THE GALAPAGOS FINCH
Darwin’s Finches (also known as Galapagos Finches) may not be the most eye-catching birds that you see at the Galapagos Islands. In truth they are not colorful, they are not big in size, and are rather plain looking. But what the Galapagos Finch lacks in beauty, it more than makes up for in importance to the natural world.
Galapagos Finches are one of the truly iconic birds of the Galapagos Islands. That’s all thanks to the work of one man – Charles Darwin. These little birds played a surprising role in his ground breaking Theory of Evolution, we’ll tell you all about that below. Today, Darwin’s Finches give visitors a rare, first-hand view of evolution in action. An eye-opening moment of understanding into the complex workings of nature.
For many Galapagos visitors, Darwin Finches may even be the very first species that you encounter. They often flit around airport arrivals, searching for crums to eat, or friendly visitors who can spare a morsel. This is where their charm lies, they are friendly little fellas, and they have an amazing story to tell.
So, let’s dive right in. Keep reading for everything you need to know about the humble Darwin Finch. Why are Galapagos finches famous? What does Charles Darwin have to do with it all? Which Galapagos Finch species exist today? and where you can see them?
Charles Darwin & Galapagos Finches
In 1835, the Beagle Ship brought English botanist Charles Darwin to the Galapagos Islands, where he found a species of bird that would shape natural history forever – the Galapagos Finch.
At first Darwin did not appreciate the significance of the Finches, he was content to simply collect samples and continue on his voyage. It was not until his return to England that it dawned on him that he had taken home various different, but related, species of Finch. This led him to the realization that:
“Seeing this gradation and diversity of structure in one small, intimately related group of birds, one might really fancy that from an original paucity of birds in this archipelago, one species had been taken and modified for different ends.”
From these observations Darwin’s famous Theory of Evolution was born. Human knowledge was changed forever, and the Galapagos Finch was renamed the Darwin Finch in his honor.
So, let’s delve deeper into the history of the Darwin Finch – What is the bird’s origin? and How did they evolve?
Darwin’s Finches Evolution
How did the Galapagos Finch evolve? Scientists believe that Darwin’s Finches are descended from the Grassquit. This bird species is still found today on mainland South America, including in Ecuador.
Over 2 million years ago the small Grassquit made an epic journey of more than 1000Km across the seas. Perhaps through flight, or more likely a combination of flight and rest on foliage drifting on the sea currents. Miraculously, the Grassquit somehow found it’s way to the small volcanic islands of the Galapagos Archipelago, far into the Pacific Ocean.
Grassquits in fact migrated to various different islands at Galapagos. Let’s take a simple example to illustrate the point. Suppose that we have two seperate populations of Grassquit, each arrive onto different islands. Each island has distinct food sources and habitat. On one island the birds can feed easily on seeds from abundant plants, while on the other island cactuses are the common food source.
It is here that the story starts to get more interesting. Natural Selection comes into play. On the first island, a short, stout beak was beneficial for eating seeds from the ground. So birds with this beak type were more likely to survive, mate, and pass the short beak trait onto their chicks. On the second island, a longer pointed beak was more useful to pierce cactus fruit. Likewise this pointy beak trait meant a higher chance of survival, and was passing genetically onto their chicks.
Now let’s fast forward over hundreds of thousands of breeding generations. The advantageous beak traits on each island have been passed down to young birds many thousands of times. So over a long period of time, the size and shape of bird beaks between the two islands has become significally different. The birds on each island are now sufficiently different in appearance and behavior that they can be recognised as seperate species. Not only that, they are also now both different from the original pioneering Grasquit. So the same bird species that arrived to Galapagos has now evolved into two different, unique species.
Finally, imagine that Grassquits arrived to many different islands. Now we have many new different bird species that have evolved from the one original bird. The diagram below gives a clearer idea of the different beaks that each Darwin Finch species has developed.
In fact, today Galapagos Finches can be differentiated not only by beak size and shape, but also by body size, song and feeding behaviour.
As such, Darwin Finches are an exceptional example of the process of evolution of species. Back in the day, this was a very controversial discovery, that went against the widely accepted belief of god as the one creator. Extrapolating this theory of evolution further, Darwin was able to theorise that long ago man had also evolved from apes. At Galapagos you can also find other amazing species that have evolved due to their unique home on different islands. Check out the iconic Giant Tortoises whose shell shape differs according to food sources. Also the Flightless Cormorant that now has tiny wings and has lost it’s ability to fly. The Marine Iguana is another great example – the only iguana in the world to have learnt how to swim.
How to see Galapagos Finches?
The good news is that Darwin’s Finches are a common sighting on any vacation to the Galapagos Islands. Finches are land birds, and can be spotted year round. On either a Galapagos Cruise or Galapagos Land Tour you will undoubtedly come face to beak with more finches than you imagine, often at close quarters as their curiosity gets the better of them.
Contact us for a FREE GALAPAGOS TOUR QUOTE, to plan your perfect Galapagos vacation to see Darwin’s Finches with your own eyes.
Your naturalist guide will be happy to point them out to you, and explain the adaptations made by each finch species over the years. It is often not easy to correctly identify between species as plumage is very similar. Instead try looking for differences in habitat, size and beak shape, and don’t forget to take a beak chart with you to help with identification. See how many of the 13 species you can tick off.
The 13 Species of Darwin’s Finch at Galapagos
Today there are more than 500,000 individual Darwin Finches living at the Archipelago. They are divided across 13 different Finch species, all endemic to the Galapagos Islands, meaning that you can only find them here, and nowhere else on earth.
So, let’s learn a little more about each Galapagos Finch Species, and where you can find each one. What are the 13 species of finches?
1. Common Cactus Finch
Conservation Status: Least Concern
Scientific Name: Geospiza scandens
Can be seen on: Santa Cruz, San Cristobal, Isabela, Floreana, Santa Fe, Santiago, Genovesa, Rabida, North Seymour, Pinta, Daphne
The Common Cactus Finch was originally mis-identified by Charles Darwin as a blackbird. Its beak is long, sharp, and pointed, enabling the bird to forage for food from Opuntia Cacti plants – nectar and pollen when in flower, or buds and seeds seeds, our of season, also eating caterpillars, and budworms. Like other finches, the males are black from beak to tail, and the females are grey with striped plumage.
2. Large Cactus Finch
Conservation Status: Least Concern
Scientific Name: Geospiza conirostris
Can be seen on: Española
Found only on Española Island, the aptly named Large Cactus Finch uses it’s long, sharp, pointed beak to feed on Opuntia Cactus nectar, buds and seeds, as well as insects. Males have black plumage, while females sport grey feathers with streaks. Mating season takes place when the rains come between December and June.
3. Sharp-beaked Ground Finch (or Vampire Finch)
Conservation Status: Least Concern
Scientific Name: Geospiza difficilis
Can be seen on: Fernandina, Pinta, Darwin, Wolf
The wonderfully named Vampire Finch gets it’s nickname from feeding habits which include sucking the blood of large sea birds. Although typically a seed-eater, the Sharp-Beaked Ground Finch also eats seabird eggs and cactus nectar. Most commonly found on Fernandina and Pinta Islands, this species of finch has become extinct in other parts of Galapagos.
4. Small Ground Finch
Conservation Status: Least Concern
Scientific Name: Geospiza fuliginosa
Can be seen on: Santa Cruz, San Cristobal, Isabela, Fernandina, Floreana, Española, Santa Fe, Santiago, Rabida, North Seymour, Pinta, Daphne, Marchena
The Small Ground Finch is one of the most common species found at the Galapagos Islands – often you will find them in towns – and it is also the smallest. Their small beaks are perfect for picking up seeds from the ground, and they aso enjoy eating bugs – often seen sitting on the backs of Giant Tortoise, waiting for bugs to land. The males are all black, and females are brown with streaked plumage. Like other ground finches, Small Ground Finches mate during the rainy season, when the foliage of the islands blooms, producing enough food to sustain young chicks and fledglings.
5. Medium Ground Finch
Conservation Status: Least Concern
Scientific Name: Geospiza fortis
Can be seen on: Santa Cruz, San Cristobal, Isabela, Fernandina, Floreana, Santa Fe, Santiago, Rabida, North Seymour, Pinta, Daphne, Marchena
Found on most Galapagos islands, the Medium Ground Finch’s adaptability has impressed scientists and naturalists during recent studies – within the species, Medium Ground Finches have both small and large beaks. On Daphne Major, the finches developed smaller beaks after a strong El Nino event, when an abundance of seeds were the primary food supply. Like the large ground finch, the male medium ground finch is black, and the female is mainly a non-descript dull gray.
6. Large Ground Finch
Conservation Status: Least Concern
Scientific Name: Geospiza magnirostris
Can be seen on: Santa Cruz, Isabela, Fernandina, Santiago, Genovesa, Rabida, Pinta, Pinzon, Daphne, Marchena
The Large Ground Finch is the largest of the thirteen Galapagos species, and also has the largest beak, which it uses to good effect cracking open nuts. The male’s feathers are black from beak to foot, while the female large ground finch’s plumage is brown with streaks. The birds mate for life, with the nesting season taking place between December and June when food supplies are abundant.
7. Small Tree Finch
Conservation Status: Least Concern
Scientific Name: Geospiza parvula
Can be seen on: Santa Cruz, San Cristobal, Isabela, Fernandina, Floreana, Santa Fe, Santiago, Rabida, North Seymour, Pinzon, Daphne
The miniature, curved beak of the Small Tree Finch distinguishes it from the other 13 species in the group, and makes the perfect tool to catch and eat insects. This Finch also feeds on seeds, fruit, and nectar, where males have black hoods and grey feathers, while females have browner feathers that are streaked.
8. Medium Tree Finch
Conservation Status: Critically Endangered
Scientific Name: Geospiza pauper
Can be seen on: Floreana
The Medium Tree Finch can only be found in the Scalesia forests of Floreana Highlands, and is on the critically endangered list due to the impact of the Philornis Downsi parasitic fly. The fly’s larvae feed on the finch nestlings to such an extent that scientific studies suggest only 6% of active nests are able to produce fledglings. The Medium Tree Finch has a curved, gripping beak that helps the greyish-brown and yellow bird feed on insects, seeds, and nectar.
9. Large Tree Finch
Conservation Status: Vulnerable
Scientific Name: Geospiza psittacula
Can be seen on: Santa Cruz, Isabela, Fernandina, Santa Fe, Santiago, Rabida, Pinta, Marchena
Identified by its four-note song, faded green plumage, and black hood and breast, the Large Tree Finch’s has a larger beak than the two other Tree Finches, resembling that of a parrot. This finch species eats insects, caterpillars, spiders, seeds, and nectar, breeding between December and June, with eggs that hatch quickly, and chicks that fledge within two weeks of hatching.
10. Woodpecker Finch
Conservation Status: Vulnerable
Scientific Name: Geospiza pallida
Can be seen on: Santa Cruz, San Cristobal, Isabela, Santiago
Found in both highland Scalesia forests and lowland arid zones the Woodpecker Finch is one of the most innovative birds of the species. They use small twigs and cactus spines to dig into crevasses and cracks in trees, forcing insects and spiders out into the open, and even use their long beaks to sharpen more appropriate tools for the job.
11. Mangrove Finch
Conservation Status: Critically Endangered
Scientific Name: Geospiza heliobates
Can be seen on: Isabela
Mangrove Finches are extremely rare to see, found only in two small areas of mangrove forest on Isabela Island, and critically endangered due to breeding problems in these small populations. Mangrove Finches eat insects, with their thin and downward curving beaks able to penetrate tree bark to forage for food. The Charles Darwin Foundation is actively involved in trying to invigorate the Mangrove finch population. The station scientists collect eggs from nests on Isabela, to hatch them in incubators, and raise the chicks safety until they are ready for release back into the Isabela wild.
12. Grey Warbler Finch
Conservation Status: Least Concern
Scientific Name: Certhidea fusca
Can be seen on: San Cristobal, Floreana, Española, Santa Fe, Genovesa, Pinta, Marchena
Named because of its uncanny resemblance to the Warbler Species, there are two types of Warbler Finches at Galapagos – grey and green. The Grey Warbler Finch lives on the outlying islands of the archipelago, found in shrubland and dry forest of arid zones. Warbler Fnches have a slender beak that they use to pierce tree bark in search of insects and spiders. Both Warbler Finch species high pitched, repetitive calls, repeated in quick succession.
13. Green Warbler Finch
Conservation Status: Vulnerable
Scientific Name: Certhidea olivacea
Can be seen on: Santa Cruz, Isabela, Fernandina, Floreana, Española, Genovesa, Santiago, North Seymour, Rabida, Pinzon
Originally thought to be the same species as Grey Warbler Finches, the Green Warbler Finch was identified as a seperate species in 2008, with subtle differences in habitat, appearance and song call. This finch lives in the central islands of the Galapagos, in regions where Scalesia forests grow, and is often spotted around the Twin Craters (Los Gemelos) on Santa Cruz Island.
Conservation of Darwin’s Finches
Darwin’s finches are under threat from a range of issues including introduced predators and diseases, habitat destruction and the invasive parasitic fly Philornis downsi. Fortunately work is underway to protect them – read on for information about a couple of examples.
Today, the Mangrove Finch is on the verge of extinction in the Galapagos, with only around 100 left, and as few as 20 breeding pairs. To keep these finches from disappearing altogether, the Charles Darwin Research Station and San Diego Zoo have partnered together in a captive breeding program.
The biggest threat to the Mangrove Finch is the parasitic Philornis downsi fly-larvae, which causes high mortality rates among offspring. During four months of caring for the chicks, the project team help them to develop the skills necessary for survival in the wild. Once they are capable of feeding themselves, they are transferred to pre-release aviaries in the Isabela mangrove forests, where they have 4-6 weeks to adapt to their new habitat, and then the aviary is left open so finches can leave of their own accord. The birds are fitted with miniature tracking devices, and while some return to the aviary, many have been seen in the wild.
In other ongoing studies, a group of international experts from various scientific institutions is conducting studies on genetic variations in song and diet of finches on Santa Cruz island. They want to see how the introduction of human food has changed the diet of the finches. Preliminary data suggests that there are important differences in behavior and diet at various sites. This project is run in partnership with the Ministry of Environment, Galapagos National Park, and the Charles Darwin Foundation, with financial support from the Earthwatch Institute.
Finally, research done by Peter Grant of Princeton University on Daphne Mayor island, showed that changes in Finch beak sizes can be observed in just two or three generations. That is a much shorter period of time than was expected. This is due to weather as the level of rainfall is important for finches that feed on seeds. After the dry season, finches that survived drought had slightly wider beaks.
If you enjoyed this post, learn more in our Galapagos Bird Species blog.
For more information about Galapagos Tours to see Darwin’s Finches first hand (as well as many other fascinating bird and mammal species), Contact a member of our team or call our toll-free numbers.
In conclusion, the Galapagos Darwin’s Finch is one of the true characters at the archipelago. Some tourists choose to pay them little heed, there are after all many other attractive creatures vying for your attention. But for those with an active imagination, and a natural sense of awe, the humble Galapagos Finch is a true wonder. Just remember the epic voyage of the grassquit arriving to these islands in the middle of the ocean. Imagine Darwin collecting and examining his specimens, and his famous eureka moment. Take a moment to marvel at these little miracles of nature. Every single one of us owes a debt to the little Galapagos Finch.
