Mexican Gray Wolf

Mexican Gray Wolf,  Canis lupus baileyi

Mexican Gray Wolf, Canis lupus baileyi. Photograph taken within the confines of the Arizona-Sonora Desert Museum, Tucson, Arizona, February, 2022.

Mexican Gray Wolf, Canis lupus baileyi. Photograph taken within the confines of the Living Desert Zoo and Gardens, Palm Desert, California, March 2011. Photograph courtesy of Dr. Tom Bartol, Carlsbad, California.

The Mexican Gray Wolf, Canis lupus baileyi, is the smallest subspecies of Gray Wolf, Canis lupus, in North America. They are a member of the Canidae family of Wolfs. The family consists of thirty-six species placed into thirteen genera. There are eight species in the Canis genus. The Mexican Gray Wolf is known in Mexico as El Lobo.

Mexican Gray Wolves can have various colors including dark brown, cinnamon, tawny, cream, grizzled, and brindle depending on the region. Unlike other North American Gray Wolves, there are no solid black or white variations within the species. The backs of their ears and the sides of their body range from cinnamon to brown in color. Their face and underside is typically white to cream. The dorsal side of their neck, back, and tail are grizzled black with shades of brown. Mexican Gray Wolf fur is long and thick, with two coat layers. Their undercoat is thick and traps air, providing insulation. The visible guard coat is long and protects the undercoat from getting wet. In early spring, they shed for approximately a two week period, losing all of their undercoat at once in preparation for the warmer summer months. Mexican Gray Wolves have a deep chest and a large head with rounded, erect ears. Their muzzle is thick with a large nose pad. They have powerful jaws and 42 strong teeth that they use to hold their prey, cut tendons, and crush bones. Their legs are long with large, strong feet that enable them to travel long distances, grip the terrain in all weather conditions, bury food caches, and dig burrows. Mexican Gray Wolves measure between 1.4 m (4 feet 7 inches) and 1.7 m (5 feet 7 inches) in length, including their 36 cm (14 inch) to 43 cm (17 inch) tail. They stand between 66 cm (2 feet 2 inch) to 81 cm (2 ft 8 inches) in height at the shoulder, and weigh 27 kg (60 lbs) to 36 kg (80 lbs). Sexual dimorphism is displayed with the males growing larger than the females.

Mexican Gray Wolves are highly social and live in packs. Each pack has a complex social structure that includes the breeding adult pair, consisting of the alpha male and female, and their offspring. The hierarchy of dominant and subordinate individuals within a pack helps it to work as a unit. The size of a pack depends upon food availability. In regions where prey is smaller, such as deserts, a pack may have 7 or fewer members. In areas where prey is larger, a pack can contain 30 or more members. Mexican Gray Wolves typically travel with their packs and establish a home territory that ranges from 78 to 130 square kilometers (30 to 50 square miles). Their territories are defined with scent markings, such as urine and feces, and vocalizations including barking, growling, and howling. Mexican Gray Wolves are monogamous, with only the pack’s alpha pair breeding each year. The breeding season lasts from mid-February to mid-March. After a gestation period of approximately 63 days, the alpha female gives birth to a litter of 4 to 7 pups. The pups are reared in a den that is selected by the female, who prefers a location that is secluded and close to water. Mexican Gray Wolves often dig their dens in rock crevices, under root balls of fallen trees, or in the ground on steep, rocky slopes. Some females will return to the same den site each year, while others pick new locations. A few days before she gives birth, the pregnant female will dig the den herself. While the inside size and depth of a den varies significantly, all dens have a narrow opening to keep out predators. Some may have multiple channels and tunnels, while others are much simpler. In every den there is one larger area where the female births her pups and nurses them. When the den is ready and the time comes, the female will enter her den in preparation for the birthing process. As a part of this process, she will pull tufts of thick fur from her belly. This is done to better expose her nipples for nursing, and to possibly provide more heat to her pups when sleeping and nursing. The pups are altricial, being born blind and helpless, and the female remains in the den to nurse and care for them. During this time, other members of the pack carry out hunting duties and bring food to the den. Pups begin to emerge from the den at around 6 weeks of age, however, the den will continue to serve as a home base until they are about 8 to 12 weeks old. After that, they are ready to join the rest of the pack and learn how to be a Wolf. Mexican Gray Wolves have lifespans of six to eight years in the wild and up to fifteen  years in captivity. 

Mexican Gray Wolves hunt cooperatively to bring down prey animals, usually larger than themselves. This is accomplished primarily by chasing their prey over large distances. They can reach top speeds of up to 64 kilometers per hour (40 mph). Hunting behavior and strategies vary depending upon terrain and prey size and availability. It takes careful cooperation for a pack to take down large prey, and their rate of success is low. As a result, Mexican Gray Wolves usually feed only a few times a week, eating up to 9 kg (20 lbs) of meat at a time. Their native prey includes elk, mule deer, white-tailed deer, javelina, rabbits, and other small mammals. They occasionally kill livestock, particularly young animals. In addition, they readily scavenge on carcasses of prey species.

Mexican Gray Wolves were once widespread throughout mountainous regions from central Mexico, through southeastern Arizona, southern New Mexico, and southwestern Texas. Currently, they are found only in southeastern Arizona, southwestern New Mexico, and northern Mexico. Mexican Gray Wolves occupy a variety of southwestern habitats including mountain forests, scrublands, and grasslands. They prefer mountain woodlands, most likely due to the favorable combination of cover, water, and available prey.


The Mexican Gray Wolf may be confused with the Great Plains Wolf, Canis lupus nubilus (larger in size and has a coat of gray, black, or buff with reddish coloring; absent from Mexico). 

The Mexican Gray Wolf is the rarest subspecies of Gray Wolf in North America. They are listed separately from the Gray Wolf as an Endangered subspecies under the Federal Endangered Species Act. In the early 1900’s, high cattle stocking rates and declining populations of native prey, such as deer and elk, caused many Mexican Gray Wolves to prey on livestock. This led to intensive eradication efforts. By the mid-1900’s, Mexican Gray Wolves had been effectively eliminated from the United States, and populations in Mexico were severely reduced. In 1976 they were listed by the U.S. Fish and Wildlife Service as an Endangered species, thereby prompting recovery efforts to save the species from extinction. In 1977, the U.S Fish and Wildlife Service and its partners created a bi-national captive breeding program with seven remaining Mexican Gray Wolves. They were first reintroduced to the wild in 1998, marking the first time in thirty years Mexican Gray Wolves were known to exist in the wild in the United States. Reintroduction methods have so far been successful and several populations are currently maintained throughout northern Mexico, southeastern Arizona, and southwestern New Mexico.