Guide

Happening unseenMammals

Black bears in their winter dens in Massachusetts

January to February

Massachusetts black bears spend the coldest months in winter dens, and they are not considered deep hibernators. In mid-to-late January, mother bears give birth to cubs inside the den.

Why this time of year

MassWildlife says bears den between mid-November and early December and leave between early March and mid-April, so January and February sit inside the denning season, and cubs are born in the den in mid-to-late January. Bears live and breed in Worcester County, northern Middlesex County, and west to the Berkshires; MassWildlife says the bears that turn up east of Route 495 are often dispersing young bears and wandering males.

How to notice it

  1. Picture where a bear might be resting: MassWildlife lists brush piles, the space under fallen trees, jumbles of rocks, and mountain laurel thickets. Enjoy the idea from a distance - this card is not a reason to go looking for a den.
  2. Feel your own heartbeat for a minute. Mass Audubon says a denned bear's heart slows from 40-50 beats a minute to 8. Its body cools only to about 88 degrees, from 100 in summer, which is why bears are not considered deep hibernators.
  3. Where bears live, check the yard for bear food. MassWildlife says to take bird feeders down at the first sign of bear activity and not to leave empty feeders out.
  4. If a bear turns up in your yard on a mild day, MassWildlife says to wait for it to leave and then put away any food. Mass Audubon notes that in a mild winter bears could stay active.

Try this with kids: Put two fingers on your neck and count your heartbeats for one minute. A sleeping bear's heart beats only about 8 times in that minute. How many did you count?

Phrase to know: “Deep hibernator”: an animal whose body temperature drops far down in winter, like a woodchuck's falling to an average of 40 degrees; a bear's drops only to about 88.

Safety

  • If you meet a bear, MassWildlife says to talk calmly, back away slowly, never run, never approach, never get between a mother and her cubs, and keep dogs on a leash.

Sources

  • web.archive.orgMassWildlife, Internet Archive snapshot 2026-05-28 (live page 403). 'Depending on food availability and snow cover, bears will den between mid-November and early December and exit between early March and mid-April.' 'Bears commonly den in brush piles, under fallen trees or jumbles of rocks, or in mountain laurel thickets.' 'A litter of usually two or three cubs is born in the den in mid-to-late January.' 'Black bears live and breed in Worcester County, northern Middlesex County, and west to the Berkshires.' 'Dispersing young bears and wandering males often find themselves east of Route 495.' 'estimated to be over 4,500 animals and is growing and expanding eastward.' 'There is no safe time of day or year to have bird feeders out.' 'talk in a calm voice and slowly back away. Do not approach bears or intrude between a female bear and her cubs. Do not run.' 'You should remove bird feeders at the first sign of bear activity and avoid leaving empty feeders out.' 'If you see a bear in your yard, wait for the bear to leave, then remove or secure food sources on your property.' 'Keep dogs leashed whenever they’re outside and never let dogs chase or interact with bears.' (these three re-read by the lead 2026-11-10)
  • massaudubon.orgMass Audubon species page. 'Black bears are not considered "deep" hibernators. When bears enter the den, usually between early November and mid-December.' Body temperature 'drops very slowly to about 88 degrees, only a slight change from its summer temperature of 100 degrees.' Heart rate 'drops from 40 to 50 beats per minute to 8 beats per minute.' 'den in caves, brush piles, depressions under fallen trees, or rock crevices.' Emergence 'determined by the availability of food, rather than weather conditions, and usually takes place in April.' Feeders 'only from mid-December to the end of February, when bears are typically denned' and 'If it is a mild winter, bears could remain active year-round.'
  • massaudubon.orgMass Audubon Outdoor Almanac, January 2024 (dated PDF). January 29: 'Black bears are giving birth to litters of 1-5 cubs.' and 'Black bears are sleepers, not hibernators, and might be seen out of their dens during milder weather.'

Checked against these sources on November 10, 2026.

In the guide for January, February

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