The Mexican gray wolf is a subspecies of the gray wolf, commonly referred to as “el lobo”.

Though they once numbered in the thousands, these wolves were wiped out in the U.S. by the mid-1970s, with just a handful existing in zoos. In 1998, the U.S. Fish and Wildlife Service, led by Jamie Rappaport Clark (now president of Defenders of Wildlife), released 11 Mexican gray wolves back into the wild in Arizona.

Although their numbers have grown slowly, they remain the most endangered subspecies of wolf in the world because of compromised genetics, human intolerance and reluctance to release more individuals and bonded pairs to the wild.

Defenders' Impact

As the population slowly recovers, Defenders continues to support scientists and policymakers to find the best path forward, including supporting adult releases and cross-fostering of pups. We also sponsored a Mexican biologist to come to the U.S. to gain experience working with the recovery team to support wolves in Mexico.

Defenders works directly with ranchers and tribal members to implement proven techniques to keep wolves and livestock safe. These include using range riders to watch over livestock, moving livestock away from wolf dens, erecting special fencing and more.

Defenders supports range rider projects on the ground in high conflict areas to reduce conflict and foster coexistence. Defenders also supports a collaborative wildlife technician program which places trained graduate students in the field for six months at a time to assist with monitoring of wolves and livestock and to implement proven non-lethal tools to reduce conflicts.

You can be a part of the solution for endangered species: support our efforts to protect the wild!


Humans pose the greatest threat because of intolerance and misconceptions about Mexican gray wolves. The genetic diversity of Mexican gray wolves also needs careful monitoring and improvement because inbreeding is a serious threat in the wild.

Protection Status
Endangered Species Act
What You Can Do

Speak up for wolves and the continued support of endangered species protections, like the Endangered Species Act.

Support Defenders work in the field and in the courts.

Latin Name
Canis lupus baileyi
60-80 pounds with males typically heavier and taller than females
Up to 15 years in captivity, but 6-8 years in the wild.

Mexican gray wolves once ranged widely from central Mexico throughout the southwestern U.S. including Utah, Colorado and Texas. Today, they can be found only in southeastern Arizona and southwestern New Mexico. Mexican gray wolves are also being reintroduced in Mexico. They prefer mountain forests, grasslands and scrublands.


In 2019 there were 163 individual wolves in 42 packs of two or more animals in the wild in Arizona and New Mexico.


Mexican gray wolves are very social animals. They live in packs, which are complex social structures that include the breeding adult pair (the alpha male and female) and their offspring. A hierarchy of dominant and subordinate animals within the pack help it to work as a unit.


Packs care for the pups until they mature at about 10 months of age.

Mating Season: Mid-February to mid-March

Gestation: 63 days

Litter size: 4-7 pups


Mexican gray wolves mostly eat ungulates (large hoofed mammals) like elk, white-tailed deer and mule deer. They are also known to eat smaller mammals like javelinas, rabbits, ground squirrels and mice.

Black-footed ferret kits
Image Credit
Ryan Moehring/FWS

Protect the Endangered Species Act

Let your Representatives know that protecting imperiled wildlife is an important issue.
Take Action!


- Mexican Gray Wolf Pup - Rebecca Bose - Wolf Conservation Center.JPG

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

Wildlife and Wild Places

Gray Wolf in Yellowstone
Sky Islands
Grizzly bear sow
Red Wolf
Get Updates and Alerts