Science Diary: Bears – Strange Birth

music; ambience bear cubs

Newborn grizzly bears express themselves with a variety of sounds. This recording comes from a surveillance video at Washington State University’s Bear Center; it’s a video that led to an extraordinary discovery; and a bit of a mystery. Welcome to Pulse of the Planet’s Science Diaries, a glimpse of the world of science from the inside.

HJ: “We had a female her name is Oakley give birth to two cubs on the 31st of December. We actually know this for a fact because Jasmine has been watching all of the recorded video, and she actually saw the birth event. Jasmine came back with an e-mail about two and a half weeks later and said, there’s another cub being born.”

It’s not the presence of a third cub that surprised researchers Jasmine Ware and Heiko Jansen, because triplet bears are common. The remarkable part is that bear three remained in its mother’s womb for an extra 2 1/2 weeks.

“The reasons for it we simply don’t know. We know that the bears can actually mate with more than one male. And so, perhaps what happened was that she had an ovulation, mated, fertilized one egg and then had a replicate of that event occur sometime later. The other possibility is that she had one male fertilize two eggs, but one of these eggs simply took a lot longer to implant. Bears are unique in terms of their reproductive physiology. They fertilize an egg, and then the egg divides into a few cells and then remains dormant for months. And then, after a period of months, it does decide to implant via some mechanisms that aren’t entirely clear either. And then the egg develops. And so, perhaps there was a 17-day window between one egg implanting and the other egg implanting.”

We’ll hear more on grizzly bears in future programs. Pulse of the Planet’s Science Diaries are made possible by the National Science Foundation. I’m Jim Metzner.

Science Diary: Bears - Strange Birth

Triplets typically share a birthday, but three little bears in Washington state have birth dates 17 days apart.
Air Date:05/05/2009
Scientist:
Transcript:


music; ambience bear cubs

Newborn grizzly bears express themselves with a variety of sounds. This recording comes from a surveillance video at Washington State University’s Bear Center; it’s a video that led to an extraordinary discovery; and a bit of a mystery. Welcome to Pulse of the Planet’s Science Diaries, a glimpse of the world of science from the inside.

HJ: “We had a female her name is Oakley give birth to two cubs on the 31st of December. We actually know this for a fact because Jasmine has been watching all of the recorded video, and she actually saw the birth event. Jasmine came back with an e-mail about two and a half weeks later and said, there’s another cub being born.”

It’s not the presence of a third cub that surprised researchers Jasmine Ware and Heiko Jansen, because triplet bears are common. The remarkable part is that bear three remained in its mother’s womb for an extra 2 1/2 weeks.

“The reasons for it we simply don’t know. We know that the bears can actually mate with more than one male. And so, perhaps what happened was that she had an ovulation, mated, fertilized one egg and then had a replicate of that event occur sometime later. The other possibility is that she had one male fertilize two eggs, but one of these eggs simply took a lot longer to implant. Bears are unique in terms of their reproductive physiology. They fertilize an egg, and then the egg divides into a few cells and then remains dormant for months. And then, after a period of months, it does decide to implant via some mechanisms that aren’t entirely clear either. And then the egg develops. And so, perhaps there was a 17-day window between one egg implanting and the other egg implanting.”

We’ll hear more on grizzly bears in future programs. Pulse of the Planet’s Science Diaries are made possible by the National Science Foundation. I’m Jim Metzner.