I recently toured the Toronto Zoo, exciting to me because I’ve never seen it, and exciting to our two-year-old, Alice, because currently her favorite story is a short adaptation of Disney’s animated adaptation of Tarzan, in which many of the characters are gorillas–and one of the Toronto zoo’s star features is called the Gorilla Rainforest.
It’s a recently refurbished acre of land within the two-acre gorilla habitat, which originally opened 26 years ago. The Gorilla Rainforest, which took 7 1/2 years and $6 million to build, expanded the living space for the zoo’s lowland gorillas to four times its previous size. There are also improved viewing facilities and a research station that provides detailed information on the ecology of rainforests and the impact humans are having on them–an impact that could doom the gorillas to extinction as their habitat is destroyed.
If that happens, it will be next door to genocide, because gorillas, along with chimpanzees, are our closest wild relatives. Fossil and genetic information indicate that the ancestors of gorillas and chimpanzees diverged from the ancestors of humans only five to 10 million years ago. As a result, there are many similarities among the three species, including high intelligence.
There are three distinct types of gorilla – the western lowland gorilla (found in western central Africa), the eastern lowland gorilla (found in Eastern Zaire) and the mountain gorilla (found in the mountainous regions of Zaire, Rwanda and Uganda). Almost all the gorillas found in zoos (including those in Toronto) are Western lowland gorillas.
All gorillas share certain characteristics. They’re big (adult males average 1.7 metres in height and weigh 180 kilograms, while females average 1.4 metres and 90 kilograms). They have massive heads and bulging foreheads, with short, hairless muzzles, flat noses, flaring nostrils, small ears and eyes and strong jaws. They have short trunks, and longer arms than legs. They walk on all fours, using the soles of their feet and their curled knuckles, although they will raise up to get a better look at something, when trying to reach for an object, or (in best Tarzan fashion) when beating their chest, a display males put on primarily to intimidate other males.
Gorillas have dark skin and hair that ranges from reddish brown to nearly black. Older males develop a saddle of gray hair across their backs, which is why they’re called silverbacks.
A typical band of gorillas comprises a silverback, one or two immature males, several mature females and some young. Most males leave the band as they become old enough to breed, and eventually form bands of their own or else join up with other “bachelors.” Young females usually join other bands (which prevents inbreeding). Once a silverback has been challenged and defeated, it lives a solitary life, unless it can lure other mature females to join it.
The gorilla life isn’t bad. They typically sleep 12 to 13 hours a night, get up and eat, spend three or four hours just relaxing, move and forage a few hundred metres during the course of the afternoon, then make nests and settle in for another night. Of course, eating is nearly a full-time occupation; gorillas are choosy eaters, selecting their diet from fruits, stems, shoots, flowers, leaves and bark from over 200 species of plants, but a full-grown male eats about 20 kilograms of food or more a day.
Like humans, gorillas mate throughout the year. Females usually conceive for the first time between the ages of 10 and 11; gestation lasts for about 258 days. A newborn gorilla is completely dependent on its mother for care, spending the first few weeks clutching her belly, then beginning to ride on her back at about 16 weeks. They can crawl at nine weeks and walk at 35 weeks; they’re weaned when they’re about two.
Gorillas are capable of elaborate learning; in captivity, gorillas have successfully learned sign language and can communicate with humans using simple sentences. They seem to be more interested in solving problems and have greater memory retention than chimpanzees.
And yet, their greatest threat comes from the supposedly most intelligent animal of all on this planet, humans. Gorilla meat is popular with many Africans, so poaching is a problem, but the biggest threat is habitat destruction.
There are only a few tens of thousands of gorillas of all types left in the world, including a few hundred in zoos, almost all of which were bred in captivity, rather than captured in the wild.
It would be sad indeed if some day the only way to see any gorilla is in zoos like Toronto’s; sadder still if the day should come that the only gorillas we know are animated Disneyfied ones.
