Galapagos Finches in Trouble

According to a story in the Independent, by Mike McCarthy, the finches that Darwin wrote about in his book On the Origin of Species, are in danger of extinction. McCarthy writes:

There are now only about 100 individuals left of the Galapagos mangrove finch, the rarest of the 14 closely related finch species that Darwin encountered when he visited the islands in 1835 as the naturalist on board the survey ship HMS Beagle.

All of these species evolved from a single common ancestor to fit different niches in the ecosystem, and when Darwin realised this once he was back in Britain, it helped to trigger his insight that completely new species could come into being through the process of natural selection.

The mangrove finch has shown the most extreme evolution of all: it inhabits only the narrow strips of mangrove swamp that are found in just a few parts of the Galapagos coastline.

Black rats which infested the holds of pirate ships have been identified as the chief culprits behind the destruction of the finches. The rats are thought to have arrived on Isabella, the largest of the Galapagos islands, on pirate vessels perhaps as early as the 16th century. Pirates used the archipelago, which is around 500 miles off the coast of Ecuador in the Pacific Ocean, as a hiding place before sailing off to the Spanish shipping lanes in search of boats carrying treasure.

The conservation effort is underway to move some of the finches to a location that is free of predatory rats. The story also allows for some observations that only those steeped in "Darwiniana" would know:

When Charles Darwin visited the Galapagos Islands in 1835 he and colleagues collected many of the finches, but did not at first realise they were related and missed their significance. It was not until he had returned to London that the ornithologist John Gould examined them and found them to be all subtly different but closely related members of a quite new family of birds.

It was this discovery that set Darwin thinking that they may all have evolved from a single common ancestor, and thus to start to understand the mechanism of natural selection, which enabled new species to evolve.

I hope the project is successful.