Verpeilte sea turtles: single-mindedly in the wrong direction

place Green sea turtles, their eggs, where they are even hatched. For this, they leave their feeding areas and often swim thousands of kilometres through the op

Verpeilte sea turtles: single-mindedly in the wrong direction

place Green sea turtles, their eggs, where they are even hatched. For this, they leave their feeding areas and often swim thousands of kilometres through the open sea to their accustomed nesting grounds and back again. You can draw, obviously, only a rough navigation system, and often have to search long before they found the right target. The cost of the animals, force and time, as studies by Graeme Hays of Deakin University in the Australian Geelong in the journal "Current Biology" show. However, sea mate turtles only every two to three years.

While a lot is known about how well animals short distances, masters, and little is known about how accurate in the open ocean to navigate. Hays and his colleagues have equipped 33 Green sea turtles with satellite transmitters and monitored, which of course you will take when they return from their nesting grounds on the Diego Garcia Atoll in the Western Indian ocean to their feeding grounds on the East coast of Africa and the offshore Islands. Some animals traveled more than 4000 kilometers and were weeks on the road, without food. The researchers also determined the deviations from the direct course, and were expecting the flow.

the earth's magnetic field provides orientation

The animals started their journey in the right direction, but not on a direct course. Often they were hundreds of miles of the mark and had to correct your Route on the open sea. Did you sometimes abruptly, after they had previously swum yet determinedly in the wrong direction. The animals use the magnetic field of the earth, but obviously only a rough map. Otherwise you would not have to readjust course constantly and not only when you deviate significantly from it. Also in the immediate vicinity of their food or nesting sites, the turtles searched for days and days after their seagrass ancestral pastures. So, even for short distances, a precise navigation system is missing.

The results are for the protection of these species is quite relevant. Green sea are the oldest living reptiles, and for around 225 million years on earth are turtles. Although their existence in the past few years, has recovered, are threatening the animals to extinction. Do you suffer from the colonization of the beaches, climate change, garbage in the sea, and the greed for turtle meat, and tortoiseshell. Many animals become entangled in boats also in the networks of fishing. The data of Hays and his colleagues make it clear that the protection facilities for fishing must be very much broader than in the past.

Updated Date: 31 August 2020, 21:20

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