( CNN ) -- They barely slept . That 's the case for an unusual number of black bears in western Nevada , where an abnormally warm and dry winter has spurred them to halt their hibernation and head out for food . `` They may be sleeping under a deck or under a house in a crawlspace , and they will emerge when it is a garbage day and raid some garbage cans and then go back to a sleep for a while , '' explains Chris Healy , a spokesman for the Nevada Department of Wildlife . Mother Nature can take credit for these bears ' abbreviated slumber . Whereas parts of the Midwest and Northeast are now buried in snow and shivering in cold , that 's not the case in many communities around Lake Tahoe and elsewhere . The National Weather Service 's forecast for Incline Village , Nevada , for instance , calls for high temperatures heading to or well past 50 degrees for the next week at least , with nary of snow flurry in sight . What 's with this weather ? Hot is cold and cold is hot . It 's not just Nevada : Nearby Northern California is also seeing an abnormal number of black bears , with CNN affiliate KXTV showing images taken from Yosemite National Park and Lake Tahoe 's Heavenly Ski Resort . Healy said `` a disastrous winter '' -- adding `` we need the snow '' -- and relatively mild temperatures have thrown off some black bears that live in more settled areas , where they can readily access human garbage . `` We documented this and , in the past 15 years , it occurs sporadically , '' the spokesman said . `` A lot of it is dictated by the weather conditions . '' Even in a typical winter , black bears do n't hibernate completely as some might think , usually taking a few weeks for their metabolism and body temperature to wind down . They will occasionally wake up , roam a bit , but wo n't eat , drink , urinate or defecate , according to SierraWild.gov , a cooperative website of the federal U.S. Forest Service , National Park Service and Bureau of Land Management that covers the Sierra Nevada mountain range , including Lake Tahoe ) . Bears in this range typically `` den '' between mid-December into March or the beginning of April , SierraWild.gov notes . This is less than the seven and a half months for some black bears that live in colder climes , but still well beyond what 's being seen in parts of Nevada . In the past , `` lighter winters '' have been correlated to `` bigger bears that live among humans in Incline Village in the Lake Tahoe basin , '' notes Healy . But it 's not like every black bear is cutting short hibernation and heading out on the town . Healy notes , `` Bears in the backcountry -- truly wild bears -- do n't partake in this . '' `` They eat nuts and berries and things that are not found in nature right now , '' he said , in contrast to the relatively ever-present trash rummaged through by other bears . `` So they would n't wake up to eat , they would n't find anything . '' It has also been `` unusually warm '' this winter in much of Alaska . But state wildlife official Riley Woodford said that bears coming out of hibernation early has n't been an issue there yet . That 's because the winter started off , around November , normally . Even though it 's warmed up , the bears climbed up to 1,000 feet to den in snowy and icy spots that 's cold enough to keep them in , he says . Still , the state Department of Fish and Game admits that , hibernating or not , the weather has been weird . It 's not even forecast to go below freezing -- even at night -- in Juneau for at least a week . And last week , it was even raining 3,000 feet above sea level in one ski resort around the Alaskan capital , Woodford recalls . Historic California drought forces rancher to thin herd of horses . CNN 's Dave Alsup contributed to this report .
Black bears in the Sierra Nevadas typically `` den '' from December through early spring . But some emerge from hibernation early in what 's been called a `` disastrous winter '' Such bears live near places they can root through garbage ; `` wild bears '' are n't affected yet . Official : It 's also been unusually warm in Alaska , but bears there so far have stayed put .