Why do rabbits often have white hindquarters? There are several species of herbivores that have a very visible white hindquarters: several kinds of deer, rabbits, antelopes, etc. Does the white fur serve a functional purpose, or is it purely random? Is it defensive enabling them to escape predators, or is it for intraspecies communication? Examples photos to clarify: ![Rabbit]( deer Notice that otherwise relatively well camouflaged animals have visible white fur.

Apparently the most noticeable research on this subject of a rabbit's white behind has been done by Dr Dirk Semmann of the University of Goettingen. He proposes that

> these spots actually confuse predators because of their very noticeable nature. By focusing on the bright spot, the would-be predator ignores the larger body of the animal. Then, when the rabbit executes a sharp turn, the spot disappears and the predator has to readjust to focus on the camouflaged coat, losing vital seconds (reference 1, reference 2).

It could be the same reason for the white behind of a deer. As to why deer flag their tails, there is a paper on the subject which lists 4 possible reasons for the behaviour.

1) Flash behaviour

2) Alarm Signal

3) Cohesive signal

4) Detection signal

More can be read about it in this paper.