GALAPAGOS LANDBIRDS

Were it not for the landbirds of the Galapagos, we might get a different picture of evolution. Specifically, were it not for the Galapagos finches, for these are the birds that so intrigued Darwin. You can learn more about how Darwin was inspired by these birds on the finches page (see below).

In conservation terms, the land birds are the most important of the Galapagos avifauna (= birdlife). Of the total twenty-nine species, twenty-two are endemic — found nowhere else. This is the opposite of the situation with seabirds. Why is this?

The difference in numbers of endemic species can be explained by the distance of the islands from the mainland. Most landbirds would have great difficulty making the 600 mile journey. Once there, they have to survive and reproduce, which means at least two birds, a male and female, would have to arrive around the same time and survive long enough to mate and raise young. However, once the intial hurdle is overcome the islands provide new opportunities. Where there are no pre-existing species, the new arrivals are free to evolve into available niches, as happened with the finches. So now there are thirteen species each descended from a single founding event. With the lack of predators flightlessness evolves, as it is energetically expensive to fly and birds that spend a lot of time in the air are likely to end up blown offshore.

There are so many fascinating examples of how life has responded to the Galapagos' unique conditions it is no wonder scientists call the islands a "natural laboratory."