  Reproduced with permission of the Minister of Public Works &
Government Services Canada, 2001  Animal Color Change  ­ ­In the
last section, we saw that the most basic form of camouflage is a
coloration that matches an animal's surroundings. Of course, an
animal's surroundings may change from time to time. Many animals
have developed special adaptations that let them change their
coloration as their surroundings change.  One of the biggest
shifts in an animal's surroundings occurs with the changing of
the seasons. In the spring and summer, a mammal's habitat might
be full of greens and browns, while in the fall and winter,
everything can be covered with snow. While brown coloration is
perfect for a summer wooded environment, it makes an animal an
easy target against a white background. Many birds and mammals
deal with this by producing different colors of fur or feathers
depending on the time of year. In most cases, either changing
amounts of daylight or shifts in temperature trigger a hormonal
reaction in t