Vegetarian Tree Finch

Tweet of the Day is the voice of birds and our relationship with them, from around the world. Chris Packham presents the vegetarian tree finch on the Galapagos Islands. These streaky sparrow-like birds found on the Galapagos Islands may look rather plain, but belong to the evolutionary elite, having attracted the attention of Charles Darwin on his visit there in 1835. Darwin noticed that the fourteen or so species of finches, which he concluded were derived from a common ancestor on this isolate archipelago, had evolved bills adapted to the type of food available. The Vegetarian finch has a bill rather like a parrot's, with thick curved mandibles and a biting tip which also allows it to manipulate seeds, similar to a parrot or budgie. Vegetarian finches are especially fond of the sugar-rich twigs of certain shrubs and are use the biting tip of their bills to strip off the bark to reach the softer sweeter tissues beneath: a niche that other finches on Galapagos haven't exploited yet.

Producer : Andrew Dawes