How the eggshell got its spots
COLLECTING wild birds’ eggs is a hobby, once popular, that is frowned on today. In some countries, it is illegal. That, though, makes past collections the more valuable. And one of them, assembled by the splendidly named John Colebrook-Robjent and bequeathed by him, in 2008, to the Natural History Museum’s outpost at Tring, north-west of London, has recently been pressed into service. Its job was to answer questions about the arms races that go on between some birds and the nest parasites (cuckoos and so forth) that attempt to trick them into raising the parasites’ young.
That this behaviour causes parasites’ eggs to evolve to look like those of their hosts, and the hosts’ eggs to evolve not to look like those of parasites, is well established. But Eleanor Caves of Cambridge University and her colleagues wondered if there was more to it. They noted that some nest parasites have sub-groups, known as races, which specialise on different…Continue reading
Source: Economist