Black bears in Mexico, an update of literature review

Abstract

Black bears are widely distributed in North America; historically their range included most of northern Mexico. By the middle of the twentieth-century their distribution was reduced to about 20% and by 1994, black bears were classified as endangered. In recent years, however, there has been an increase in the number of black bears sightings in some of their historic distribution, suggesting that black bears in Mexico may be dispersing and recovering historical habitats. In spite of the fact that the black bear is one of the important mammals that inhabits Mexican territory, there is little knowledge concerning its life history. We present information about black bear presence in the Sierra Madre Occidental and Sierra Madre Oriental. Also, we present a review of available research results on habitat, diet and population density. We include a review of peer-reviewed publications, theses, and grey literature, some of which are available only in Spanish. Our goal is to present a country-wide overview to show where studies of black bears have been conducted, where there is need for further research, and to make the information available for researchers in and outside of Mexico. Key words:  current distribution, historical review,  Ursus americanus