5 Mexican gray wolf pups born at Illinois zoo

BROOKFIELD, Illinois -- The Brookfield Zoo has welcomed five new Mexican gray wolf puppies.

Five-year-old Zana gave birth to a litter of five pups on April 22. The zoo participates in "cross-fostering," which is the transfer of young pups from one litter to another litter of a similar age.

In this case, two pups from Zana's litter were placed in a wild pack from New Mexico, and two wild-born puppies were placed in the zoo's pack.

The pups - one female and four males - are expected to emerge from their den in the next few weeks, zoo officials said.