ANIMAL ARMS RACE
Nature’s Wildest Weapons: Horns, Tusks and Antlers IPLAYER
Available until 18 May Animals are wild in tooth and claw – and in horn, tusk and antler. Presented by biologist Doug Emlen, this new Natural World film is a fascinating, fast-paced investigation into the biology of the animal arms race, revealing why the armouries of some species have become so extreme.
According to Doug, who has spent his life looking at appendages in the wild, there are three main explanations for weapon evolution, all of which revolve around reproduction: first, if you have a resource to defend (as does Darwin’s beetle of Chile, which uses its bodylengthsized mandibles to throw rivals off its feeding tree); second, if you experience intense competition over access to females (as do male elephants, which have just five days every four years to sire offspring); and third, if you settle your disputes by means of ritualised duels (as do Jackson’s chameleons, which lock horns in head-tohead combat).
Doug also introduces the animal with the greatest weapon of them all – the fiddler crab.