Not just the ears
February 7, 2018
Elephants are fascinating creatures. They are Earth's biggest land animals but their closest land-dwelling relatives are hyraxes, furry little creatures that look more like marmots and are smaller than your average house cat.
As children, we learn that there are African elephants and Asian elephants and that you can tell them apart simply by looking at their ears. The African varieties have bigger ears than their Asian counterparts.
What we often don't learn at school, however, is that there exist many more differences between the two kinds of pachyderms.
How many species?
To be exact, there are in fact three and not two species of elephant. Two live in Africa and one lives in Asia.
Initially, the African forest elephant (Loxodonta cyclotis) was considered a subspecies of the bigger and better known African bush elephant (Loxodonta africana). Genetic testing confirmed in 2010 that the two are actually distinct, with the forest elephant being more closely related to the extinct European straight-tusked elephant (Palaeoloxodon antiquus) than its well known savannah-dwelling cousin. For their part, Asian elephants can be broken down into three subspecies.
Ear today
But before things get too confusing, let's return to the question of ears.
For elephants, these organs aren't just useful for hearing nor are they merely elaborate fly swatters. They are essential for the creature's survival.
That's because the giant animals lack an ability that we take for granted (even if we sometimes find it icky): They cannot sweat. So how do they keep their body temperatures down in the blazing tropical sun? Firstly, they might try to cool off in the water and, when that's not an option, they use their ears.
These large flaps contain many blood vessels, which allow them to act as heat exchangers. As the blood flows through the ears, just below the skin, it cools, thus lowering the elephant's temperature.
How many fingers?
All elephants have the characteristic long trunk, which they use for everything from breathing and drinking to dusting, washing, making sounds and even fighting. The trunk contains tens of thousands of distinct muscles that allow the animals to lift items weighing hundreds of kilos.
At the same time, elephant trunks are more sensitive than human fingers. The finger-like extensions at the end of each trunk can perform very delicate tasks like cracking a peanut shell without breaking the seed inside. All that holds true for the three elephant species, but there is one notable difference. African elephants have two such extensions at the tip of their trunks, while the Asian species has only one.
There are other subtle anatomical differences beyond size too. For instance, African elephants have 21 pairs of ribs, whereas Asian elephants have 19 or 20 pairs.
It's all about the tusks
Perhaps the most obvious difference between African and Asian elephants — besides the ears — lies in their tusks. These pointy, prominent second incisors in the animal's upper jaws are one of the main reasons they are hunted and killed by humans.
Elephants on both continents have tusks. But female Asian elephants tend to have either very small ones or none at all. And just as humans are left- or right-handed, elephants are left- or right-tusked. Usually it's easy to spot, which one is the dominant tusk. It's the one that's more worn down from constant use.