Elephants evolve smaller tusks

Evolution is helping elephants to fight back against poachers - more of these giant animals are now being born with smaller tusks because hunting for ivory is reducing the gene pool. According to a study by a joint team of researchers from Oxford University and British conservation charity Save the Elephants, poaching of large male elephants for ivory has changed the natural breeding behaviour of these animals. In fact, hunting is allowing smaller ones with shorter tusks to produce more calves and over time, the average tusk size has been decreasing.

The average tusk size of African elephants has halved since the mid-19th century, according to the new study, which has also found a similar effect in India's Asian elephant population. African elephants are larger and have longer tusks than their Asian relations. In males, tusks are often used to intimidate other males, and sometimes in fighting for mates. Those with the biggest tusks are usually the most successful. However, the ivory of large African elephants is particularly prized by hunters and traders for its quality and this has seen hundreds of thousands of animals killed. It is estimated that there were 1.2 million African elephants in the late 1970s, but there are now fewer than 500,000.