Somehow, many millions of years ago, a finch arrived on the Galapagos Islands. Did it float on a raft of greenery and logs from the mainland? This was long before a boat would have carried it across the thousand miles from the South America mainland.
The finch spread to the other islands of the Galapagos over time. To survive on each island, the finch adapted over many generations to the conditions, particularly the food sources that were available. Charles Darwin’s theory of evolution was based in large part on the finches he observed on the Galapagos Islands.
In a handy guidebook that we took along, “Birds, Mammals, and Reptiles of the Galapagos Islands” by Andy Swash and Rob Still, photos of the finches were spread out over 4 pages, and they looked a lot alike – except for their beaks. There are 13 Darwin finches currently on the islands and 13 different beaks.
The authors, and our guides, warned of great problems in identifying many of these birds. Still, it would be interesting to see how far we could get in trying to identify the finches we were able to photograph. The photos were not always very good, but we hoped good enough for our identification purposes. To guide novice birdwatchers (like us), a chart in the guidebook showed a profile of all the finches’ bills to help with identification.
Santa Cruz Island is home to 9 species of Darwin finches. That makes it much more difficult to identify the birds we saw there. 3 of those species are uncommon, so we assumed that we could concentrate on the other 6.
The Darwin finches are only found on the Galapagos Islands. They continue to change over time and continue to be a source of curiosity and wonder to all who see them.
One last note: In reading about the Darwin finches, it has been determined that they are not really “true finches” after all. Their closest relative in the bird family is a tanager. Who knew?