Ptarmigan change their plumage from a summertime brown to a wintery white once the season sets in.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/38623372@N06">Bering Land Bridge National Preserve</a>
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/bering_land_bridge/9514353680/">Ptarmigan Flock</a>