17.01.2012

Colour blind people "may have an advantage"

Colour blind people "may have an advantage"

By Adrian Galbreth

People who are colour blind may have an advantage over those who have supposedly 'normal' vision by being able to spot things that others cannot, a new study has suggested.

According to research carried out at Anglia Ruskin University, colour blind monkeys are better at catching camouflaged prey than monkeys with "normal" eyesight – something which may also apply to humans, given the closeness of their DNA to that of simians.

The study was led by Dr Andrew Smith, from Anglia Ruskin's Department of Life Sciences, and also involved scientists from the University of Stirling, the University of Cambridge and the University of Sussex, with the results published in the journal Animal Behaviour.

In the report, the experts detail how they studied three species of tamarin monkey - saddleback, moustached and red bellied - in the Amazon rainforest in Peru and in captivity at Belfast Zoo, and found that levels of colour vision affects the rate and type of insect capture.

The tamarins with normal colour vision, known as trichromats, caught more prey than colour blind tamarins, known as dichromats, but the colour blind tamarins were significantly better at catching camouflaged insects, such as crickets.

Dr Smith explained that colour blindness clearly has several possible advantages for the tamarins.

"There is evidence in humans that dichromats see better in dim light than trichromats, it is thought that dichromats may have improved spatial vision and, crucially, dichromats appear to be superior at visually breaking camouflage," he elaborated.

The expert said experiments have shown that colour blind humans and non-human primates are better able to detect targets based on texture or outline, while for colour normal humans and primates the target is camouflaged by colour.

Dr Smith stated: "This means that colour blind wild primates actually have an advantage in their natural habitat when it comes to detecting both camouflaged prey and predators."

by Martin Burns


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