NATURAL HISTORY

MEXICAN GRAY WOLF (in Spanish, el lobo) } Canis lupus baileyi
FAMILY: Canidae

DESCRIPTION: Roughly five feet in length, Mexican gray wolves generally weigh between 50 and 80 pounds. Their coats are buff, gray, and rust colored, often with distinguishing facial patterns. They have large heads with thick muzzles, bushy tails, oversized paws, and long legs. Wolves are known for their keen sense of smell, excellent hearing, and binocular vision. Mexican gray wolves are the smallest of all the gray wolf subspecies in North America.

HABITAT: Mexican gray wolves are found in a variety of habitats, including mountain woodlands and the Chihuahuan and Sonoran deserts.

RANGE: Historically, Mexican gray wolves were found throughout southwestern Texas, southern New Mexico, southeastern Arizona, and as far south as central Mexico. Today, reintroduced wolves are limited to the Gila Headwaters ecosystem in eastern Arizona and western New Mexico.

MIGRATION: Wolves do not migrate seasonally, except in areas where prey animals migrate to lower elevations in winter and wolves follow (for instance, when elk on the Apache National Forest migrate to the San Carlos Apache Reservation). In most current Mexican wolf home territories, this is not the case. Regular travel through home ranges is a constant for wolves. Males and females disperse to set up new territories or reclaim lost habitat, and they can travel hundreds of miles; territory sizes are a function of prey density.

BREEDING: The Mexican gray wolf lives in packs of four to nine animals, consisting of two adults and their offspring. The alpha pair will mate for life, and they normally are the only breeding animals in the pack. Mexican gray wolves breed in February and March, and following a gestation period of approximately 63 days, the mother gives birth to four to seven pups. A pack will establish its territory, ranging up to several hundred square miles.

LIFE CYCLE: The lifespan of a Mexican gray wolf is six to eight years.

FEEDING: Mexican gray wolves are carnivores, preying on elk, mule and white-tailed deer, pronghorn, javelina, rabbits, and other small mammals.

THREATS: Mexican gray wolves were trapped, shot, and poisoned to near extinction, and today human activity still poses the greatest threat — particularly U.S. government-sponsored predator control on behalf of the livestock industry. Poaching is the other primary threat to the wolf.

POPULATION TREND : By the early 1930s, Mexican gray wolves had been eliminated from the United States, and for several decades the government maintained a hunter on the border to kill wolves migrating north from Mexico. Beginning in 1950, the U.S. Fish and Wildlife Service extended its extermination program into Mexico with shipments of government-produced poison and its own salaried hunters. The Mexican gray wolf was listed as endangered in 1976. Reintroductions began in 1998, yet by 2007, the Service had shot 12 wolves, accidentally killed 18 as a consequence of capture and captured 37 wolves that so far have been kept in captivity (most for a long time). The counted number of adult gray wolves remaining in the wild at the end of 2023 was 257. Approximately 300 wolves survive in specialized facilities, zoos, and museums as part of a captive-breeding program.

Photo © Robin Silver