LITMIR.BIZ

      An elephant is big. Very big. A fully grown adult male can reach a shoulder height of 3.4 metres and weigh up to 7,000 kg. That’s the same as four family cars, with passengers. The largest known elephant was a male, shot in Angola in 1956, which was a colossal four metres tall, as big as some of the prehistoric species we mentioned, and is thought to have weighed 10 tonnes. And while there are other megaherbivores roaming the earth today – including four species of rhinoceroses, the common hippopotamus, and giraffes – none of them come close to the size of a full-grown African elephant.

      The elephant’s enormous size has been the key to their evolutionary success. It gives them a triple whammy of survival benefits: making them less vulnerable to predators; enabling them to live in a wide range of habitats; and meaning they can eat a wide range of foods. This allows elephants to move into different areas when there’s not much food around.

      All the same, there’s a big difference in size between male and female elephants, with females normally around one metre shorter than males, and topping out at around 3,000 kg.

      The difference in size between males and females all comes down to sex. It’s a common feature in many animal species, and is known as sexual dimorphism. In elephants, as with many mammals, the males don’t have much to do with raising their offspring. Their role ends basically at finding and then competing for receptive females with whom to mate. Male elephants aren’t particularly choosy when thinking about the size of their partners, either, and as long as the female is in oestrus (the time when they can get pregnant and so are ‘sexually receptive’), males will try to mate with them. That means there’s no selective pressure picking out larger females over time. The only thing limiting the number of offspring a male elephant can sire is the number of females he can find and mate with, which in theory could be in the hundreds.

      For females on the other hand, as is often the case, size does matter. Females put a lot of time and energy into raising their young, so they want to give each one the best chance of survival. This means they want the healthiest and strongest males to breed with, in order to ensure their offspring are more likely to be healthy.

      It takes twenty-two months of pregnancy for a female elephant to produce a newborn, which can weigh more than 100 kg at birth. The female spends the next few years nursing the youngster (known as a calf), until it can be persuaded to give up milk and survive solely on solid food – often only because the mother has had a new calf that needs her milk more. So, there is usually a gap of around four or five years between each new baby. This means a female elephant who typically gives birth to her first calf when she is between the ages of eleven to fourteen years, and who lives to sixty, might raise only nine or so calves over her lifetime.