A male Mountain Gorilla can weigh from 450-500 pounds and, when standing upright, can measure up to six feet. Females are smaller, weighing only about 200 pounds. Of all gorilla sub-species, the Mountain Gorilla has the longest hair. They also tend to be greater in size than most others; with larger jaws and broader faces.
Diet and Habitat:
Mountain gorillas dwell at altitudes as high as 11,000 ft. They prefer the often cloudy, misty surroundings in which they live. Temperatures there can even become frigid at night. Large amounts of vegetation from more than 70 different plant species, including wild celery, gallium, vines, berries, bamboo, roots and bark, provide ample dining opportunities for the Mountain Gorillas. When the bamboo plant sprouts in June and November, bamboo shoots can make up to 90 percent of the their diet. A silverback male may eat up to 75 pounds of bamboo each day; where as females may only consume about 40 pounds per day. Gorillas spend about 1/3 of their day eating, 40 percent of the time resting and sleeping and about another 1/3 traveling. Led by the silverback, gorillas roam around a large range, foraging for food.
Mountain gorillas live in social groups ranging from two to more than 35 individuals. The leader of each group is a mature male called a "silverback," because of the silver hair on his back. A male's hair will start to turn silver around age 11. The silver-back is the center of attention in the group, with the other gorillas congregating around him during periods of rest and play. An average group of 10 individuals might consist of the silverback, one "blackback" (an 8-12 year old male), three or four sexually mature females, and three to six juveniles and infants. To secure a mate, competition between males can become intense. While attempting to lure away females in heat for breeding, battles can erupt if the relatives and troop members of the female notice her anxious suitor. Generally though, Mountain Gorillas are passive and non-territorial creatures. Troops tend to avoid one another.
Reproduction and Rearing:
Females first breed at about age 10; males first breed around age 15. Gestation lasts from eight to nine months, resulting in a baby weighing four to five pounds. A baby is dependent on its mother for three years, while it learns to build nests and forage for food. The mother holds her infant until it is about four months old, after which it is able to ride on her back, clinging to her fur. Females bear a single baby every four to five years.
The Mountain Gorilla is the most endangered of the three gorilla sub-species. In fact, there are no mountain gorillas in zoos today. Humans pose the greatest threat to them -- specifically poachers. Constant scrutiny and persecution of these hunters is needed to protect the gorillas and the natural balance of their habitat. Projects to establish parks and wildlife boundaries free from human encroachment were started decades ago. However, to better ensure that threatening human activity does not occur in these parks, the demand for and trade of gorilla parts must be decreased.
Note: Some information has been excerpted from World Wildlife Fund, and the National Audubon Society's Field Guide to African Wildlife.