Sea turtles use Earth's magnetic field to navigate back to the same beach where they hatched after travelling thousands of miles, confirm scientists

Loggerhead sea turtles use the magnetic field of the Earth to navigate
Using this ability they make their way back to the beach where they hatched
Turtles make this annual trip to reproduce and lay eggs on the same beach
Magnetic fields are strongest predictor of genetic similarity among creatures

By Colin Fernandez Environment Correspondent For The Daily Mail

Published: 12:35 EDT, 12 April 2018 | Updated: 14:12 EDT, 12 April 2018

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Turtles return to the same place every year to lay their eggs by sensing the specific magnetic field of the beach where they were born, research has found.

Each beach has a distinct magnetic pattern which becomes imprinted on a turtle's brain to help them find their way back.

The findings explain how loggerhead turtles find their way back to their home nesting spot after travelling hundreds of miles out to sea.

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Turtles return to the same place every year to lay their eggs by sensing the individual magnetic field of the beach where they were born. Each beach has a distinct magnetic pattern which becomes imprinted on a turtle's brain to help them find their way back (stock)

Scientists from the University of North Carolina at Chapel Hill studied loggerhead turtle colonies in Florida.

They found that the marine reptiles are able to sense their 'home' beach on the Florida peninsula to lay their eggs by detecting how far north or south their beach is.

They do this by looking at the relation of the strength of the Earth's magnetic field in relation to any particular beach.

But the incredible super-power to sense the beach and its relationship to the Earth's magnetic field is not foolproof, researchers said.

Scientists found that turtles from one of the Floridian beaches were genetically more closely related to turtles hundreds of miles away, compared with animals a mere mile or two north or south.

To explain this finding, the researchers said the explanation must be that loggerhead turtles have laid their eggs on a beach that has a similar magnetic pattern.

The researchers said that 'magnetic fields are the strongest predictor of genetic similarity among nesting loggerhead sea turtles, regardless of the geographic proximity or environmental traits of nesting beaches.'

Kenneth Lohmann, professor of biology at UNC Chapel Hill said: 'Loggerhead sea turtles are fascinating creatures that begin their lives by migrating alone across the Atlantic Ocean and back.

The incredible super-power to sense the beach and its relationship to the Earth's magnetic field is not foolproof. Some turtles were more closely related to a distant population than their local neighbours. Indicating some distant beaches have similar magnetic patterns (stock)

'Eventually they return to nest on the beach where they hatched - or else, as it turns out, on a beach with a very similar magnetic field,' he said.

'This is an important new insight into how sea turtles navigate during their long-distance migrations.

'It might have important applications for the conservation of sea turtles, as well as other migratory animals such as salmon, sharks and certain birds.'

The authors of the paper, published in Current Biology, warn that their findings also suggest humans need to be careful with building anything on a beach that might confuse a turtle's magnetic sense.

Structures such as power lines, sea walls and large beachfront buildings could disrupt the magnetic field.

The findings may also have implications for other animals that sense the earth's magnetic field to navigate.

HOW DO ANIMALS USE EARTH'S MAGNETIC FIELD TO NAVIGATE?

Some animal species migrate around the world and travel vast distances.

With some animals doing it every year, some several times a year and some only once in their lifetime to the same place they were first born or hatched.

A Bar-Tailed Godwit, for example, is a small bird which is only 15 to 16 inches long (37 to 41 cm) and every year migrates from Alaska to New Zealand.

What is even more remarkable about this journey, is the fact that this bird does so without stopping.

The journey is more than 7,000 miles (11,500 km) and the bird does snot stop once for food or water, relying only on its fat reserves.

These birds are also incapable of soaring, meaning they have to flap their wings the entire time.

Some birds, such as stalks, can soar for long periods of time, relying on warm air currents to stay aloft.

These birds have also been shown to take fleeting naps of mere seconds whilst soaring on their journeys.

As to how they traverse such vast expanses, remains somewhat of a mystery.

For years, experts have believed that birds use visual signs or the sun to navigate.

Others speculated that a special organ in their beak allowed them to detect magnetic signals from the Earth.

Marine animals such as some whales and sea-turtles also cover huge distances before returning to a specific point.

Theories ranged from sonar to magnetic field detection yet again but conclusive proof has remained elusive.

The latest research has found, conclusively, that loggerhead sea-turtles do use the magnetic field of the Earth to navigate back to the same beach where they were hatched to reproduce.