Mexico is home to one thriving bear species, while another has vanished. This article explores the bear species that have inhabited Mexico, their current distributions, and conservation efforts.
Bear Species in Mexico
The American Black Bear (Ursus americanus) is the only bear species found in Mexico. These medium-sized bears exhibit varied coat colors, ranging from black to brown or even blonde, often featuring a pale muzzle and sometimes a white chest marking. Adult males typically weigh between 90 to 180 kilograms, while females range from 45 to 110 kilograms. American Black Bears are highly adaptable omnivores, consuming a diet that includes plants, fruits, nuts, insects, and occasionally small mammals.
Mexico was once home to the Mexican Grizzly Bear (Ursus arctos nelsoni), a subspecies of brown bear. Known as “el oso plateado” (the silvery bear) due to its distinctive silver-tipped fur, this bear was among Mexico’s largest land mammals, reaching up to 1.82 meters in length and weighing an average of 318 kilograms. Its historical range included the northern territories of Mexico, extending into parts of the southwestern United States. The Mexican Grizzly Bear faced intense pressure from hunting and habitat destruction, particularly due to cattle farming expansion. By the 1930s, the species became rare. Despite protective measures, illegal hunting continued, and the last confirmed Mexican Grizzly Bear was killed in 1964 in Chihuahua, leading to its presumed extinction.
Current Habitats
American Black Bears in Mexico primarily inhabit the northern states, including Sonora, Chihuahua, Coahuila, Nuevo León, and Tamaulipas. Populations are also present in Zacatecas and Durango. Their distribution is closely linked to the mountainous regions, particularly the Sierra Madre Occidental in western Mexico and the Sierra Madre Oriental in the east. These mountain ranges provide suitable environments with ample food sources and cover.
Black bears thrive in a variety of environments within these regions. They are found in temperate grasslands, mountain pine forests, and woodlands composed of juniper, piñon pine, madrone, oak, and persimmon. These areas often include “sky islands”—isolated pockets of higher elevation habitat surrounded by more arid terrain—which offer crucial resources like food, water, and denning sites. While their historical range covered much of northern Mexico, the current distribution represents about 20% of their original habitat.
Protecting Mexico’s Bears
American Black Bears in Mexico face significant threats. Habitat loss and fragmentation are major concerns, driven by deforestation, agricultural expansion, and increasing human presence. Human-wildlife conflict also poses a challenge, as bears are sometimes perceived as a threat to crops and livestock, leading to retaliatory killings. Illegal hunting and poaching further endanger these populations, along with risks associated with infrastructure development like roads, which can lead to vehicle collisions.
Various conservation efforts are underway to protect American Black Bears in Mexico. The species is classified as endangered within the country. Strategies include the establishment of protected areas and the identification of wildlife corridors to maintain connectivity between fragmented habitats. Community education programs aim to reduce human-bear conflicts and foster coexistence. Strengthening anti-poaching initiatives and conducting ongoing research are important for the long-term survival of these bears in Mexico.