Despite her three most recent cubs dying, Toronto Zoo officials want to continue a breeding program to help the species survive, mammals curator Maria Franke said Tuesday.

The 11-year-old may get a third chance following the completion of a investigation into why the three baby bears died within three days of being born last Thursday.

"We're still kind of regrouping after the weekend," Franke said.

One male died soon after their births, she said. The surviving sister and brother were found dead overnight Sunday, the zoo said.

Their mother, Aurora, rejected three previous cubs last year, killing two before the third was saved by zoo staff.
That son, Hudson, is doing well at the zoo after being "hand-raised," Franke said.

Little is known about breeding and mothering in the wild, but the latest trio fathered by the same male, nine-year-old Inukshuk, "were being mothered, nurtured and nursed," she said.

Tissue samples were sent for analysis to help determine why they died.

Zoo staff members were convinced Aurora has "demonstrated she can be a good mother," Franke said. "She was calm, doing everything a polar bear should do."

"It's really positive news" for the Toronto Zoo polar bear program that combines research, education and possible future breeding as part of its dedication to preserve the species, Franke said.

About 60% of the world's 20,000 to 25,000 polar bears live in Canada, mostly in the Arctic Circle.