Black Bears Return
By the time Big Bend National Park was established in 1944, there were virtually no resident bears in the Big Bend area. Shooting and trapping by ranchers, federal predator control agents, and recreational hunters, and loss of habitat due to settlement and development contributed to their decline. Individual bears occasionally wandered in and out of the park from Mexico, but only scattered sightings were reported from the 1940s through the 1980s. In 1969, and again in 1978, female bears with cubs were seen in the Chisos Mountains. Still, bears were extremely rare in the park.
Habitat and Habits
Although bears are occasionally observed in the low desert and riparian areas of the park, studies indicate they are mainly restricted to the Chisos Mountains and foothills, where they find abundant food, water, shelter, and cooler temperatures. Some bears, especially males and non-breeding females may live in the low desert year-round, where they can locate food and water in arroyos, around desert springs, or along the Rio Grande.
Black bears are considered to be omnivorous, but their diet has been found to be primarily vegetative matter. Favorite foods include acorns, piñon nuts, madrone, juniper, and sumac berries, sotol hearts, persimmon and cactus fruits, and grasses. Bears will also consume insects, carrion, and may occasionally prey upon deer and javelina. During late fall, bears may accelerate their daily food intake as they prepare for winter.
Black bears do not enter true hibernation in Big Bend. Due to the area's mild climate and the availability of food, black bears are dormant for only three to four months (January–March) each year. When their metabolism slows during the winter months, they spend time resting in dens or surface beds. However, they are awake much of the time, and may periodically emerge to forage.
Black bears mate during the summer, so some female bears are pregnant throughout the fall and early winter. Cubs are born in February and stay in the den with their mother until April. The cubs weigh less than one pound at birth, and gain approximately 30 pounds during the first summer. A healthy adult bear in Big Bend can weigh 200-400 pounds and stand five to six feet tall.There are approximately 8–12 adult bears living in Big Bend, and biologists believe the environment has supported 25 to 30 bears. Though, as with most creatures in a desert environment, fluctuations in their numbers occur from time to time.