Animal of the Week March 07, 2005 -- Vampire birds of Wolf Island

Happy Second Week of March guys,

This weeks animal of the week is Geospiza difficilis (sharp-beaked ground finch). This inocuous looking LBJ (a birders' classification that stands for little brown job) is notable for a couple of reasons. Geospiza may be familiar to you as the genus of finches found on the Galapagos Islands. As they arrived on the remote archipelago, various ecological roles were not occupied so the birds diverisfied to fill these roles and eventually became distinct species. Although this radiation is commonly said to have led Darwin to the theory of evolution by natural selection, it is not so. Darwin's collection of finch specimens was slapdash at best and the significance of all the similar looking LBJs occupying different niches on the Galapagos was not recognised until years later. An unlikely role occupied by Geospiza difficilis (from the ominously named Wolf Island [not Wolf Lake, that's a whole different mailout]), is that of vampire. These little birds climb onto the backs of nesting or resting boobies (like gannets), peck at the skin until the blood starts running, and lap up the resulting flow.
(image from: http://www.justbirds.org/Galapagos/Sharp-beaked%20ground-finch.htm)