The tusks of an elephant are actually protruding teeth (upper second incisors), and go further back into the head and connect to the skull. They are also, sadly, one of the main reasons that the elephant has been hunted and killed by humans, since the ivory is good for carving. Two thirds of the tusk have pulp cavities, nerves and blood vessels, meaning that a tusk breaking can lead to great pain, and even death for the elephant.
Uses of the tusk
The elephant uses its tusks for digging, stripping bark, and to move large obstacles, such as logs, out of the way. They also make tremendous weapons when fighting each other, or against any predators brave enough to take them on. Elephants prefer to use one tusk over the other, just like being right or left handed in humans. This “master tusk”, because of repeated preferential use, will be more worn down and rounded at the tip than the other.
Tusk size and differences
While all African elephants have tusks (both male and female), only some Asian elephants do, and the females have much shorter ones that are hidden under their lip. The size of the tusks of both species has been found to be decreasing, sometimes by as much as half of what they used to be. This could be due to genetic pressure against large tusk size, since ivory hunting has led to fewer males with large tusks, enabling the males with smaller ones (who would lose dominance battles otherwise) to breed.