Elephants and Ivory
An elephant's tusks are really incisor teeth which keep growing throughout the elephant's life, although general wear and occasional breaks can keep their size in check. They are made from layers of dentine (ivory) which is very hard. Male (bull) tusks tend to be larger than female (cow) tusks although it is possible to find tuskless members of both sexes.
Jonathan Kingdon's excellent "Field Guide to African Mammals" suggests that the length and versatility of the elephant's trunk enabled the elephant to evolve into a larger mammal, at the same time reducing the requirement of incisors for feeding functions. Their limbs lost functionality as they adapted towards bearing an elephant's great weight, leaving the head as the main focus for dealing with the environment. The trunk is used for retrieving food (drinking water, ripping vegetation, picking berries or rummaging the soil and undergrowth) and some gentler activities such as cleaning themselves. The tusks are used as weapons and general purpose tools.
Besides their tusks, elephants have single molars (a series of six which wear away in succession throughout their lifetime) for grinding the rough vegetation they eat.
The Ivory Trade
Both African and Asian elephants are under threat from poachers who kill them for their ivory tusks.
Although early poachers would only kill one or two elephants at a time this would still have had a big impact on the population, mainly because the poachers would kill the older male elephants for their larger tusks. Killing older elephants means that immature elephants are left to grow up without any parents to help them (young orphans may even die). Killing mostly male elephants means that there is a dangerous imbalance between the ratio of male to female elephants. Things are much worse now as modern poachers are more organised and have better weapons so that they can - and do - kill whole families at a time.
Fortunately today's world is more aware of the impact of ivory poaching and smuggling. An international five-year moratorium on ivory trading was agreed in 1989, the year when President Moi publically burned a large pile of ivory in Nairobi National Park under the direction of Kenya Wildlife Service's Dr Richard Leakey. More recent methods to track elephants and fight poaching involve 'fingerprinting' their footprints and ear patterns.
There is a debate whether ivory trading should be allowed in a controlled way or banned completely. One argument in favour of a controlled trade is lowering the black-market value of ivory. One argument against any trade is whether we should be making money from a scheme which could encourage more poaching.
Click here for a photograph of an elephant.
Jeremy Youngman 2000
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