CHAMELEONS tailor their camouflage to a predators' eyesight, taking it easy when their attacker has poor colour vision.
Devi Stuart-Fox at the University of Melbourne, Australia, and colleagues placed Smith's dwarf chameleons on branches alongside lifelike models of two animals which prey on them: the fiscal shrike - a bird that impales chameleons on a thorn before eating them - and the boomslang, a tree snake.
They found that the chameleons colour-matched their backgrounds more closely when presented with the bird than the snake. However, when the team took into account the visual acuity of both predators, they found that the chameleon would appear better camouflaged to the snake, whose colour vision is poor, than the bird. Faced with a snake, it seems, the chameleons just don't have to try as hard (Biology Letters, DOI: 10.1098/rsbl.2008.0173).
The researchers also noticed that chameleons faced with the tree snake were ...
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