Altruism

Tree frogs have been caught-out helping one-another find a strategic look-out post.

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(Nicolas Reusens / Caters News)

This unusual example of altruism adds just one more species to the very long list of those benefiting from a comrade’s kindness. Experimental proof that this altruism is a biological character, inherited by one generation after another, was famously worked out in the 1960s by an eccentric Oxford genius , Bill Hamilton. It is that relatives are worth helping in direct proportion to their blood-relatedness. The idea was taken up by Hamilton’s colleague Richard Dawkins in The Selfish Gene.

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C Monet Woman with Parasol (paintings galleries.blogspot.co.uk)

Tree frogs live in trees or other high-growing vegetation and descend to the ground to mate and spawn. They build foam nests on leaves and rarely leave the trees at all as adults. They easily change their colour for better camouflage. For example, the grey tree frog (Hyla versicolor) is usually green and changes to grey. Most adults are up to 5cms in length and have well-developed discs at the finger and toe tips; the fingers and toes themselves, as well as the limbs, tend to be rather long, resulting in a superior grasping ability. The genus Chiromantis has a particularly strong grip.

As a result of the relatives’ generosity, tree frogs and humans can find a good life. It also looks as though the photographer Alberto Ghizzi has shown that damselflies might do it as well.

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(Panizza/Solent News)

There are four major Families of tree frogs:

Hylidae occur in the temperate-  tropical parts of Eurasia, north of the himalayas, Australia and the Ameicas.

Rhacophoridae, or shrub frogs, are from tropical regions around the Indian Ocean, Africa and South Asia.

Centrolenidae, or glass frogs, are translucent and are native to Central and South America.

Hyperoliidae or reed frogs, are closely related to the Hylidae and are native to sub-Saharan Africa.

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