More than just big ears

To the non-specialist, large ears in elephants used to mean African, small ears, Indian. But to taxonomists African elephants have long posed a more complex puzzle. During the nineteenth century, it was fashionable for wealthy trophy hunters to assign their own names to species they had shot destined for the museums of Europe. At least 18 elephant subspecies were claimed following this fashion. But more recently, taxonomists have been building a stronger case that the African elephant may comprise more than one species. As in many other studies, molecular data have now been gathered to examine population and species relationships on the back of differences in morphological characteristics: forest elephants in central Africa are significantly smaller, have longer, thinner and straighter tusks and smaller ears than their savannah counterparts. These differences have led to suggestions that they may be different species. But the relationship of the savannah and forest elephants of western Africa to the others has been more difficult to determine because of the difficulty of obtaining DNA samples from animals in dense, remote forest. But a new study Soc B, published online) uses new techniques for extracting DNA samples from faeces to help study the western elephants. They have looked at sequences in the mitochondrial cytochrome b control regions, along with those from four microsatellite loci for comparison with material from other elephant populations. Their studies suggest that western forest and savannah elephants may be a distinct species from the two proposed central and eastern counterparts. They also believe that historical separations may have been the result of dramatic climatic changes on the continent forcing populations apart. The researchers therefore believe the African elephants may hold a trace of some of the climatic calamities that occurred on the continent over the 5–6 million years of their evolution. These clues may also offer important input to conservation management planning of remaining stocks in the face of both human and climatic changes that are reducing and fragmenting their ranges. Numbers are estimated to have declined across the continent by a half to two-thirds of their population of around 1.3 million in 1979. And if three species are confirmed, especially as the western forest elephants are particularly vulnerable to human exploitation, a major rethink in conservation strategy may be required. Relationship puzzles: The populations of African elephants may actually comprise three different species according to recent research. Such results may force …