Black bears are wild creatures and it is important for us to keep them wild. Please refrain from naming the sow and her cubs to respect them as a wild animals. Also, respect the privacy of the bears and the landowners, to whom we are extremely grateful for their enthusiastic cooperation in allowing us to share this peek into the lives of black bears. People should not approach hibernating bears because disturbance can lead to den or possibly cub abandonment.
Learn more about Pennsylvania black bears at http://bit.ly/PGCBear. Enjoy! And remember, nature can be difficult to watch.
About the camera:
This is a top-notch camera with audio and IR illumination (night vision) provided and powered by
HDOnTap. It can be controlled remotely and has the ability to pan, tilt, zoom. Staff are hoping to capture images/video of the bears as they leave the den and are brainstorming the best way to do this with additional trail cameras.
Where is the bear?
Being under a residential deck is not an unusual denning situation for this region of the state. The sow and cubs are generally not a threat to the residents, nor are the bears affected by the normal human activity around this home. When she leaves with the cub(s), she will most likely head out to the large wooded area behind the home where she'll find a place to teach the cub(s) to climb and search for food.
About bear dens:
While this female black bear found this space under the deck of a residential home a suitable den, winter dens could also be a hollow tree, an excavation resembling a bear-sized groundhog hole, a rock crevice, cavity under large rocks, or in a nest beneath the roots of fallen trees. Bears line their dens with bark, grasses and leaves. Females tend to select more sheltered sites than males. Males den alone, as do pregnant females (they give birth in the den). Females with first-year cubs den with their young. To our knowledge, an adult male has never been documented in a female’s den, not in Pennsylvania research nor any other state’s research. Adult females will, on rare occasion, reunite with their 2-year-old offspring and have cubs at the same time in the den, but never an adult male.
What is that sound?
The sound of a nursing/purring cub sounds like a car that trying start that just won't turn over. Sows communicate to their cubs with low grunts, huffs and mumbles.
How many cubs are there?
We’ve only seen one. Litter sizes range from one to five, with three most frequent in Pennsylvania. Females give birth in the January while in the winter den. Newborns are covered with fine dark hair, through which their pink skin shows. At birth, they are about nine inches long and weigh 10 to 16 ounces. Their eyes open after about six weeks. A female black bear generally raises one litter every two years. In most cases cubs den with their mothers for their first winter. Most females breed for the first time when 2 1/2 years old.
What do we know about this sow?
Staff estimate that she is about 225 pounds. The adult female has ear tags that indicate she previously was handled by Game Commission staff. While video from the den has not clearly shown the numbers on those tags, as the days pass, and especially as the bears move more, the tag numbers seem certain to provide some details about the bear’s past. If you get a screen shot of the eartag, please let us know!
About snow melt and rain:
It is not uncommon for female bears to use dens with less overheard shelter. Although females with cubs tend to use more sheltered dens, many frequently den in the open with only a few twigs overheard. Cub survival is high in both situations. If a den gets too wet during the spring thaw, the sow may move the cubs to a dryer nearby spot, but this particular dens appears to be fine.
About ear tags:
The Game Commission monitors bear populations statewide by tagging approximately 800 bears each summer, and then watching for the recovery of those tags in the fall harvest. Tags are made of stainless steel and look silver when first put on a bear, but dull to a brownish tin color as they weather. The tags crimp over the top leading edge of the ear, close to where the ear attaches to the head. Tags are about ½ inch wide and 1½ inches long. A unique ID number is stamped on each tag, along with the words PA Game Commission. Each county in the primary bear range is assigned a tagging quota so that tags are well distributed across the state, and Game Commission staff in those counties work toward that quota each summer. Any bear that is captured, regardless of the situation, receives one of these tags in each ear. Both ears are tagged incase one tag would get lost. Numbers on the tags are generally 4 or 5 digits long and consecutive. If a bear is recaptured with only one tag and a replacement tag is added, the numbers would no longer be consecutive. Generally, lower numbers are older bears. Some bears are captured in nuisance situations, and some are simply captured for the purpose of meeting the tagging quota without any history of nuisance activity. It is impossible to tell the reason for capture without looking up the ID number stamped on the tag. And, because a tag is placed in each ear, seeing a bear with only one tag simply means that the other has pulled out. A bear with a tag in each ear could have been captured once or multiple times; again, history can only be determined by looking up the ID number in the database. In other states, tag color and style or number of tags may signify something, but not here in PA. The warden in this district once recaptured bear 3646 and she was 35 years old.
About collared bears:
We only radio-collar bears when a research question requires it. For example, the Game Commission currently has two active bear research projects using radio-collars. In one, we are radio-collaring bears with mange to study treatment options and survival, and in the other, we are radio-collaring adult females to monitor reproductive parameters such as age of first reproduction and litter size. The bear in this den is not radio-collared. If you see a bear with a radio-collar, it simply means that bear is being monitored to answer some question considered important to the overall management of bears in Pennsylvania.
Do they move much?
It is close quarters under the deck and the sow must lay on her side to nurse. She does move now and then but doesn't expend much energy while in the den. As the cub(s) get older there will be more and more movement. In winter, bears den up and become dormant. They lapse into and out of a deep sleep, from which they may be roused. Body temperature is not drastically reduced though respiration and heart rate might decline. They do not urinate or defecate while dormant. Cubs begin walking at around eight weeks old.
What happens when they leave?
The sow will leave with the cub(s) when they are about three months old (typically by early April in this region). There might be activity just outside the den for a while, but, once the sow decides to go, she typically doesn't come back. She'll take the cub(s) to a wooded area and create a daybed, around which she'll teach them to climb trees and find food. They'll be weaned by about seven months old and by fall should weigh 60-100 pounds. In many cases, cubs den with their mother for their first winter.
Living with black bears:
If you're out at dawn or dusk, or where hearing or visibility is impaired (roar of fast moving water, thick vegetation), reduce your chances of surprising a bear by talking or making noise. Learn more about what to do if you encounter a bear at
Monday, March 4, 2019: Celebrating Pennsylvania’s bountiful black bears. Black bears are the only species of bear found in the eastern U.S.. As we move through March, the cubs will become more visible and active; early in the month we may see the sow's back much of the time. Cubs are born around the middle of January and most bears with newborn cubs emerge from their dens in the first week of April. Bears don't typically den under porches or houses. Bears are alert and active during hibernation; they just don't leave the den or take in any food or water. The mother bear will groom and