Turtles migrate in search of favorable environmental conditions and food. They migrate toward the south in winter for warm waters and migrate toward the north in summer for food. Sea turtles mostly migrate from foraging to nesting grounds. Thus, turtles have a cyclical migration behavior.
There are a lot of things to learn when it comes to turtle migration. So, let’s delve deeper and understand their migration behavior and other things related to it.
Do Turtles Migrate Or Hibernate?
Most turtles hibernate. The further the turtles are from the equator, the sooner and longer they take a winter nap.
In contrast, the turtles that are close to the equator may not hibernate as the temperature is warm.
Just like other animals, turtles need a cooling period for the better functioning of their immune system.
So, in the winter, turtles find a safe place to hibernate.
Depending upon the species, turtles dig a deep and big hole to hibernate.
Some turtle species go to the pond’s bottom and find a protected spot to burrow themselves under the debris.
Unlike other turtle species, sea turtles don’t hibernate. Instead, they migrate to warmer tropical waters during winter.
Which Turtles Migrate?
All turtle species migrate for some reason or the other.
Some migrate for nesting purposes, while others migrate in search of food or to avoid enemies.
Some of the common turtle species that migrate include:
- Sea turtles like leatherbacks, loggerheads, flatbacks, Kemp’s Ridley sea turtles, etc.,
- Snapping turtles,
- Pond turtles, and
- Hawksbill turtles.
Why Do Turtles Migrate?
Most sea turtles migrate between foraging and nesting grounds.
Both the male and female sea turtles migrate to nesting areas for breeding purposes.
They migrate to the area where they were born to reproduce.
Loggerhead hatchlings are tiny and defenseless at birth.
Since they are tiny, newborn loggerheads can’t make deep dives and hence swim slowly along the ocean’s surface.
This makes them vulnerable to predators who make them their meals.
Hence, loggerhead hatchlings migrate from the danger-filled coastal zones to the open sea to avoid their enemies.
Once these hatchlings become adults, they migrate back to the coastal North American waters.
There are numerous sea turtle species, each of them has different developmental migration patterns.
For example, green sea turtles migrate to shallow grass beds as they prefer an herbivorous diet.
Once the turtles grow bigger, they sometimes even do daily migrations in search of food.
During the day, these turtles head toward shallow waters to feed.
Then, once night approaches, they head back to deeper waters to rest.
Snapping turtles travel extensively on land to lay eggs or to reach new habitats.
Some common reasons for snapping turtles to migrate include pollution, overcrowding, food scarcity, and habitat destruction.
On the other hand, pond turtles migrate on land to conserve their water.
They do this particularly during hot and dry days by slowing down their metabolism.
Leatherback sea turtles eat jellyfish in abundance.
So, they migrate thousands of miles each year between foraging grounds just in search of jellyfish.
How Do Turtles Migrate?
Animals generally migrate in search of favorable environmental conditions.
These conditions can include nesting opportunities or a habitat with ample food.
In the case of turtles, migratory behavior is cyclical.
Thus, migration may occur daily, seasonally, annually, or even for longer times, depending upon the reason.
As per research, changes in climate, environment, and photoperiod trigger the migratory behavior in sea turtles.
In addition, water currents play a role in assisting the turtles during migration.
Currents propel the sea turtles back toward the equatorial nesting sites during migration.
Sea turtles navigate through the waters by using the magnetic crystalline structures within their brains as an internal compass.
Earth’s magnetic field assists the functioning of this internal compass.
One promising theory on how sea turtles navigate suggests that they can detect the angle and intensity of the earth’s magnetic field.
Using these characteristics, sea turtles can determine the latitude and longitude, enabling them to navigate any place.
However, whether turtles actually use this ability for navigation is still not clear and is being investigated.
When Do Turtles Migrate?
Turtles migrate toward the north during the summer months in search of food.
The same turtles travel south during winter, where the water is relatively warmer.
Atlantic leatherback sea turtles migrate annually from foraging grounds of the northeastern United States and eastern Canada to southern breeding grounds.
Snapping turtles usually don’t leave their aquatic habitat except during the breeding season.
Female turtles migrate every few years once they become adults. Then, they migrate to the beach they were born to reproduce.
Where Do Turtles Migrate To?
Turtles’ migration varies not only by species but also by different populations of similar species.
For example, some sea turtles migrate great distances, whereas other sea turtle populations prefer the same general areas to feed and nest.
Given below are the different places where various turtles migrate to:
- Black sea turtles migrate between the northern and southern extremes of their distribution range. They usually migrate along the coast from breeding areas to feeding grounds.
- Populations of Olive Ridley sea turtles travel between feeding and nesting grounds in the Eastern Pacific and Indian oceans.
- Flatback turtles migrate from their nesting grounds on the northern coast of Australia and its islands to feeding grounds in the shallow waters of North-Eastern Australia.
- Kemp’s Ridley turtles are known to follow two major routes in the Gulf of Mexico. One route is from southward to the Campeche Bank, and the other route is northward to the Mississippi area.
- Green sea turtles primarily migrate along the coasts from the nesting to feeding grounds.
- Some sea turtle populations travel across the Atlantic Ocean from the Ascension Island nesting grounds to Brazilian coast feeding grounds.
- In the Atlantic Ocean, turtles migrate from the Caribbean beaches up toward the US east coast to Canada.
- Many turtles travel from Southeast Asia to California and further to Alaskan waters in the Pacific Ocean.
How Far Do Turtles Migrate?
The migratory behavior of turtles is fascinating. Many chelonian species migrate short distances.
In contrast, some others migrate long distances annually, crossing the world’s oceans.
Aquatic turtles migrate a long distance for nesting.
Sea turtles migrate thousands of miles through high seas and ocean basins in their lifetime.
Male and female sea turtles migrate long distances between foraging grounds and nesting beaches.
Leatherback sea turtles are one of the highly migratory animals.
They migrate around 10000 miles or more every year between foraging grounds in search of jellyfish.
In the Pacific, many leatherback turtles travel from Southeast Asia (Malaysia and Indonesia) to California and then travel up to Alaskan waters.
Whereas in the Atlantic, these turtles migrate from Caribbean beaches up the East coast to Canada.
Adult green sea turtles migrate every 2 to 5 years to reproduce.
They migrate from their coastal foraging areas to the nesting beaches where they originally hatched.
Green sea turtles migrate distances longer than 1600 miles with the assistance of their strong paddle-like flippers to propel through the water.
Solomon Island hawksbills travel between 500 to 1000 miles between nesting beaches and foraging areas of Australia.
In contrast, Hawaiian hawksbills migrate shorter distances and stay within the island chain itself.
Loggerhead turtles that are born in Japan migrate up to 8000 miles. They undertake a trans-Pacific migration.
Hatchlings born in Japan migrate across the Pacific to the coast of Baja California, Mexico, to feed and mature.
Once the hatchlings mature, they migrate back to Japan to breed and nest.
As per this news report, Yoshi, a female loggerhead sea turtle, set a record of swimming 22000 miles in two years of her migration journey from Australia to South Africa.
Related Questions
Do sea turtles migrate in groups?
Sea turtles are solitary creatures. They usually remain submerged underwater. Hence, it isn’t easy to study them.
Moreover, sea turtles rarely interact with one another, except during the courtship and mating period.
However, Olive Ridley sea turtles do travel in massive groups during nesting.
When do turtles migrate in Hawaii?
Honu or Green Hawaiian sea turtles make a round trip migration of around 1200 miles from their feeding areas in the main Hawaiian islands to French Frigate Shoals in the Northwestern Hawaiian Islands.
Female turtles are accompanied by male turtles during the migration and mate offshore from the nesting beaches.
After nesting, they swim back again to the Hawaiian Islands.
References
- https://www.conserveturtles.org/information-sea-turtles-general-behavior/
- https://blogs.scientificamerican.com/observations/how-a-painted-turtle-finds-its-way/
- https://www.turtlehospital.org/uncategorized/sea-turtle-migration/
- https://seaworld.org/animals/all-about/sea-turtles/habitat/
- https://www.worldwildlife.org/stories/how-long-do-sea-turtles-live-and-other-sea-turtle-facts
- https://europe.oceana.org/en/eu/media-reports/features/migration-of-sea-turtles
