Western Lowland Gorilla
Southeast Nigeria, Cameroon, Rio Muni, Gabon, Congo in Angola
Floor of mountains and secondary forests with damp, hot climate.
While the gorilla is the largest of the apes, the western lowland gorilla is the smallest of the three gorilla subspecies. There is obvious sexual dimorphism. Standing height for males 5 feet 6 inches, arm span 7 feet 8 inches, weight 325 pounds. Females are only half the weight of the males. Coat is black, brown or gray, with the adult male having a "silver back" saddle reaching to the thighs. This saddle is less defined than in the eastern lowland gorilla. Hands, face, feet, and chest are black and naked. The skull is massive with heavy brow ridges. The nose is the easiest way to differentiate individuals. It has an overhanging tip (unlike the eastern lowland gorilla). Eyes are small and reddish-brown eyes. Ears are small and set close to the head. Dentition of 32 teeth. The ape has powerful canines, especially in the males. Arms are long, legs short, with the bulk of the weight carried on the legs. Short broad hands sport a short and stubby opposable thumb.
This ground-living ape is diurnal, eating near its nest, moving every one to three days, depending upon food supply. Males nest on the ground, females and young nest on a platform built less than ten feet from the ground. Locomotion is quadrupedal with knuckle-walking. Bipedalism is seen only during the chest-beating display, when a male can run up to 20 feet. Infants are able to use an arm-swinging locomotion that they will outgrow. Groups are of from five to 30, consisting of a single dominant male (silver-back), one or two black-backed subadult males, about six adult females and up to ten babies and juveniles. The groups are well integrated and peaceful. Only the silverback mates with the females. Young silverbacks leave the group and live alone until they can coax or kidnap females of their own. Males may live in bachelor troops. While females may change groups, they never live alone. Social grooming is common between group and family members. Communication skills are both vocal and full-body. Twenty-two different sounds have been recorded. Gorillas are more vocal during mating. Well-known is the silverbacks display. He will beat his chest, making hoots and growls, put a leaf between his lips (symbolic feeding), stand, hunch shoulders, beat his chest and charge bipedally, finally dropping to all fours.
Menstrual cycle lasts 31 to 32 days. Estrus is marked by a slight swelling of the genitalia. Gestation is 258 days. A single infant is born, with twins being rare, with a birth weight of 1800 to 2400 grams. There is no fixed birth season. Infants have a small white tuft on the rump until they are four years old. During this time they may take liberties with other members of the troop with no repercussion. Skin turns from the pinkish gray of the newborns to dark gray or black by one year. Babies are weaned at about two years, but stay in their mothers nest until they are about three. Females mature at six to eight years, males eight to ten years. Backs begin to silver in males at about 11 to 13 years. Females breed about every 3 to 5 years. Maternal behavior is learned, not instinctive.
Though they may look fierce, Gorillas are "gentle giants," eating only vegetation and only becoming aggressive when threatened. Gorillas neither make nor use tools. Water is taken from greens and fruit; they cannot swim.
All training at Utah's Hogle Zoo is done through positive reinforcement. Our apes are trained everyday through protected contact, which means that there is always a barrier between the keepers and the apes for safety. The apes have learned behaviors such as open mouth, teeth brushing, body part presentation and injection. These behaviors all help with the daily and medical care for the animals.
Enrichment is novel items added to an animal's environment to encourage natural behaviors and stimulate the mind , such as climbing, foraging and investigation. The enrichment that we provide the apes is not always food related. Bubbles, sheets, paper bags, barrels, puzzle feeders, and a variety of scents are just a few of the over 200 creative items we utilize for ape enrichment.
About Our Animals:
The Zoo currently houses four gorillas.
- Tino (male): wild-caught in the 1970's. Came to Hogle Zoo in 1986
- Husani (male): born December 14, 1991 at the Bronx Zoo. Came to Hogle Zoo in 2010
- JoRayK (female): born November 2, 1977 at Lincoln Park Zoo. Came to Hogle Zoo in 2011
- Jabali (female): seventh offspring of JoRayK born May 29, 2004 at the Denver Zoo. Came with JoRayk to Hogle Zoo in 2011.
The biggest threat to the survival of African wildlife like the gorilla is no longer habitat loss, it's bush-meat. What is Bushmeat? It is the illegal, commercial and unsustainable trade in wildlife meat. Why has it become a concern? People have hunted in the past, but only to feed their families. Today, with the human population increasing dramatically, the demand for bushmeat has increased. Bushmeat is a primary source of protein for village families. Urban consumers have increased their demand for bushmeat to connect with their traditional ways. With global demand increasing for bushmeat, hunting can also be a significant source of income for village families. The bushmeat crisis is now the most significant immediate threat to the wildlife population of Africa, like gorillas. Adding to the threat is the economic demand for logging and mining. Roads built for logging and mining companies allow easy access to the forest. The global demand for timber products intensifies the devastating effects of bushmeat hunting. Who is affected by the crisis? All wildlife species are threatened by the crisis, especially gorillas, elephants, duikers and bush pigs. Once thse species have been eradicated the hunters trap smaller primates, rodents and birds with snares. Unfortunately, 95% of the animals caught in snares are not recovered by hunters. They are either eaten by other animals or die of starvation. Conservation International and the World Conservation Union report that one-third of the world's great apes, monkeys, lemurs and other primate species are now threatened with extinction, many by the bushmeat crisis.
|Did YOU Know?|
|Gorillas are identified by their nose-prints. Just like every human has their unique fingerprints, every gorilla has its own unique nose-print.|
|Height:||Approximately 5.5 feet|
|Wild Diet:||Ground plants, leaves, bark, stems, roots, vines, bamboo. Sometimes young gorillas will climb trees and throw down fruit to older gorillas.|
|Zoo Diet:||Monkey chow, apples, carrots, celery, kale, lettuce|
|This is an ssp animal|
|CITES Status:||Appendix II|
|Where at the Zoo?||Great Ape Building|