Editing Winter (section)

==Ecological reckoning and activity==
[[File:Snowshoe hare.jpg|thumb|upright|The [[snowshoe hare]], and some other animals, change color in winter.]]
Ecological reckoning of winter differs from calendar-based by avoiding the use of fixed dates.  It is one of six seasons recognized by most ecologists who customarily use the term ''hibernal'' for this period of the year (the other ecological seasons being prevernal, vernal, estival, serotinal, and autumnal).<ref>{{cite web | author = Michael Allaby | title = A Dictionary of Zoology | year = 1999 | url = http://www.encyclopedia.com/doc/1O8-prevernal.html | access-date = 30 May 2012 | url-status = live | archive-url = https://web.archive.org/web/20130602225322/http://www.encyclopedia.com/doc/1O8-prevernal.html | archive-date = 2 June 2013 | df = dmy-all }}</ref>  The hibernal season coincides with the main period of biological dormancy each year whose dates vary according to local and regional climates in temperate zones of the Earth.  The appearance of flowering plants like the crocus can mark the change from ecological winter to the prevernal season as early as late January in mild temperate climates.

To survive the harshness of winter, many animals have developed different behavioral and morphological adaptations for [[overwintering]]:
*[[Bird migration|Migration]] is a common effect of winter upon animals such as [[migratory birds]]. Some [[butterfly|butterflies]] also migrate seasonally.
*[[Hibernation]] is a state of reduced [[metabolism|metabolic activity]] during the winter. Some animals "sleep" during winter and only come out when the warm weather returns; e.g., [[Gopher (animal)|gopher]]s, frogs, snakes, and bats.
*Some animals store food for the winter and live on it instead of hibernating completely. This is the case for [[squirrel]]s, [[beaver]]s, [[skunk]]s, [[badger]]s, and [[raccoon]]s.
*Resistance is observed when an animal endures winter but changes in ways such as color and musculature. The color of the fur or plumage changes to white (in order to be confused with snow) and thus retains its [[cryptic (zoology)|cryptic]] coloration year-round. Examples are the [[rock ptarmigan]], [[Arctic fox]], [[weasel]], [[hare|white-tailed jackrabbit]], and [[mountain hare]].
*Some fur-coated mammals grow a heavier coat during the winter; this improves the heat-retention qualities of the fur. The coat is then shed following the winter season to allow better cooling. The heavier coat in winter made it a favorite season for [[Animal trapping|trapper]]s, who sought more profitable skins.
*Snow also affects the ways animals behave; many take advantage of the insulating properties of snow by burrowing in it. Mice and [[vole]]s typically live under the snow layer.

Some [[annual plant]]s never survive the winter. Other annual plants require winter cold to complete their life cycle; this is known as [[vernalization]]. As for [[perennial plant|perennial]]s, many small ones profit from the insulating effects of snow by being buried in it. Larger plants, particularly [[deciduous|deciduous trees]], usually let their upper part go dormant, but their roots are still protected by the snow layer. Few plants bloom in the winter, one exception being the [[prunus mume|flowering plum]], which flowers in time for [[Chinese New Year]]. The process by which plants become acclimated to cold weather is called [[Hardening (botany)|hardening]].