Record Number Of Mexican Gray Wolf Pups Cross-Fostered This Spring

Jun 7, 2021

A record number of captive-born endangered Mexican gray wolf pups have been placed in wild dens this year. It’s a process known as cross-fostering and is designed to increase genetic diversity in the struggling species. KNAU’s Ryan Heinsius reports.

This undated image provided by the U.S. Fish and Wildlife Service's Mexican Wolf Interagency Field Team shows a litter of pups before being placed into a den in the wild as part of the agency's cross-fostering program in southwestern New Mexico.
Credit U.S. Fish and Wildlife Service via AP

Twenty-two pups were sent to be raised by wild surrogate parents in Arizona and New Mexico during April and May. Wildlife managers and biologists have prioritized the process in recent years as they attempt to bring Mexican wolves back from the brink of extinction. According to the Arizona Game and Fish Department, pups introduced to wild packs have about a 50% survival rate, similar to wild-born pups.

The species has suffered from a lack of genetic diversity, hobbling recovery and limiting population growth. But officials say at least a dozen cross-fostered Mexican wolves are still living in the wild and some have produced pups themselves.

Some conservationists, however, say the status of many cross-fostered wolves isn’t known, and they want captive-born family groups released in the wild instead. The most recent count this year showed at least 186 Mexican wolves in the wild, a 14% increase from the previous year.