(CBS) — For only the second time ever, wolf puppies that were born in a zoo have been placed with a litter of wolves in the wild to help boost the wild population and both times, the puppies came from Brookfield Zoo.

April 25 is when the five Mexican gray wolf puppies were born.

Five days later, things got really busy at Brookfield, which started getting the two strongest puppies ready to travel to Arizona to be raised in the wild with a litter of five there.

“We started the process at 3 o’clock in the morning here at Brookfield Zoo,” said Joan Daniels, associate curator of mammals at Brookfield Zoo.

The zoo had to let U.S. Fish and Wildlife know when Brookfield’s wolf was pregnant so Fish and Wildlife could find a wolf in the wild that had just gotten pregnant.

“The timing is a little bit tricky, but all the dominoes did fall into place and we were able to line up the litters properly,” she said.

Blaze, a Mexican gray wolf puppy born at Brookfield Zoo (Credit: Chicago Zoological Society)

Blaze, a Mexican gray wolf puppy born at Brookfield Zoo (Credit: Chicago Zoological Society)

So on April 30, the two Brookfield wolf pups, Blaze and Brooke, were placed with the Arizona litter in the wild and Daniels says so far so good.

She says the three pups still at Brookfield will be on display in about two weeks.

(Credit: Chicago Zoological Society)

(Credit: Chicago Zoological Society)

Watch & Listen LIVE