As soon as the klaxon-voiced park guide announced that the parrots hated loud noise and would flee at a raised decibel I knew any sighting would be unlikely. Plants have a higher noise tolerance, though, and she started to bellow out a series of startling facts: each Coco de Mer nut needs a licence to export; it is illegal to taste them; every palm and nut belongs to the government, just as all unmarked mute swans in the UK belong to the Queen; each nut is worth some £250 and so on. In the manner of a fearless sex education teacher she also pointed out that the plants are either male or female and the male, in one of nature's better gags, has an unmistakable and impressive appendage that perfectly complements the allure of the female's nut.