BLACK BEARS: Birthing

We’re listening to the sounds of Black Bear cubs. This month, bears are resting in their winter dens, and the newborn cubs are maturing alongside their mothers. I’m Jim Metzner, and this is the Pulse of the Planet, presented by the American Museum of Natural History.

“We actually go in and check dens and so February we’ll be going in and checking the females dens and the cubs will be weighing somewhere between three and five pounds by that time.”

Kristina Timmerman is a Principal Investigator with the Earthwatch Institute. She explains that even though the bears mated in the summer, the cubs are born immature, nearly seven months later.

“One unique thing about bears is they have what’s called delayed implantation. The egg is fertilized in June or July but it’s not implanted into the uterus until sometime in the winter. And that’s done primarily for food reasons — the winter is too long for the cubs to go all the way through as cubs separated from the mother physically. So the cubs are actually born as very small creatures – almost like a marsupial. They’re born and then they crawl and they find a teat and that’s where they mature.”

In the future months, we’ll check in on the bear cubs as they leave their dens in the spring.

If you know of a seasonal event occurring in your neck of the woods, we’d like to hear about it. Write to us at Pulse of the Planet, PO Box 22, Croton, NY, 10520. That’s PO Box 22, Croton, NY, 10520. Our email address is pulse@igc.org. That’s pulse@igc.org.

Pulse of the Planet is presented by the American Museum of Natural History. I’m Jim Metzner.

BLACK BEARS: Birthing

Baby bears are born while their parents are hibernating, and they spend their first months maturing alongside their resting mothers.
Air Date:02/17/1998
Scientist:
Transcript:

We're listening to the sounds of Black Bear cubs. This month, bears are resting in their winter dens, and the newborn cubs are maturing alongside their mothers. I'm Jim Metzner, and this is the Pulse of the Planet, presented by the American Museum of Natural History.

"We actually go in and check dens and so February we'll be going in and checking the females dens and the cubs will be weighing somewhere between three and five pounds by that time."

Kristina Timmerman is a Principal Investigator with the Earthwatch Institute. She explains that even though the bears mated in the summer, the cubs are born immature, nearly seven months later.

"One unique thing about bears is they have what's called delayed implantation. The egg is fertilized in June or July but it's not implanted into the uterus until sometime in the winter. And that's done primarily for food reasons -- the winter is too long for the cubs to go all the way through as cubs separated from the mother physically. So the cubs are actually born as very small creatures - almost like a marsupial. They're born and then they crawl and they find a teat and that's where they mature."

In the future months, we'll check in on the bear cubs as they leave their dens in the spring.

If you know of a seasonal event occurring in your neck of the woods, we'd like to hear about it. Write to us at Pulse of the Planet, PO Box 22, Croton, NY, 10520. That's PO Box 22, Croton, NY, 10520. Our email address is pulse@igc.org. That's pulse@igc.org.

Pulse of the Planet is presented by the American Museum of Natural History. I'm Jim Metzner.