceans as well as the Mediterranean Sea.
Similar to the other turtles, this turtle lay their eggs on the beach, specifically mainland and insular sandy beaches, of their nesting habitats.
This turtle can large up to 6 nests per nesting season and lay about 100 to 126 eggs per nest.
The largest nesting habitat of the loggerhead is Florida where nesting females lay over 67,000 nests and with each nest having 100 to 126 eggs. This means about 7 million eggs are laid in Florida every year.
Apart from Florida, the turtles nest from Florida to Virginia in the north and to Brazil in the south. Cape Verde Islands also host significant numbers of nesting females every year.
In the Indian Ocean, the species nest along the coast of the Arabian sea, the Arabian peninsula, and the African continent. In Africa, the loggerheads nest from the St Lucia estuary in south Africa to Bazaruto Archipelago in Mozambique.
Other popular places where the loggerhead lays eggs include Oman where about 15,000 nests can be found yearly. Another significant nesting site in the Indian Ocean is the western Australian coast where loggerheads lay about 2000 nests every year.
In the Pacific, the species nest in Japan, specifically Yakushima Island. The species also nest in the Great Barrier Reef of Australia.
The Mediterranean sea’s coastlines are home to several nesting sites. Some of the more popular nesting sites include Zakynthos and Kyparissia in Greece and the coastlines of Turkey and Cyprus.
Kemp’s Ridley Sea Turtles
Two turtles are in the genus Lepidochelys and one of them is the kemp’s ridley.
This turtle is one of the smallest sea turtles with a length of 22 to 30 inches or 55 to 75 cm. While this is still large when compared to other turtles, they are still considered the smallest in length overall.
As already meant, the turtle nest on the beaches of its nesting habitats. Unlike other turtles.
The places where this sea turtle nest is quite limited. Also, every kemp’s ridley nests in the Gulf of Mexico, stretching from the Florida peninsula to the Yucatan peninsula.
The main nesting of each of the species can be found near Rancho Nuevo in Mexico. This is located in the western Gulf of Mexico.
There are also nesting beaches in Veracruz, Tamaulipas, and texas. These are all locations where the kemp‘s ridley lays eggs.
The kemp’s ridley is one of the turtles that are associated with the arribada. This is when hundred to thousands of nesting females simultaneously arrive at nesting beaching to lay eggs.
With the kemp‘s ridley, this occurs in beaches found around the Mexico-Texas border in places such as Padre Island National Seashore, and Tamaulipas, Mexico.
The nesting turtles use their font flippers to dig a hole. Initially, this whole is large enough so that the carapace is at the same level as the sand on the beach.
The nesting female then uses the back legs to dig the hole into which to lay the eggs. After the turtle lays the eggs, the turtle uses the back flippers and her plastron to over the hole and hide the nest.
Olive Ridley Sea Turtles
The olive ridley can be found in the Pacific, Atlantic, and Indian Oceans, unlike the kemp’s ridley which is only endemic to the Atlantic Ocean. For this reason, the kemp’s ridley is often called the Atlantic ridley, and the olive ridley is called the Pacific ridley.
This turtle isn’t particularly large. Its size is similar to that of the kemp’s ridley. This turtle can weigh as much as 100 lbs or 45 kg and reach a length of about 30 inches or 75 cm.
This turtle is generally found in the subtropics and the tropics and is generally located within the latitudes of 40 degrees north and 40 degrees south. This is actually common among turtles.
So where exactly do olive ridley lay eggs? The species is known to lay eggs on beaches of the Indian Ocean, and the Pacific Ocean.
In the Indian Ocean, the most significant nesting site can be found on the coast of Odisha in India, in specific in Gahirmatha. Here, a hundred thousand turtles nest.
Here, the nesting is synchronized and huge. On the Coromandel Coast in India and in Sri Lanka, many slidably nesting females lay eggs on the coasts.
In the Pacific, the species are associated with the arribada. This is the mass nesting of ridley turtles.
The arribadas occur in Mexico, Costa Rica, Nicaragua, and Panama. In Mexico, the arribada occurs in Morro Aydfa and Playa Escobilla in Oaxaca, and Ixtapilla in Michoacan.
In Costa Rica, the arribada occurs at Ostional Beach and Nancite Beach. In Nicaragua, the arribada occurs in La Flor and Chacocente.
The BhitarKanika Wildlife Sanctuary is the largest nesting ground for the olive ridley. Large numbers are known to nest in Japan.
Hawksbill Sea Turtles
Red circles represent known major nesting sites. Yellow circles are minor nesting sites.
The hawksbill turtle is so called because of the shape of the head which resembles that of a hawk’s bill. This resemblance is easy to notice once you see these turtles.
The hawksbill is quite large when compared to other sea turtles such as the ridley turtles. The hawksbill has an average length of about 34 inches and a weight of about 176 lb or 80 kg.
As you can tell the species is much larger than most turtles. Turtles such as the leatherback and the loggerhead are much larger than the hawksbill.
The species can be found in the Atlantic, Indian, and Pacific Oceans. The subpopulations of this species can be divided into the indo-pacific and the Atlantic subpopulations.
In the Atlantic, the species are known to lay eggs in Costa Rica, Guadeloupe, Barbados, and the Lesser Antilles. All of these locations can be found in the Caribbean and the main nesting beaches.
The species lay eggs in other locations but these are the main nesting locations. In costa Rica, the species nest in Tortuguero. In Mexico, a popular nesting location is Yucatan.
What about the Indo-Pacific subpopulations? Where do these turtles nest?
Many nesting locations for the hawksbill can be found in Davao Oriental, Mati City – in particular Dahican Beach, Davao City – in particular Punta Dumalag, and Boracay island. These turtles also lay large numbers of eggs in the Turtle Islands in the Philippines.
Green Turtle Sea Turtles
The green turtle isn’t green in color. This species gets its common name from the color of its subdermal fat which is green.
The green turtle is also known as the black turtle – as it is black as hatchlings, the black sea turtle, and the green sea turtle.
According to IUCN, the species is known to lay eggs in more than 80 different countries. Of course, many of these nesting activities are solitary. Unlike the ridley, the green turtle doesn’t participate in mass nesting known as the arribada.
In the Atlantic, the main nesting sites are located in the Caribbean, the eastern shoreline of South America, the shore of North Atlantic islands, and the Atlantic coast of Florida.
In the Caribbean, they nest in Costa Rica – in places such as Tortuguero (which hosts most of the nesting population in the Caribbean), the Dominican Republic, Puerto Rico, the U.S. Virgin Islands, and Aves Island. Nesting females also visit the Cayman Islands regularly to lay eggs.
On the North American continent, the largest nesting site is the eastern coast of Florida in places such as Hutchinson Island. As many as 37,000 nesting females came to lay eggs in Florida in 2015. The species also visit South Carolina, North Carolina, and Georgia to lay eggs.
In South America, some major nesting sites include the Island of Ascension where 6,000 to 13,000 nests are laid each year, French Guiana, and Suriname.
In the Pacific, the species nest in several places. The major nesting locations include the northern shoreline of Australia, the south pacific islands, the Hawaiian Islands, and Mexico.
In the Indian Ocean, the species are known to nest in Sri Lanka, Pakistan, and India. They also nest on the African continent although nesting sites are limited. They are also known to nest in the islands around Madagascar.
In the Philippines, the species nest in considerable numbers on the Turtle Islands. In Indonesia, the green turtle is known to nest in the Meru Betiri National Reserve found in East Java.
In northern Australia, the species nest in the Great Barrier Reef. sites within the Great Barrier Reef include Raine Island, Bramble Cay, Coral Sea, and about 17 other locations.
The shores of the Arabian Sea in Karachi, Pakistan, and Ash Sharqiyah, Oman are important nesting locations. The green turtle also nests on the Galapagos Islands.
Flatback Sea Turtles
The flatback is endemic to the Australian continent shelf. This turtle is limited to just this location. As such the nesting locations of this turtle are limited to Australia.
The flatback is so-called because of its flat domed carapace. The sides of the carapace are upturned. This turtle is olive green in color. The plastron of this turtle is light in color.
The flatback is known to lay eggs only on the Australian continent. Nesting sites are scatted around northern to western Australia. The highest number of nesting sites is in Queensland – specifically on the soles of the Gulf of Carpentaria.
Nesting sites can be found on Curtis Island, Wild Duck, and the southern Great Barrier Reef. these nesting habitats can be found from Bundaberg to Torres Strait within Queensland.
As mentioned previously, the flatback also nests in Western Australia. Here significant nesting habitats include Lacrosse Island, Cape Dommett, and the Kimberley Region.
Leatherback Sea Turtles
The leatherback is the largest turtle and likely the largest living reptile. They are also considered to be the largest non-crocodilian reptiles.
These giants are also the fastest non-avian reptiles (all reptiles except birds) and a leatherback has been clocked moving at a speed of 21.92 mph (35.28 km/h) as reported by the Guinness Book of World Records in 1992.
The leatherback is so called because instead of a hard shell, the turtle has a tough leathery shell instead.
The species lay eggs on subtropical and tropical beaches. Some of their significant nesting habitats include the Mayumba National Park in Gabon, which hosts the largest nesting population in Africa with as many as 30,000 nesting females visiting from October to April.
Leatherbacks also nest on Florida’s eastern coast and in Costa Rica, particularly in the Parismina and Gandoca.
The species also nest on the beaches of the Solomon Islands, Indonesia, and Papua. Other nesting habitats in the Pacific include Washington, Oregon, and California.
The leatherback also nests on the pacific coast of Costa Rica, El Salvador, Panama, Mexico, Nicaragua, and eastern Australia. In 2008, two leatherbacks laid eggs at Rantau Abang in Terengganu, Malaysia.
Frequently Asked Questions
How to spot a sea turtle nest?
Turtle nests are well hidden and unless you are an expert, it can be difficult to spot a sea turtle nest. The best way to spot a sea turtle nest is to look for signs that a turtle has been there.
You can look for tracks and trails on the beach where the turtle lays the eggs. The tracks are made by flippers and you will notice long lines which show the species’ movement. If you see these trails, then it is likely a turtle nest is close by.
Another way to identify a sea turtle nest is by watching the beaches during the nesting season. If you are around when the sea turtle nests, you will know where that nest is.
How many eggs do sea turtles lay?
Sea turtles can lay a large number of eggs. It is essential that the turtle lay a large number of eggs as most of the eggs never make it to adulthood.
The average number of eggs a sea turtle can lay is 110 at a go. This makes a single nest. Turtles typically lay 2 to 8 nests every nesting season.
The flatback lays the smallest number of eggs. These reptiles lay about just 50 eggs per nest.
The hawksbill can lay over 200 eggs per clutch/nest although the average for the hawksbill is 140 eggs. Females lay about three clutches every nesting season.
The green turtle lays an average of 136 eggs per clutch or nest and as many as 200 eggs. The leatherback lays about 105 eggs per nest and about 5 to 7 nests per nesting season.
The loggerhead turtle lays about 15 eggs per nest. The olive ridley and Kemp’s ridley lay 107 eggs per nest on average.
Can sea turtles lay eggs underwater?
Sea turtles can only successfully nest on a sandy beach. If the egg is covered with water, the embryo won’t be able to breathe air and as such will die.
Turtles only nest on sandy beaches. If a turtle is unable to lay eggs on the beach, she may deposit the eggs in water. These eggs are unable to successfully hatch.
It is unlikely for a sea turtle to lay eggs underwater. This may happen if the turtle is disturbed while laying.
When disturbed during the nesting process, the turtle will retreat to the ocean and attempt to nest on the beach at another time, if she is unable to, she may deposit the eggs into the sea.
Where do turtles lay their eggs?
Turtles lay their eggs on sandy beaches. These are the only places the sea turtle can successfully lay their eggs.
Turtles interestingly return to the beach where they hatched as juveniles. The smell of the beach and other characteristics of the beach is imprinted in their memory.
This allows them to locate their natal beaches even decades later. Most nesting turtles lay eggs on their natal beaches.
How long do sea turtles live?
Sea turtles are long-living reptiles. The lifespans of turtles vary from one species to another.
Also, there is little information on the lifespans of sea turtles as they are quite difficult to study due to their migratory nature. Most sea turtle species are capable to travel thousands of miles every year.
The Kemp’s ridley, olive ridley, and hawksbill have a lifespan of 30 to 50 years. The green turtle has an average lifespan of 75 years.
The flatback has a lifespan of 100 years. The loggerhead has a lifespan of 62 years.
The leatherback has a lifespan of 30 to 50 years.
Why do sea turtles come ashore?
Once they hatch and rush to the sea, turtles never return to shore unless they nest.
With this only nesting females come to shore. Dead sea turtles can wash ashore.
Sea turtles, also known as marine turtles, lay eggs on beaches and lower dunes.
Beaches where turtles nest can be found all over the world. Places such as Oaxaca, Florida, and Texas have many beaches where sea turtles such as the Kemp’s ridley lay their eggs.
The BhitarKanika Wildlife Sanctuary is the largest nesting ground for the olive ridley. Large numbers are known to nest in Japan.
There are countless nesting habitats all over the world. While some of these sites are well-documented, most aren’t.
Regardless of this, most of the places where sea turtles nest are within the subtropics and the tropics.