Insight: Birds of the Galápagos

From the marbled godwit to the black-necked stilt, the birdlife on the Galápagos Islands, which taught us about evolution, is still rich, rare, and rewarding.

Where else in the world will birds practically come out to greet you? Life without predators has made the birds of the Galápagos fearless, which means that many of them are easy to spot. There are 58 resident species, of which 28 are endemic, as well as about 30 migratory birds. The seabirds are the most frequently seen: in the dry coastal areas you are likely to spot three species of the booby family, the waved albatross – found nowhere in the world except on the Galápagos island of Española, which supports a nesting colony of 12,000 pairs – and the world’s only flightless seabirds, the Galápagos penguin and the flightless cormorant. The best time for bird-watching is in winter (October to February) when most migrants are visiting, and birds are reproducing. Then, a serious ornithologist might see 50 species in a week, and even a dilettante should be able to spot two dozen.

There are dangers in paradise, however: the introduction of mainland animals brought over by economic migrants to the islands has been disastrous. Cats and rats prey on the birds, while goats destroy the birds’ habitats. Farming on the inhabited islands also destroys habitats (agriculture supports 20 percent of the locals), and a natural phenomenon, the El Niño current, brings mosquito-carried disease and disrupts the food chain.

The magnificent frigate bird (Fregata magnificens magnificens) and its close relation the great frigate bird, can be seen near the coasts of many islands. The male is remarkable for the red gular pouch which puffs in the mating season.

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The Secret of Darwin’s Finches

The finches of the Galápagos were vitally important in the development of Charles Darwin’s ideas about evolution and the formation of species. When he set off on his voyage around the world on HMS Beagle (1831–6), he believed, like most people of his time, in the fixity of species. But on the Galápagos he observed that 13 different species of the finch had evolved from a single ancestral group, and it was this (together with his observations of the islands’ tortoises) which led to his contention that species could evolve over time, with those most suited to their natural environment surviving and passing on their characteristics to the next generation.

The main differences he noted between the finches was the size and shape of their beaks, leading him to conclude that the birds that survived were those whose beaks enabled them to eat the available food.

The 13 species of finch are divided into two groups: ground finches and tree finches, of which the mangrove finch, found only in the swamps of Isabela Island, is the most rare. You are unlikely to see all of them on a short visit, but it’s a challenge to see how many you can spot.