Scientists solve mystery of why Amazonian manatees migrate

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London, December 25 (ANI): In a new research, scientists have determined that the Amazonian manatee migrate from shallow to deep water to avoid being exposed to attack by predators during the low-water season.

That means the species may be at greater risk than thought, as migration and low water levels make them vulnerable to hunters.

According to a report by BBC News, the scientists, from Brazil and the UK, took into account the elusive Amazonian manatee, which is a large plant-eating mammal that lives in freshwater.

Due to its peculiar shape, it has been described as a cross between a seal and a hippo.

The species is only found in the Amazon River basin from the river mouth to the upper reaches of tributaries of Brazil, Colombia, Ecuador, Guyana, and Peru.

Every year, they are probably migrating through narrow channels where they are exposed to hunters.

The researchers studied manatees that live within the Mamiraua and Amana Sustainable Development Reserves in the north west of Brazil.

To obtain their results, the researchers asked local inhabitants about the animals' movements, studied the shapes and depths of the local rivers and lakes and then used radio tracking tags to follow the movements of 10 manatees.

During the high-water season, between mid May and the end of June, manatees live in quiet lakes called varzeas that form within river flood plains, the scientists found.

Here, the manatees consume 8 percent of their body weight in aquatic plants each day.

Then during the low-water season, between October and November, the animals start to migrate as the water level drops.

They journey to deeper water within long narrow lakes called rias, which are submerged river valleys.

They do this because it becomes too dangerous to remain in shallow water, according to the scientists.

If the manatees do not move, they become stranded and exposed to hunters such as caimans, jaguars and humans who stalk the water margins.

The perilous journey has a downside; in the sense it forces the manatees to fast for several months due to a lack of aquatic plants.

"Amazonian manatees migrate to a habitat that doesn't offer easy living conditions in order to flee from a habitat that becomes inhospitable," said Dr Eduardo Moraes Arraut from the National Institute for Space Research in Sao Paulo, Brazil who undertook the latest study.

According to explains Dr Arraut, "Manatees are in greater danger than previously thought because every year they are probably migrating through narrow channels where they are exposed to hunters." (ANI)

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