Thursday, April 07, 2016

Tartarugas voltam a casa, apesar da distância !






credits: Dr Takahiro Shimada/JCU

Um estudo publicado no dia 31 Março na na Austrália revelava que as tartarugas são capazes de nadar mais de cem quilómetros depois de terem permanecido em cativeiro durante mais de um ano, com o objectivo de 'voltar a casa'.
“Perdemos contacto com os aparelhos de rastreio colocados em duas delas, mas à excepção de uma, todas regressaram a casa.”

Takashiro Shimada, biólogo, autor estudo

O biólogo marinho da Universidade James Cook e autor do estudo seguiu 59 tartarugas.




Dr. Takashiro Shimada, cientista
credits: Dr Takahiro Shimada/JCU
A investigação revelou que a maioria das tartarugas que passaram algum tempo em cativeiro – curtos períodos ou mais de 500 dias sob cuidados, devido a lesões – encontrou o caminho de regresso ao local onde haviam sido encontradas, segundo um comunicado da Universidade James Cook.
Além das longas distâncias percorridas – uma nadou 117 quilómetros –, os cientistas observaram que as tartarugas nadaram até poucos metros do ponto em que foram encontradas.
Os investigadores acreditam que as tartarugas nadam, tendo como orientação uma combinação de 'chaves geomagnéticas' e outros processos que ainda não são completamente compreendidos.



credits: Dr Takahiro Shimada/JCU
Os cientistas também colocaram 54 tartarugas directamente no ponto em que foram encontradas, para depois testar se permaneciam nesse lugar, apesar de não terem conseguido decifrar as causas na origem desse padrão, refere a mesma nota.
“O senso comum sugere que tal sucede porque as tartarugas estão familiarizadas com as fontes de comida e albergue e sabem onde podem estar os seus predadores.”

Takashiro Shimada


credits: Dr Takahiro Shimada/JCU)
While it has long been known female marine turtles return to their birthplace to nest, Queensland researchers have recently discovered the whole family of turtles is able to find its way home after being displaced.
A James Cook University study has found turtles released back into the wild almost always return home – even if they have to swim more than 100km or have spent more than a year away.

Lead author, Dr Takahiro Shimada said the JCU team tracked 59 turtles released outside of the areas where they had been found along the Queensland coast.

“We lost communication with the tracking devices on two of them, but all except one of the rest returned home,” he said.


Dr Takahiro Shimada/JCU)
credits: James Cook University
While most of the turtles travelled to their old homes after a short time in captivity, one of the returning turtles had been held for more than 500 days while it recovered from injury. Another was released more than 117 km from where it was originally found and successfully made the journey back.

“It was surprising, we weren’t quite sure if they would make it back over that distance or after that amount of time.” 

Dr Shimada


credits: Dr Takahiro Shimada/JCU

He said researchers were also surprised with the precision of the turtles’ navigation – with most eventually ending up within a few hundred metres of their home. 
(...)

The scientists say the finding has important implications for turtle conservation, with long-term resettlement of turtles away from dangerous or damaged environments not a realistic option. Read more here 

Geração 'green'

07.04.2016

Creative Commons License

References:

Credits All the photographies  are of Dr Takahiro Shimada / JCU scientist.

fonte: Observador | Ciência

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