World's only iridescent mammal is a shiny accident

Animals from butterflies to birds have iridescent colours to draw the eye. But why golden moles? They spend most of their lives in near-darkness - and they're blind.

Now a study of the structure of the hairs shows that they may be designed to streamline the moles or repel water, rather than attract a mate.

Matthew Shawkey of the University of Akron in Ohio took samples from four golden mole species, all with blue or green iridescence. Electron microscopes revealed that the hairs were flattened into paddle shapes, giving a greater surface area to reflect light.

Unusually, the scales on each hair contained alternating light and dark layers. Each layer bent the rays of light just like oil on water (Biology Letters, DOI: 10.1098/rsbl.2011.1168). Shawkey says this is the first example of a multilayer reflector in hair.

The iridescence is an evolutionary accident, he believes. The hairs' structure may make them more sturdy, repel water, or streamline the moles so they can move quickly through dirt and sand. "Penguin feathers are flattened like this," he points out.

Most iridescent animals probably evolved it for communication, but golden moles are a rare exception, says St?phanie Doucet of the University of Windsor in Ontario, Canada. Some burrowing snakes and beetles are also iridescent, probably for similar reasons, she adds.

If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to.

Have your say

Only subscribers may leave comments on this article. Please log in.

Only personal subscribers may leave comments on this article

Subscribe now to comment.

All comments should respect the New Scientist House Rules. If you think a particular comment breaks these rules then please use the "Report" link in that comment to report it to us.

If you are having a technical problem posting a comment, please contact technical support.

Source: http://feeds.newscientist.com/c/749/f/10897/s/1c216d39/l/0L0Snewscientist0N0Carticle0Cdn21390A0Eworlds0Eonly0Eiridescent0Emammal0Eis0Ea0Eshiny0Eaccident0Bhtml0DDCMP0FOTC0Erss0Gnsref0Fonline0Enews/story01.htm

debra messing ayaan hirsi ali rachel uchitel strait of hormuz new years eve party ideas mars needs moms gary johnson