The Galapagos Islands are renowned as a crucible for evolution. Famously, the ancestral finch species, following its arrival from South America, radiated and adapted to the varying environmental conditions available on the different islands. Fourteen species are now found through the archipelago.
On Santa Cruz, where I started my Galapagos journey, these birds are small, common and friendly.
Santa Cruz was large, wet and forested. Wolf Island, in the far north of the archipelago, is a very different place. Wolf lies 140 km north of the main islands, created by a different volcanic system. It is tiny, less than 3 km2 in size. The island is closed to visitors and rarely visited even by park staff or scientists: the first landing was in 1964, with the aid of a helicopter.
On this remote volcano, these cute little birds have changed. These finches have evolved. These finches… are vampires.
Introducing the vampire finch
I know, I know, vampires are so 2008. These little bloodsuckers have been around somewhat longer. They are a subspecies of the sharp-beaked ground finch, found on several islands. On Wolf, a lack of natural water sources mean the island is extremely dry for most of the year. The best source of fluid available? Blood.
Nazca boobies nest in abundance on the island, their permanently quizzical countenance greeting us in the hundreds upon arrival. The finches flit among them, occasionally landing on their folded wings, whereupon they use their sharp beak to find and pull out a developing feather.
The blood flows freely from the wound, staining the boobies’ white plumage. Multiple finches were sometimes taking turns to lap it up.
Although it looks macabre, to put it lightly, the boobies did not seem overly troubled. In fact, they barely seemed to notice the finches. This blood-drinking behaviour is thought to have evolved from the finches pecking out parasites, so perhaps the boobies haven’t worked out that the finches have changed the arrangement. Poor boobies.
All in all, an interesting afternoon. The harsh terrestrial environment of the Galapagos has led to some fascinating adaptations among the animals that call it home.
Jonathan and myself hugely appreciate the Galapagos National Park authorities granting us a permit to land on Wolf.
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I write a few articles just for my mailing list. They normally focus on something interesting, and possibly hilarious, that I've learnt about sharks (or other random animals) that week. There may also be groan-inducing jokes.
Real talk: there will be groan-inducing jokes.