WESTERN LOWLAND GORILLA

SCIENTIFIC NAME: Gorilla gorilla gorilla

PHYSICAL CHARACTERISTICS AND ADAPTATIONS: · The gorilla is the largest living primate, with males weighing about twice the size of females. Competition between males for mates likely led to their large size. A larger, stronger male is better able to guard its troop and defend its females from other males than a smaller male. · Like other primates, gorillas have opposable thumbs that enable them to better manipulate, hold, and carry things. · Gorillas walk on the knuckles of their hands and the soles of their feet, known as knuckle-walking. · Intelligence and memory are helpful for knowing where to find the best food sources. · Large teeth and jaw muscles are adapted for chewing tough plants.

Weight Male - Up to 400 lbs, Female - Up to 200 lbs Height 5 to 6 ft

RANGE: Central Africa

HABITAT: Tropical forest

DIET: Wild: Leaves, fruit, and small invertebrates Zoo: Fruits and vegetables (apples, grapefruit, bananas, sweet potatoes, carrots, green beans, celery, kale, escarole, romaine), monkey biscuits, rice bread, hard-boiled eggs, browse (leaves and branches)

REPRODUCTION & DEVELOPMENT: Mating season Year round Mating system Polygynous (one male & several females) Length of gestation 8.5 months Number of young 1 Weight of young at birth 4 to 4.5 lbs Age at weaning 2.5 to 3 yrs Reproductive age Male – 7 to 10 yrs (15 to 20 yrs until they breed), Female – 7 to 8 yrs Lifespan Up to 35 yrs in wild (50 yrs in captivity)

Courtship behavior: Battles between males for leadership of a troop and breeding rights with the females are intense. Generally, males do not successfully breed until they are 15 to 20 years old. Males lure females away from their current troops by showing off their strength and intimidating rival males through chest-beating, roaring, thrashes branches, and sideway dashing.

Raising young: A female carries her infant for the first few months of its life. Infants begin to crawl after nine weeks and can walk around 30 to 40 weeks. Youngsters are not completely weaned until two or three years old. A female only gives birth every four years on average. 3/2010

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SOCIAL BEHAVIOR: · A troop of up to 20 gorillas is led and defended by a dominant male called a silverback. · Gorillas are generally peaceful. They are only aggressive when competing for mates or defending their troops. · Males may travel in bachelor groups or on their own until they can establish their own troop. · Gorillas communicate through a variety of facial expressions, vocalizations, body postures, and displays.

INTERESTING FACTS: · Gorillas are great apes, along with bonobos, chimpanzees, and orangutans. · A gorilla must spend most of its day eating plants to maintain its large size. · Gorillas and humans are close relatives, and share many things in common. They are very intelligent, have emotions and personalities, and live in family groups. · A male gorilla has the strength of up to eight men. · Gorillas recognize each other by face and body shape. Each gorilla has a unique nose print, which researchers use to identify individuals they are observing. · Gorillas usually feed during the morning and afternoon, taking a break to rest during the noon hours. · Gorillas make nests out of branches and leaves to sleep in each night.

CONSERVATION: Status in the Wild: (IUCN—Critically endangered)

What is the Cincinnati Zoo doing? The Zoo supports the Mbeli Bai study located in the Nouabalé-Ndoki National Park in the Republic of Congo. Observations of western lowland gorillas have provided unique insights into their social organization and dynamics. Such information is important to determining the best course of action for gorilla conservation.

What can people do to help save gorillas and their habitat? · If you must buy a new cell phone, drop off your old phone at the Zoo. Recycling it will reduce mining for coltan (an ore used in cell phones) and raise money for the Zoo’s Conservation Fund. · Adopt a Gorilla. Go to www.cincinnatizoo.org, click on “Support the Zoo” and then click on “ADOPT”.

RESOURCES: The Encyclopedia of Mammals, David W. Macdonald, 2006

3/2010

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