There's a baby boom underway at Northwest Trek. Officials at the wildlife park near Eatonville said May 21 that two bison calves and two bighorn sheep lambs were born over the last several days, bringing the total of newborns of each species to three since the latest birthing season began. More newborns are expected in the bison herd and bighorn sheep population. Several Roosevelt elk cows are pregnant, too, animal keepers reported. The news wasn't all good from the baby animal front. A beaver kit that had been expected was stillborn to its 9-year-old mother two weeks ago, said Dr. Allison Case, a veterinarian for Northwest Trek. The kit was full-term and there were no obvious signs of trauma, Case added. The results of a necropsy are pending. The mother is doing well, Case said last week. The new bison calves and bighorn lambs have been sticking close to their mothers in the meadows and on the hillsides of the wildlife park's 435-acre free-roam area, where herds live freely wander through the landscape. Visitors tcan see them and other animals during 50-minute guided tram tours.