What You Will See

The Galapagos archipelago is home to some of the highest levels of endemism (species found nowhere else on earth) anywhere on the planet. About 80% of the land birds you will see, 97% of the reptiles and land mammals, and more than 30% of the plants are endemic. More than 20% of the marine species in Galapagos are found nowhere else on earth. Favorites include the giant Galapagos tortoise, marine iguana, flightless cormorant, and the Galapagos penguin—the only penguin species to be found in the Northern Hemisphere. Read more about the flora, fauna, and landscape you can expect to see on your trip.

Flora of Galapagos

Many visitors to Galapagos are surprised to be greeted by desert-like vegetation—most are expecting a continuation of the lush greenery they witnessed on mainland Ecuador. In fact, the majority of the archipelago’s land area is covered by the brown and grey vegetation often found in deserts. The Galapagos Islands are situated in the Pacific Dry Belt, and only the highest altitudes of the larger islands receive enough rainfall to support tropical plant life.

Geologically speaking, the islands are young, and much of the island’s plant life reflects this; many species seem to be in the midst of the evolutionary process, which makes classifying them a difficult task. To date, the islands are believed to be home to between 500 and 575 native species or subspecies of vascular plants and approximately 190 species introduced by humans. By comparison, mainland Ecuador has about 20,000 species—the discrepancy between species numbers on the Islands and the mainland highlights the fact that the Galapagos are a most harsh environment for plants to colonize. It is worthy of note that more than 30% of plant species found in Galapagos are endemic (are not found anywhere else on earth).

The flora of Galapagos can be grouped into three major zones of location: the coastal zone, mid-level dry areas, and upper-level humid areas.

• Coastal plants are found in the narrow zone near the shore and are distinctive because of their tolerance to salty conditions. Mangrove trees are one of the most common plants found in this zone, and they serve an important role as the breeding sites for many birds, such as pelicans and frigatebirds. They also provide much needed shade regions for iguanas and sea lions, as well as refuges for turtles.
• The dry area is the most extensive zone in Galapagos and is comprised of plant species that are highly adapted to drought-like conditions, such as succulent cacti and leafless shrubs that flower and grow leaves only in the brief rainy season.
• Located above the dry zones are the small-in-area, but very lush and green, humid zones. Scalesia trees form a very dense forest in the humid zone, with their branches adorned with mosses, liverworts, and epiphytes—non-parasitic plants which use larger trees only for support.

Fauna of Galapagos Back to top

Seabirds

The Galapagos Islands are a mecca for tropical seabirds, of which there are 19 breeding species – 5 of these are endemic. Seabirds are always evident as you cruise between the islands. They include boobies, cormorants, pelicans, frigatebirds, tropicbirds, albatrosses, shearwaters, gulls, and penguins.
Some of these species are found on many islands, others have tiny populations and are confined to certain parts of a single island. Each species has evolved its own behaviour patterns related to feeding and breeding, and in any month you will find some seabirds displaying, incubating eggs or feeding their young.

The endemic seabirds are: the Galapagos penguin (Fernandina and Isabela Islands, population highly variable depending on El Nino events); the Waved albatross ( Espanola Island, about 12,000 pairs); the Flightless cormorant (Fernandina and Isabela, 700 – 900 pairs); Swallow-tailed gull (widespread, 10,000 – 15,000 pairs); and the Lava gull (6 islands, only 300 – 400 pairs remaining).

Land birds

Of the 29 resident Galapagos landbirds, 22 are endemic and all of them are thought to have colonized the islands from the South American mainland. Although largely dull in color, they compensate by their extreme tameness. Beebe’s attempt to photograph the flycatcher was foiled because the bird clung to the camera, and Darwin remarked on the doves which alighted on his arms and head.

The Woodpecker finch (Cactospiza pallidus) is one of the few tool-using birds in the world. The Sharp-billed ground finch (Geospiza difficilis) parasitizes seabirds by hopping on the backs of masked and red-footed boobies where they peck at the skin until they are able to drink their blood.
The Galapagos Islands harbor several endemic avian predators, notably the Galapagos hawk (Buteo galapagoensis), the fierce Galapagos short-eared owl (Asio flammeus), and the barn owl (Tyto punctissima). The female hawk has the unusual habit of mating with several males, all of which help to incubate the eggs and rear the young. The partly diurnal short-eared owl, widespread in the Galapagos, tackles large seabird chicks by attacking the neck. The barn owl feeds mostly on rodents and insects.

Among the lesser known Galapagos landbirds are the tiny endemic rail (Lateralus spilonotus), which inhabits higher ground above 1500 feet, the non-endemic Paint-billed crake (Neocrex erythrops), and the endemic Galapagos martin (Progne modesta).

Land Iguanas

There are two species of land iguana found in the Galapagos Islands. Conolophus subcristatus is native to six islands, and Conolophus pallidus is found only on the island of Santa Fe. They are large (more than 3 feet long), yellowish animals, with males weighing up to 30 pounds. Galapagos iguanas are thought to have had a common ancestor which floated out to the islands from the South American mainland on rafts of vegetation.

Land iguanas live in the drier areas of the islands and in the mornings are found sprawled beneath the hot equatorial sun. However, to escape the heat of the midday sun, they seek the shade of cactus, rocks, trees or other vegetation. At night they sleep in burrows dug in the ground, to conserve their body heat. The land iguanas show a fascinating interaction with Darwin’s finches, raising themselves off the ground and allowing the little birds to remove ticks. They feed mainly on low-growing plants and shrubs, such as the cactus, as well as fallen fruits and cactus pads. These succulent plants provide them with the moisture they require during long, dry periods.
Land iguanas reach maturity between 8 and 15 years of age. Males are territorial and will aggressively defend specific areas, that typically include more than one female. Following the mating period, the female iguanas migrate to suitable areas to nest, and will lay between 2 and 25 eggs in a burrow dug in the sandy soil. The female defends the burrow for a short time, to prevent other females from nesting in the same place. The young iguanas hatch 3-4 months later, and take about a week to dig their way out of the nest. If they survive the first difficult years of life, when food is often scarce and predators are a danger, land iguanas can live for more than 50 years.

In 1976, wild dogs wiped out a colony of almost 500 land iguanas at Conway Bay on Santa Cruz. Together, the CDRS and GNPS launched an emergency rescue operation for the 60 or so survivors. Shortly thereafter, another large-scale attack occurred at Cartago Bay on Isabela, and 30 more iguanas were rescued. To help re-establish the land iguana populations, the GNPS and the CDRS began a breeding and rearing program for iguanas. They established a breeding center in Santa Cruz, to increase the populations that were seriously threatened by feral animals. Twelve years later repatriation started and it continues today. The CDRS and the GNPS carry out regular monitoring of this population.

The captive breeding program is reinforced by an ongoing campaign for the eradication and control of introduced species throughout the islands. The populations of wild dogs were eliminated from Cartago and Conway Bays, and goats were removed from several small islands, while pigs and wild cats are now controlled in critical areas on others.

Marine Iguanas

Just about every rocky shoreline in the Galapagos Islands is home to the marine iguana, the only sea-going lizard in the world. The marine iguana is an extraordinary animal which lives on land but grazes on a variety of seaweed, either on exposed rocks or by diving into the cold seawater. This habit, totally unique in iguanas, provides them with an abundant food source but can make them vulnerable to predation by sharks and other large fish. They are found nearly throughout the entire archipelago, in coastal concentrations of up to 4,500 individuals per mile. The total population has been estimated at between 200,000 and 300,000.

The marine iguana eats mainly algae, found underwater and in the tidal pools. They have also been known to consume crustaceans and grasshoppers. Its short, blunt nose is adapted for eating algae growing on rocks. Its flattened tail is perfect for swimming. They get rid of the excess salt taken in from the water by a special gland connected to the nostrils. The marine iguana is an excellent example of a species adapting to its environment.

When marine iguanas go hungry, they don’t just become thinner, they get shorter too. A scientist recently found that in times of El Nino-induced famine, the marine iguanas will shrink in length and then will regrow as food becomes plentiful again. This finding, reported in the scientific journal Nature, is the first of a shrinking adult vertebrae. The adult iguanas can switch between growth and shrinkage repeatedly throughout their lifetime. The researchers postulate that bone absorption accounts for much of the reduction. The iguanas literally digest part of their bones.

In the breeding season, males defend territories on land where they mate with the females, who then lay their eggs in burrows. The iguanas show their color as they mature – the young are black, while adults range from red and black to black, green, red and grey depending on the island.

Recent research has found high mortality of Galapagos marine iguanas on Isla Santa Fe as a result of subtle long-term effects of the 2001 oil spill from the grounded tanker Jessica.

Landscapes and Geology of Galapagos Back to top

Galapagos is located on the Nazca tectonic plate. This perpetually moving plate is heading eastward over the Galapagos hot spot and has formed the chain of islands. The islands were formed through the layering and lifting of repeated volcanic action. This geographic movement is correlated to the age of the islands, as the eastern islands are millions of years older than the western islands.

Most of the islands have a distinctive conical shape that is often associated with volcanic action. The mountainous islands have been formed through continuing eruption, building layer upon layer. Due to this volcanic formation, the islands are characterized by many steep slopes, with heights ranging from a few meters above sea level to more than 5000 feet above sea level.

Each major island, with the exception of the largest island, Isabela, consists of a single large volcano. Isabela was formed when six volcanoes joined above sea level. Geologically, the Galapagos Islands are quite young, probably no more than five million years old. Some of the westernmost islands, which are the most volcanically active, may only be hundreds of thousands of years old and are still being formed today.

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