Invasive species are often bad news. This is especially true in a place like the Galapagos Islands, where a single introduced species can wreak havoc on sensitive ecosystems and have a devastating imp...
The Galapagos archipelago is surrounded by thousands of miles of open ocean, which provide seabirds with a prominent place in the fauna of the islands. There are nineteen resident species (five are endemic), most of which are seen by visitors. There may be as many as 750,000 seabirds in Galapagos, including thirty percent of the world’s blue-footed boobies, the world’s largest red-footed booby colony, and perhaps the largest concentration of Nazca boobies in the world.
Few species of land birds inhabit the Galapagos, and twenty-two of the twenty-nine resident species are endemic to the islands. Their presence in Galapagos, however, is difficult to explain. They may have arrived by strong winds, although luck must have played a big part.
Those travelers who are not birders or who feel that birds are “nice, but uninteresting,” are in for a most pleasant surprise. For the most part, land birds are not exciting by appearance, as they generally are rather dull-colored. However, their “tameness” is unsurpassed, which makes them a pleasure to watch. In addition, the members of the nesting seabird communities of the Galapagos Islands are most unusual, both visually and behaviorally interesting, as well as extremely entertaining.
MEET THE BIRDS OF THE GALAPAGOS
Most penguins are associated with the colder regions of the Southern Hemisphere, but the cool Humboldt Current flowing from Antarctica along the South American coast enables the Galapagos penguin, the most northerly penguin in the world, to live here. Although they normally breed on the western part of Isabela and Fernandina, a small colony is often seen by visitors at Bartolomé. They are also occasionally present on Floreana and James as well. Breeding can occur year-round; two broods a year are possible under good conditions. Colonies are small and not tightly packed with nests.
This flightless bird is one of five endemic seabirds in the islands. A penguin’s clumsiness on land belies its skill and speed underwater. The best way to appreciate their agility is to snorkel with them; it is a lot of fun, but do not even try to keep up, as a penguin underwater is amazingly quick!
One of the world’s most graceful flying birds is the magnificent waved albatross, which amazingly, can spend years at sea without touching land. It is the largest bird in the islands, averaging 3 feet in length, up to an 8 feet wingspan, and reaching up to 11 pounds in weight. Apart from a few pairs which have bred on Isla de la Plata, off the Ecuadorian coast, the entire world population of some 12,000 pairs nests on Hood. Egg laying occurs from mid-April to late June, and the colonies are active, with parents feeding their single young through December. When the fledged bird finally leaves the nest, it does not return for 4 or 5 years. From January to March, all the birds remain at sea.
The waved albatross engages in one of the most spectacular ritualized courtship displays of any bird. Courtship tends to occur in the second half of the breeding season; October is the busiest month, but you may see it anytime that the colony is occupied. The display involves a perfectly choreographed “dance” of up to 20 minutes of bowing, bill clicking, bill circling, swaying and freezing, and honking and whistling. Watch it here:
The unmistakable red-billed tropicbird is one of the most impressive of the Galapagos seabirds. The most noticeable feature of this splendid white bird is its pair of long tail streamers—two elongated feathers often as long as the rest of the body. The birds are 2.5 long (including the tail feathers) and have a wingspan of just under 3.5 feet.
They are extremely graceful in the air and often fly by in small groups, uttering a distinctive, piercing shriek. The coral-red bill and black eye stripe are noticeable at closer range. These birds nest in crevices and holes in cliffs or rock piles on most of the islands, but are most frequently seen from trails that follow cliff tops, such as on South Plaza, Genovesa and Hood. They feed far out to sea, plunge diving for fish and squid.
The brown pelican is instantly recognizable; with its huge pouched bill and large size (4 feet long with a 6.5-foot wingspan), it is often the first bird that visitors identify. As its name suggests, these pelicans are generally brownish in color. During the breeding season, however, the adults have bright white and chestnut markings on their heads and necks. They nest year-round in most of the islands.
These pelicans have wide fingered wings and are good gliders. They are often seen flying in a squadron-like formation, flapping and soaring in unison to create an elegant aerial ballet. They feed by shallow plunge diving and by scooping up as much as 2.5 gallons of water their pouches. The water rapidly drains out through the bill and the trapped fish are swallowed. It seems like a straightforward procedure, but apparently it is a difficult skill for the birds to acquire. Although parents raise frequent broods of two or three chicks, many of the fledged young are unable to learn the scoop-fishing technique quickly enough, and thus, starve to death.
The blue-footed booby is perhaps the most famous of the Galapagos birds and is often the first type of booby seen by visitors. Large, colonies on Seymour and Hood are present throughout the year. This large, whitish-brown seabird grows from 2.5 to 3 feet in length and has a wingspan of about 5 feet. The blue-footed booby really does have bright blue feet, which it picks up in a slow, most dignified fashion when performing a courtship display. Bowing, wing spreading and sky pointing, with its neck, head and bill stretched straight upward, are also features of courtship. Watching this clownish behavior is one of the highlights of any Galapagos trip!
At first glance, the males and females are almost identical, but they can be told apart; the larger females have a slightly bigger pupil and they honk, whereas the males whistle. Courtship, mating and nesting occur year-round, although nesting is a euphemism for a scrape on the ground (literally) surrounded by a ring of guano. The young, of which there may be one, two or three, are covered with fluffy white down which can make them look larger than their parents. In a good year, all three of the young may survive; otherwise, the strongest one or two will out compete the weakest, which subsequently dies of starvation.
Recently given full species status, the Nazca booby, which has split from the masked booby, is pure white in color with a black band at the edge of its wings and tail. A blackish area of bare skin surrounding its reddish-pink or orange bill forms the facemask, which gave the bird its previous name.
The Nazca booby is the largest of the Galapagos boobies—with a length of 3 feet and a 5 to 6 foot wingspan—and it is found on most of the islands. Males and females look similar, but like the blue-footed booby, their calls differ; the smaller males whistle while the females utter a trumpeting quack. Because they are large birds, they often nest near cliff tops to give themselves an advantage when taking off.
Breeding, unlike other boobies, takes place on an annual cycle that varies from island to island.
On Genovesa, the birds arrive in May; courtship, mating and nest building ensue, and eggs are laid from August to November. Most of the young have fledged by February and the colony goes out at sea until May. On Hood, however, the colony is present from September to May, with egg-laying occurring from November to February. Despite the location, the Nazca booby always lays two eggs while nesting, but even in a good year with plenty of food, the older sibling ejects the younger from the nest and only one survives.
The red-footed booby is the smallest of the Galapagos boobies, with a length of 2.5 feet and a 4.5-foot wingspan, and is readily distinguished by its red feet and blue bill with red base. Most adults are brown; however, about five percent are white, which is solely a different color phase and does not represent a new or hybrid species. The red-footed booby is the most numerous of the Galapagos boobies, but is also the least frequently seen. This is because it is found only on the more outlying islands, such as Genovesa, where a sizable colony estimated at 140,000 pairs exists. It feeds far out to sea, avoiding competition with the blue-footed booby, which feeds close inshore, and the Nazca booby, which feeds intermediately.
The nesting behavior of this booby is quite different from the others. It builds rudimentary nests in trees, as opposed to the guano-ringed scrapes on the ground of the other boobies, and lays only one egg. This usually happens when food is plentiful and can occur at any time of the year.
Black frigatebirds, with their long scimitar wings and forked tails, hang like sinister kites in the wind. They are able hold a single position in the sky, as if suspended from invisible strings, and from their airborne perch they harry gulls and terns until the latter release their catch. This occurs because frigatebirds have a very small preening gland and are not able to secrete enough oils to waterproof their feathers; therefore, they cannot, unlike other birds, dive underwater to catch prey. They are, however, able to catch fish on the surface by snatching them up with their hooked beaks.
Despite the menacing look imparted by its long, hooked beak, the frigatebird is actually quite beautiful. This large, elegant, streamlined, black seabird has an almost 8-foot wingspan. These birds are outstanding fliers and have the largest wingspan to weight ratio of any bird on the planet.
There are two different species of frigatebirds found in the Galapagos. Although there are colonies on many of the other islands, North Seymour Island has a constantly active, magnificent frigatebird colony and affords the best bird-viewing opportunities. Great frigatebirds tend to go further out to sea and are found more often on the outer islands. Telling the all-black, male species apart is problematic. The magnificent frigatebird, at 3.6 feet in length, is about 2 inches longer than the great frigatebird—a difference that is almost impossible to observe in the field. Also, the male magnificent has a metallic-purplish sheen to its black plumage, whereas the great frigate has a greenish hue. Again, it takes an experienced eye to tell the difference.
Females are easier to distinguish. Magnificent females have white underparts with a black throat and a thin, blue eye-ring. Great females have white underparts, including the throat, and have a reddish eye-ring. Once the females are identified, you can assume that their mates are of the same species. Immature birds of both species, in addition to having white underparts, also have white heads.
As with many Galapagos seabirds, a frigatebird’s courtship display is quite spectacular. It is the females who do the conspicuous searching out and selecting of mates. The hens take to the air above the rookery to look over the males, who cluster in groups. Whenever a female circles low overhead, the males react with a blatant display of wooing. The males have scarlet gular pouches (appropriately shaped like hearts) hanging under their necks, which are inflated to football-sized balloons. It takes about 20 minutes to fully inflate the pouch, and the male normally sits on a tree and displays it skyward in order to attract passing females. In addition, the male vibrates its wings rapidly back and forth and entices the females with loud clicking and drumming sounds.
Once the pair is established, a honeymoon of nest building begins. In the structured world of the frigatebird, it is the male’s job to find twigs for the nest. The practical frigates will not hesitate to steal twigs from their neighbors’ nests, so the females must stay home in order to guard their nests against thieves.
Great Blue Heron
The great blue is the largest heron in the Galapagos, with its 4.5-foot length and almost 6.5-foot wingspan. Despite its name, the blue heron is a mostly gray bird, but is easily recognized by its long legs and great size. Like many members of this family, it often stands with its head hunched into its shoulders; it maintains this position when flying as well, with its long legs trailing behind.
Great blue herons are found along the rocky coasts of most of the islands in the Galapagos, often standing motionless as they wait for fish to swim by. They have also been known to eat lizards, as well as young marine iguanas and birds for food. Blue herons tend to live alone or in pairs, but occasionally form a small colony of up to six nests. They breed year-round and often nest in mangroves.
Yellow-Crowned Night Heron
This common heron tends to feed at night, but can often be seen during the day in shaded areas along the coasts of each island in the Galapagos. It is a stocky, gray heron with a black and white head and yellow crown. Because of its nocturnal habits, its eyes are larger than other herons. They breed in single pairs and build nests year-round in mangroves or under rocks.
This common egret is also known as the great or the American egret. This all-white heron is large, measuring 3.5 feet in length, with a 4.6-foot wingspan. It can also be identified by its yellow bill and black legs and feet. Despite its name, it is less commonly seen than the great blue heron, but found in similar habitats and occasionally inland.
This relatively small, white heron—1.7 feet long with a 3-foot wingspan—is distinguished from the common egret at a distance by its shorter neck and stockier appearance. Within closer range, its yellow legs and feet are more noticeable. This bird originated in Africa and southern Eurasia, and was unknown in the Americas until the 1800s. It was first recorded in the Galapagos in 1965, and is now common in pasturelands, especially in the highlands of Santa Cruz where the birds are most often seen.
This endemic hawk is the only raptor that breeds in the islands. These birds are dark brown, with yellow legs, feet and ceres (the fleshy area at the base of the bill), and have much broader wings than similarly sized seabirds. Immature birds are lighter in color and are heavily mottled.
These predatory birds have no natural enemies and are relatively fearless. This has led to their extinction by hunters on several islands, including Santa Maria, San Cristóbal, Seymour, Baltra, Genovesa and Daphne. They have been severely reduced on Santa Cruz as well, and only about 150 pairs are estimated to remain in the Galapagos. James, Bartolomé, Hood, Santa Fe, Fernandina and Isabela are the best islands on which to see them.
Breeding occurs year-round, but is most frequent from May to July. The birds practice cooperative polyandry, where a single female has two or more mates, and all the adults help in raising the young. It is not easy to separate the sexes, but the female is generally larger than the male.
Lava & Striated Heron
The lava heron, small and dark with its yellow-orange legs and 2-foot wingspan, is the only endemic heron in the Galapagos. Its dark green plumage camouflages it well against the lava shorelines where it stealthily hunts for prey, although immature birds are brown and streaked. The species breeds year-round, but September through March is its preferred breeding period. Their nests are usually solitary (occasionally in twos and threes) and are found under lava outcrops or in mangrove trees. They are common on the rocky shores of all the islands, but because of their camouflage and solitary nature, are a bit difficult to spot. Our naturalist guide should be able to point one out to you with little problem.
The striated heron is about the same size, but paler in color than the lava heron. Ornithologists are uncertain if the lava heron is simply a variety of the striated heron, whether the two can hybridize, or whether they are distinct species.
The lava gull is the rarest gull species in the world; only about 400 pairs are estimated to exist. Despite this fact, there is a very good chance of viewing one, as they are widely distributed in the Galapagos. The lava gull is about 1.8 feet long and is generally dark gray to black in color, with white eyelids. They are solitary nesters and breed throughout the year.
Brown Noddy Tern
The brown noddy tern, as its name suggests, is generally dark brown in color with a whitish forehead, and is frequently seen feeding with pelicans. This tern often tries to catch fish scraps from the water that drains out of a pelican’s bill, and has even been seen perching on the pelican’s head to better position itself. This bird is 1.27 feet long, has a 2.5-foot wingspan, and nests in small colonies on cliffs and in caves thought the year.
This pretty little 8-inch long dove is endemic to the islands. Its underneath has a reddish hue, its upper parts are brownish, and it has green neck patches, blue eye rings and red legs and feet—a very colorful bird.
Breeding occurs year-round. Two eggs are laid in a haphazard nest of grass and twigs, usually either under a rock or in an abandoned nest of another species. When incubating, adults may walk away from a nest, feigning injury in order to lure predators away. This behavior evolved long before doves arrived in the Galapagos, and has been retained, even though it is of little advantage in the islands.
Probably the most famous of the Galapagos land birds are Darwin’s finches, so named because of their importance to Charles Darwin’s evolutionary theories. Darwin was fascinated, not only with the diversity of the thirteen species, but by how quickly they evolved from a common ancestor to adapt to the type of food supply on each island. These adaptations were mainly manifested in the shape and size of their beaks.
Darwin’s thirteen finches are the most famous and biologically important birds of the Galapagos, but some visitors may find them disappointing, as they are not very spectacular looking. These finches are endemic to the islands and are usually easily seen by visitors, although it takes an expert’s trained eye to tell the different species apart. All thirteen species are thought to have descended from a common ancestor, and their present differences in distribution, body size, plumage, beak size and shape, and feeding habits helped Darwin to formulate his evolutionary theories.
Hood provides the best opportunity for viewers to more easily separate three of the finch species. Here, you will find only the warbler finch, the small ground finch and the large cactus finch, with its massive bill. The others species found in the islands are more difficult to distinguish. There are tree finches, which are seen on the ground, ground finches that are seen in the trees, and cactus finches, which may be seen in all sorts of places in addition to cacti.
If you are interested in seeing all thirteen species, you will need to do some traveling. The medium tree finch is found only in the highlands of Santa Maria. The mangrove finch solely exists on Isabela and Fernandina. And of the islands with visitor sites, the large cactus finch is found only on Genovesa and Hood. The other finches are more widely distributed.