← Back to the archive★ Support my pages
DD-681Naturealso ScienceFiled Last updated

Ursine Uptime

Short answer: 'Walking hibernation' is a real term. The North American Bear Center describes it as the 2-3 weeks after bears leave the den, when they move around but eat and drink less than normal while their bodies return to summer levels.

In a 2011 Science study, Øivind Tøien and colleagues continuously monitored black bears (Ursus americanus) in Alaska. They found the bears cut their metabolism to about 25% of the basal rate while body temperature fell only modestly, cycling between about 30 and 36 °C. Heart rate dropped from about 55 to as few as 9 beats per minute, and metabolism stayed reduced for up to three weeks after the bears emerged. Studies of brown bears in Sweden found body temperature normalized about 10 days after emergence, and heart rate took about a month. Black bears in closed dens go 5-7 months without eating, drinking, urinating or defecating, but mothers in open dens may lick meltwater and clean up after cubs.

VideoWrite-up4 sources
More like this★ Support my pagesCite this file

What should you know about Ursine Uptime?

Quick facts. Each one stands alone and has a stable ID you can cite.

  1. After leaving the den, bears stay in 'walking hibernation' for about 2-3 weeks.

    DD-681-F01 · Write-up · Exhibit A (Walking hibernation)

  2. Black bears cut metabolism to about 25% while lowering body temperature only about 5-6 °C.

    DD-681-F02 · Write-up · Exhibit B (Metabolism without the chill)

Video transcript: Ursine Uptime: Awake but Still Hibernating

DID YOU KNOW? When bears come out of hibernation in early spring, they enter a transition phase called "walking hibernation", where their metabolism is still slow, and they gradually regain full strength. During hibernation, a bear's heart rate, body temperature, and calorie use drop dramatically, allowing it to survive months without eating, drinking, or expelling waste. NOW YOU KNOW!

Burned-in captions, read frame by frame (see transcript.md) · 17.9s Reel ·

Video coming soonUrsine Uptime · Instagram Reel
Ursine Uptime: Awake but Still Hibernating Instagram Reel · · 17.9s

The write-up

Awake but still hibernating. Bears' metabolism stays low for weeks after they leave the den.

  1. Exhibit A

    Walking hibernation

    For about 2-3 weeks after leaving the den, bears are up and moving, but their metabolism is still adjusting. They voluntarily eat and drink less and excrete less than they will later in the year.

  2. Exhibit B

    Metabolism without the chill

    Tøien's black bears cut metabolism to about 25% of basal rates but lowered body temperature by only about 5-6 °C, cycling between about 30 and 36 °C in multi-day rhythms.

  3. Exhibit C

    A slow heart

    Heart rates fell from about 55 to as few as 9 beats per minute, with pronounced arrhythmia during breathing pauses.

  4. Exhibit D

    No food, water or waste

    Bears in closed dens go 5-7 months without eating, drinking, urinating or defecating. Mothers in open dens may eat snow and clean up after their cubs.

  5. Exhibit E

    The slow restart

    In brown bears studied in Sweden, body temperature normalized about 10 days after emergence and heart rate took about a month.

Questions people ask about Ursine Uptime

What is 'walking hibernation'?

About 2-3 weeks after emergence.

Source: Write-up · Exhibit A (Walking hibernation) · North American Bear Center: 5 stages of activity and hibernation; Tøien et al. (2011), Hibernation in black bears: independence of metabolic suppression from body temperature, Science (PubMed)

Black bears cut their metabolism to about what share of basal rates?

About 25%.

Source: Write-up · Exhibit B (Metabolism without the chill) · Tøien et al. (2011), Hibernation in black bears: independence of metabolic suppression from body temperature, Science (PubMed); EurekAlert! (2011): Bears uncouple temperature and metabolism for hibernation

About how much does a black bear's body temperature fall?

Only about 5-6 °C.

Source: Write-up · Exhibit B (Metabolism without the chill) · Tøien et al. (2011), Hibernation in black bears: independence of metabolic suppression from body temperature, Science (PubMed); EurekAlert! (2011): Bears uncouple temperature and metabolism for hibernation

How low can a hibernating black bear's heart rate go?

As few as 9 beats per minute.

Source: Write-up · Exhibit C (A slow heart) · Tøien et al. (2011), Hibernation in black bears: independence of metabolic suppression from body temperature, Science (PubMed); EurekAlert! (2011): Bears uncouple temperature and metabolism for hibernation

How long can black bears go without eating, drinking or excreting?

5-7 months in closed dens.

Source: Write-up · Exhibit D (No food, water or waste) · Tøien et al. (2011), Hibernation in black bears: independence of metabolic suppression from body temperature, Science (PubMed); North American Bear Center: 5 stages of activity and hibernation

Test Your Knowledge

All quizzes →

5 questions, all from this case file. Answers are revealed instantly.

  1. What is 'walking hibernation'?

    1. The weeks after den exit when metabolism is still low
    2. Sleepwalking in the den
    3. Migration to a new den
    4. A summer nap
    Show the answer

    Answer: A. The weeks after den exit when metabolism is still low About 2-3 weeks after emergence. Source: Write-up · Exhibit A (Walking hibernation) · North American Bear Center: 5 stages of activity and hibernation; Tøien et al. (2011), Hibernation in black bears: independence of metabolic suppression from body temperature, Science (PubMed)

  2. Black bears cut their metabolism to about what share of basal rates?

    1. About 25%
    2. About 90%
    3. About 5%
    4. About 60%
    Show the answer

    Answer: A. About 25% About 25%. Source: Write-up · Exhibit B (Metabolism without the chill) · Tøien et al. (2011), Hibernation in black bears: independence of metabolic suppression from body temperature, Science (PubMed); EurekAlert! (2011): Bears uncouple temperature and metabolism for hibernation

  3. About how much does a black bear's body temperature fall?

    1. About 5-6 °C
    2. About 30 °C
    3. Not at all
    4. To freezing
    Show the answer

    Answer: A. About 5-6 °C Only about 5-6 °C. Source: Write-up · Exhibit B (Metabolism without the chill) · Tøien et al. (2011), Hibernation in black bears: independence of metabolic suppression from body temperature, Science (PubMed); EurekAlert! (2011): Bears uncouple temperature and metabolism for hibernation

  4. How low can a hibernating black bear's heart rate go?

    1. About 9 beats per minute
    2. About 90 beats per minute
    3. About 1 beat per minute
    4. About 45 beats per minute
    Show the answer

    Answer: A. About 9 beats per minute As few as 9 beats per minute. Source: Write-up · Exhibit C (A slow heart) · Tøien et al. (2011), Hibernation in black bears: independence of metabolic suppression from body temperature, Science (PubMed); EurekAlert! (2011): Bears uncouple temperature and metabolism for hibernation

  5. How long can black bears go without eating, drinking or excreting?

    1. 5-7 months
    2. 5-7 days
    3. 2 years
    4. 2 weeks
    Show the answer

    Answer: A. 5-7 months 5-7 months in closed dens. Source: Write-up · Exhibit D (No food, water or waste) · Tøien et al. (2011), Hibernation in black bears: independence of metabolic suppression from body temperature, Science (PubMed); North American Bear Center: 5 stages of activity and hibernation

Cite this case file

Easterling, Marcus. "Ursine Uptime." The Detail Department (DetailEnjoyer), case file DD-681, last updated Dec 18, 2025. https://detailenjoyer.com/case/ursine-uptime/

Permalink: https://detailenjoyer.com/case/ursine-uptime/ · Last updated

Markdown version

Cite a single fact by its ID, for example DD-681-F01 → https://detailenjoyer.com/case/ursine-uptime/#DD-681-F01