The Mexican grizzly bear - Ursus arctos nelsoni: these bears were reported to be abundant in northern Mexico in the early 1900�s. There were numerous bears in the states of Baja, Sonora and Chihuahua. This subspecies of brown bear also occurred in the United States in New Mexico and Arizona. The last confirmed sightings in Mexico were in the Sierra del Nido Mountains (central Chihuahua) in the late 1950�s. There were reports of grizzly bear poisonings in the same area as late as the winter of 1964.
In May 1980, a research study was conducted as part of informal cooperative agreement between the US and Mexican governments. It revealed sufficient food and secluded habitat for grizzly bears to exist undetected.
This study yielded large tracks with blunt tipped claws, large (50 kg) overturned rocks, and a 25 minute observation of what the expert crew determined to be a grizzly bear. Jonkel (1980) concluded that due to the abundant food, isolated habitat, wariness of the bears and the grizzly bears ability to survive at low population levels, grizzly bears may still exist in Mexico.
At that time, about 20 year after the last reports of grizzlies, they could still be part of a surviving population, given the 20-25 year life span of bears. Could they still be persisting in Mexico today, 30 years later?
No one can answer that for sure. Although the official line is that �a few brown bears may still exist�. There is little or no money for national parks and reserves in Mexico. So land is set aside privately, sometimes in large tracts. In areas of privately protected land in Mexico there is talk of re-introducing the grizzly bear, Mexican wolf and bison. It�s been done for bighorn sheep and pronghorn antelope. And decades ago local ranchers decided to stop killing black bears and protect them instead. Black bear populations have since rebounded.
Could we see grizzly bears living in the southern end of their range? It remains a possibility. Then there is the talk of re-introducing them back into their former range in New Mexico�
References:
www.nmwild.org/wildlife/grizzly-bear
national geographic.com
Grizzly_and_Brown_Bears
www.bearbiology.com
Julie L. Hopkins
Photo credit: Jan van der Crabben