Bird Sight

Here is an interesting article about bird navigation.
http://physicsworld.com/blog/2011/02/the_secret_navigational_powers.html
and http://physicsworld.com/cws/article/indepth/45059

This article explains the science more:

http://www.wired.com/wiredscience/2011/01/quantum-birds/

Thanks to Emma for these links.