Some prey animals, like rabbits and deer, feature flashy white tails that are prominently displayed when they're been chased down by predators. But why in the world would an animal want to draw more attention to itself in such a precarious situation? We now have the answer.


According to evolutionary biologist Dirk Semmann of the University of Goettingen in Germany, it's not a component of sexual selection (i.e., like a peacock's attractive tail), nor is it a sign to a predator that it has been spotted.

Rather, it's a way to confuse predators during the chase.


White tailed jack rabbit. Credit: Grey Lasley Nature Photography.

Because these white tails are very noticeable, predators focus on these bright spots — but at the expense of focusing on the larger animal. When a rabbit or deer executes an evasive maneuver, like a sharp turn, the spot suddenly disappears, causing the predator to readjust its focus on the camouflaged coat. This will cost it some vital time, giving the prey animal those precious added seconds to escape.

And fascinatingly, Semmann tested his theory by having 24 humans play a video game in which they attempted to follow a virtual rabbit both with and without a flashing tail. As suspected, the presence of a tail significantly reduced their number of correct moves.

Semmann recently presented this evidence in Newcastle at the Behaviour 2013 conference.


[Source: Nature News Blog]

Image: Hare Coursing: MSNBC.