protect the group

W: Right. You’re talking about social groupings here, could you tell us something about the ways animals form into groups?
M:Yes, er many, many animals are very solitary animals; the only times they get together is when they mate, or when they’re bringing up their young. The majority of animals are solitary, but a very significant group of mammals and insects, like ants and termites, bees and wasps, are very social and they group together because in a group it’s much safer-you can defend yourself more easily if you’re in a group, you can find mates more easily if you’re in a group, and you can change the world around you by working with the others if you live in a group. Solitary animals have a much more difficult time in many ways.
W:You mentioned lions and other carnivora earlier on. Do they group very much?
M:Yes. Most cats in fact don’t group. Er, lions and, to a lesser extent, cheetahs are the only cats that group together-a group of lions is called a pride-and you might get anything up to fifteen or twenty lions in a pride. A pride of lions would have perhaps two or three males, perhaps a dozen females, and then the cubs. But the real lion group consists of females with their cubs. The males tend to stay for a few years and then they get kicked out by a group of younger males that comes in and take over.
W:Right. What about other animals such as the. .. you’ve got here zebras, for example, and the apes as well, do they. . .
M:Yes. Well, zebras form temporary groups. Most of the year they’re basically on their own, although you will get groups of mothers looking after their foals, but at one time a year, when the females are ready to mate, then the males move in, and the males fight one another very vigorously: they will try and bite each other, they will try and neck-butt each other and the biggest, strongest males see off the others, and they’re the ones that collect a little group of females around them and mate with those females. But once mating is finished, and the babies are beginning to develop inside the mothers’ bodies, then off the males go and live solitary lives again for the rest of the year.
W:And how about the apes?
M:Ah, well, now your’re talking about the group of animals that we belong to, and apes-some apes-live in very, very big and complicated social groups. Not all-orangutans, for example, big apes that live in Indonesia and Malaysia-they’re very solitary and one adult may meet another adult only once every two or three years, when a male and a female mate, and then, the only relationship then will be between a mother and her baby. The baby will stay with the mother for two or three years, four years, five years even, learning from the mother, learning what sorts of foods to eat, what the signs of danger are, and then when the baby grows up, off it’ll go, and live its own, solitary life. The reason why orangutans are solitary is because there’s not very much food in a forest and if there was a big group of orangutans all the food would just run out. But, leaving Asia and going to Africa, then you find very social apes. Now, gorillas, for example, gorillas live in unimate groups.
They used to be called harems but the technical term is unimate because there’s one male within the group;one male, and then around him will be anything up to six, seven, eight, nine females, plus all the babies. And that one male in the group is the silverback gorilla, and he’s much bigger and stronger than the others. He’s got silvery fur on his back and the others won’t challenge him and he’ll lead the group slowly through the forest, settling down every night and moving on the next day, finding food. So that’s a unimate group, but if you move a little bit further west, into West Africa, you’ll start to come across chimpanzees. Now they’re a bit smaller than gorillas;they spend a lot of time in the trees, whereas gorillas are down on the ground, and chimpanzees are much more closely related to us than they are to gorillas. They’re our closest living relatives. Now chimps live in multimate groups;in other words you’ll get, oh, anything up to six, seven, eight males, then you’ll get two or three times that number of females, a dozen, two dozen females, plus all the youngsters, so we’re talking about groups that can be as big as forty or fifty or even sixty. Now, a chimpanzee group-multimate group-is a very flexible type of group: it constantly splits into smaller groups, off they go for a few days, back they come, reform, break up again and within that group the males tend to hang around the outside, protecting the group, fighting off rival males that might want to come in and mate with the females, but they tend to come and go to some extent. The on-going core of the chimpanzee group consists of females with their young, and sometimes sisters will actually work together to bring up their young collectively. Yes, so apes are very, very social animals indeed.