I promised to write to you about Vervet Monkeys and how they outwit Leopards. This is a photo of a Vervet setting out on another candy-bar raid at our hotel in the Serengeti.
Vervets always live in groups. When you see one, you know that there are a bunch of others nearby. Being in a group has many advantages for various kinds of mammals. For example, when Lee and I go bird-watching, we like to be with a few other people, because that means there are more eyes to look for the birds. Anyone who spots a good bird will instantly alert the others.
For Vervets, living in a group means greater safety. There are more eyes and ears and noses constantly alert for danger.
The Vervets have three main enemies: snakes, eagles, and leopards, all of which love to eat Vervets.
Vervet Monkey
Seronera Lodge
(Click on any photo to enlarge it)
Here's one of those enemies, a very large leopard.
As you will have seen in the first photo, Vervets are quite small monkeys, which means that they have small brains. However, their brains are large in comparison with those of non-primate mammals of the same size, so they are intelligent for their size. Their intelligence allows them to have the bare beginnings of language. In particular, they have different calls, different "words", for their three great enemies, a snake warning call, an eagle warning call, and a leopard warning call. By giving a specific warning call, a Vervet alerts the other members of its group not only that there is danger but also what kind of danger it is. (In one paper I read, the researcher reported seeing a mother Vervet smack her kid who had given the leopard warning call when the actual danger was an eagle; it's dangerous of course to tell the group to be looking on the ground for a leopard when the real peril is an eagle coming from the sky.)
Interestingly, other animals of the savannah have learned to recognize these warning calls given by the Vervets and to respond appropriately when the Vervets begin shouting that there is, say, a leopard in the vicinity. People can also learn to understand these calls.
One morning when we were driving about in the Serengeti, we saw a Vervet standing at the very tip-top of a large tree giving the leopard warning call. Since we very much wanted to see a leopard, we stopped and spent about 20 minutes looking for the leopard. All the while, the Vervet continued to call loudly, but we were unable to spot the leopard ourselves, probably because the grass was very tall. So, disappointed, we drove on.
Leopard
Serengeti
We came back an hour or so later, however, and there was a leopard in that very same tree.
It was lying on the branch quite relaxed with its legs hanging down. We suspect that it had killed something and hauled it up into the tree to keep it away from scavengers. We weren't worried about the monkey who'd called the warnings, however, because a leopard can't catch a healthy monkey who knows where it is.
Leopard
Serengeti
