Biologists Release Eight More Wolves

Eight wolves have been released from pens where they were held for several months, and biologists hope they will form a 10th breeding pack in Yellowstone National Park.

One, an adult female, spent the winter in a pen near the Lower Geyser Basin after killing sheep near Three Forks, Mont., biologists said. She will be killed or sent to a zoo if she attacks livestock again.

The releases bring to at least 71 the estimated number of wolves roaming free in Yellowstone.

This spring, 13 litters were born. Biologists have not been able to count each of the pups, park spokeswoman Cheryl Matthews said.