Skip to main content

A holiday gift: sloth bear birth

Posted by: Caileigh Robertson, Communications

We’re capping off the year with yet another significant birth: an endangered sloth bear. Born Dec. 18, the tiny cub is off view with its mom, 7-year-old Tasha, in a behind-the-scenes maternity den. Dad, 16-year-old Randy, is staying in his own den right now, giving mom and cub their space to bond, which is a typical family structure for sloth bears.

This screen capture from the internal web cam was taken just moments after the birth of the cub. The tiny size is normal, with an average birth weight for sloth bears at 10.5-17.5 ounces (300-500 g). Photo by Woodland Park Zoo.

To minimize any disturbance to the family, zookeepers are keeping their distance, monitoring the new family via an internal web cam to keep their eye on things and make sure the cub continues to nurse and bond with mom.

This is Tasha’s first cub, but her motherly instincts kicked in immediately. Right after the birth, she built two large mounds of hay in the maternity den to support the new cub. With the web cam set up, we are able to see the two bonding and can hear the cub vocalizing and nursing normally.

Sloth bears are bears, but not sloths. Why the funny name? They were initially classified as bear sloths due to their perceived slow gait and ability to climb trees. Not until 1810 did the classification change; for the sake of simplicity, the name was switched to sloth bear. Photo by Dennis Dow/Woodland Park Zoo.

Sloth bears are born extremely small and blind at birth. They open their eyes at about 3 weeks old and can walk at 4 weeks. Unlike other bear species, sloth bear mothers carry cubs on their back when cubs reach about 2 months.

With fewer than 50 sloth bears in North American zoos today and fewer than 10,000 remaining in the wild, we are thrilled to welcome this rare, new addition. This breeding was recommended under the sloth bear Species Survival Plan (SSP), a cooperative breeding program to ensure genetic diversity and demographic stability among North American zoos.

A look at the new exhibit plans for the sloth bears at Woodland Park Zoo. Rendering by Mir, courtesy of Woodland Park Zoo.

Many of you have already joined us in helping to build the next amazing exhibit at Woodland Park Zoo—a new, Asian tropical forest-inspired home for sloth bears, tigers, tropical birds and small-clawed otters.

Sloth bear Randy shows off his powerful vacuum-style eating in this video. Produced by Ryan Hawk/Woodland Park Zoo.

The current sloth bear exhibit is off view to the public right now as construction is underway for these new exhibits. Upon completion of the exhibit complex, the zoo’s sloth bears will move into a new, state-of-the-art home with logs for grub-slurping, pits for breaking bones to get to yummy marrow, and mounds for digging. The $19.6 million exhibit project, part of the zoo’s $80 million MoreWonder More Wild Campaign, will replace the 60-year-old infrastructure that critically endangered tigers and sloth bears currently inhabit at the zoo.

You can learn more about the exhibit project and how you can help make it happen at


Anonymous said…
I always call them the Gene Simmons bears because of the similar hair styles!
Anonymous said…
This comment has been removed by a blog administrator.
Anonymous said…
Hmm, looks like a spammer slipped past us. Thanks for the alert! We deleted the comment.
Joyce said…
They remind me of a Newfoundland dog I used to own. Because of the hair. Very little undercoat, and plenty of guard hairs. I also enjoy their pendulous lips. That sort of reminds me of giraffes...
Teezy said…
Ok, I don't normally go nutty for baby animals BUT I MEAN COME ON I can't wait until the little cub is a rumble tumble play machine!!!!
Anonymous said…
I LOVE the vacuum inhale eating!! What a riot! Hope we will perhaps be able to do that when the exhibit is finished!?! Would have to have some sort of monitoring system so people can't just be feeding the poor guys all day and night! Fun, thanks.
Anonymous said…
Love how you keep us informed and with phots if the new members of the Wooland Park Zoo. Keep up the good work, can't wait see the new areas.
A long time WPZ member