It is only a very wise man or a fool who thinks he is able to identify all the finches which he sees. This quote from Michael Harris' field guide to the birds of Galapagos has been the source of comfort to countless new Galapagos naturalists. One of the greater challenges of someone starting off here is to tell one of these small sparrow-sized birds with relatively drab plumage from the other. These similarities are just superficial though, as the range of different beak structures and feeding habits is truly phenomenal considering their relatively recent evolution from a common ancestor. Some of these birds eat seeds, some eat leaves, some insects, some remove parasites from the resident reptiles, some drink blood from seabirds and there are even two that use a tool to dig out grubs from branches (two of only three tool-using birds in the world!).

According to author Michael Jackson (Galapagos: A Natural History), the finches in the archipelago fill the roles of seven different families of South American mainland birds! This makes this fascinating group of birds a textbook example of the theory of evolution by natural selection. They thus earned the name of Darwin's finches, although he never realized the importance of this group of birds until it was pointed out to him much later by John Gould, the man who worked on all the birds Darwin collected during the voyage of the Beagle.

Because of a slight change in our itinerary, we were able to visit Santa Cruz Island a day earlier than planned. This is the second largest island in Galapagos, and thus harbors a large percentage of the finch species, ten of them in fact. During our walks in the highlands, we were able to spot several of them, and watch some of their behaviour. The bird in the picture is the medium-beaked ground finch (Geospiza fortis) preening its feathers in an endemic tree, the cat's claw (Zanthoxylum fagara). This small evergreen tree dominates the fifth vegetation zone of Santa Cruz, known as the Zanthoxylum Zone or Brown Zone, because of the abundant epiphytes that crowd the tree limbs.