A dozen Mexican gray wolf pups are being raised by wild packs in Arizona and New Mexico as biologists mark another season of playing matchmaker to bolster the genetics of the endangered species.
The foster program involves placing captive-born wolves into the dens of established packs as part of an ongoing effort to return the wolves to their historic range in the American Southwest.
U.S. Fish and Wildlife Service biologist Maggie Dwire says this marks the most pups to be fostered in a single season since the technique was first used in 2014.
A zoo in Kansas and breeding programs operated by conservation centers in Missouri and New York helped this year.
For fostering to work, the timing has to be just right. The pups are usually less than two weeks old when they're placed with a surrogate pack.