Andrew Sugden

In October 2000, the last wild Spix’s macaw, a solitary male, disappeared from its patch of forest in Brazil. The species is not, technically, extinct: a few dozen individual birds survive in zoos and in the aviaries of private collectors, but it is now in the realm of the undead, where it will remain until either the last individual dies or – less likely – the species is...

In 1984, a small patch, no more than a metre square, of the tropical alga Caulerpa taxifolia was discovered in the Mediterranean – where it had never been seen before – growing on the sea-bed immediately below the Oceanographic Museum of Monaco, then under Jacques Cousteau’s directorship. Five years later, the area of the patch had extended to a hectare. In July 1990, another colony of the same alga appeared at Cap Martin in France, 5 kilometres to the east, and in September of the same year it was found near Toulon, 150 kilometres to the west. In 1992, patches were discovered in the Balearics. By the following year, Caulerpa had spread to Italy, as far as the whirlpool of Scylla and Charybdis, and in 1994 it turned up in the coastal waters of Croatia. By the end of 1996, the alga had invaded and occupied 70 sites on the northern Mediterranean coast, spreading over a total area of more than thirty square kilometres and to a depth of more than a hundred metres.

The lengths to which people have gone to eradicate snakes are remarkable. A century ago, for example, a prolonged campaign was mounted against timber rattlesnakes in the north-eastern United States. Since this species tends to aggregate in large numbers in winter dens, eliminating them seemed quite feasible: the dens were variously dynamited and cemented over and timber rattlers have now disappeared from most of New England. Yet feelings run so high that in 1979 an employee of the US Office for Endangered Species was fired by the Secretary for the Interior for protesting against the presence of timber rattler meat on the menu of a Washington restaurant. Snake populations are almost everywhere in decline – which is why Harry Greene has set out to improve their image and enhance their appeal.