Defenders Celebrates New Record for Mexican Gray Wolf Cross-Fostering Program

Twenty-seven captive-bred Mexican gray wolf pups have been successfully fostered this spring into wild packs, the U.S. Fish and Wildlife Service confirmed. In partnership with FWS, Defenders of Wildlife sponsors wildlife technicians who work alongside the Mexican Wolf Interagency Field Team to place pups into the wild.

“This is a critical initiative for a species struggling to overcome existential genetic challenges,” said Craig Miller, Defenders of Wildlife senior representative for Arizona. “We're grateful to the field team's hard work to improve the odds for Mexican gray wolves. Despite challenging working conditions, limited resources and political constraints they’re creating a future for one of the most imperiled animals on Earth.”

The 2024 cross-foster count is up from the 16 captive pups placed into the wild in 2023. Since its inception nine years ago, the cross-fostering program has placed nearly 130 pups into wild packs located within the Mexican Gray Wolf Recovery Area across Arizona and New Mexico.  

Mexican gray wolf pups, either born in the wild or a breeding facility, have a low chance of survival in the wild. Since 2016, less than 30 captive-bred pups survived their first year in the wild and only 18 survived to adulthood.  

Agencies will monitor the packs and provide supplemental food caches for the first six months after fostering to ensure these genetically viable pups grow to adulthood and increase the genetic pool of the wild population. However, cross-fostering is only one piece to recovery for the Mexican gray wolf. In addition to this work, FWS must expand habitat to encourage Mexican gray wolf dispersal north into the Grand Canyon ecoregion and south beyond the border.  

“It is crucial not only to enhance the genetic diversity of the wild population but also to remove artificial boundaries that hinder the wolves from accessing other secure habitats in the region. By doing so, we can greatly enhance the wolves’ chances of successful recovery," Miller said.