The pack of wolves on display at the International Wolf Center in Ely grew by two Monday, when two pups were introduced.
The pups, Aidan and Denali, have been at the center since May but have been segregated from the other four. The two were born in Forest Lake, Minn, at the Wildlife Science Center.
The center has a pen that's about the size of a football field, which curators say can easily hold eight wolves. With the two additions Monday morning, the pack now numbers six.
Interpretive Center Director Sharee Johnson says there were hopeful signs that Monday's introduction would go well.
"All through the summer we've been watching behavior," she said. "We've been acclimating them to each other through some fencing. The adult wolves have been showing keen and proper interest in the pups."
Johnson says one sign of acceptance is when adult wolves regurgitate their food and let the pups eat it, which she expected would happen some time Monday.
Johnson says the center introduces pups every four years so the middle-aged wolves will turn their attention to nurturing young animals, instead of making an early attempt to oust the pack's older leaders.
All the wolves have been raised in captivity and cannot be released into the wild.
The Center also has a seperate pen for retired wolves, which houses animals that have been cast out of a pack, usually because they're too old to contribute to the pack. The center's retired pen currently houses one wolf, Lakota.
The wolves are not eligible to be released into the wild, because they were born in captivity.
Morning Edition Host Cathy Wurzer spoke with Johnson Monday morning, shortly after the pups' introduction.