The Galapagos Islands, off the Ecuadorian coast in the Pacific, are the habitat for a unique fauna. Many indigenous (endemic) species developed far from the mainland, especially among the reptiles and birds. The most famous representatives are the kite-like land iguanas and marine iguanas as well as the giant turtles and Galapagos penguins.
Reptiles (reptiles) in the Galapagos
The representatives of this group of animals are the most conspicuous in the Galapagos, especially the lizards and turtles.
Up more than 1 m long, dark-colored, dragon similar looking marine iguana (Figures 5 and 6) inhabited in large numbers the Lavaküsten on some islands. They lie tightly packed, almost immobile, and sunbathe. With its prickly neck and jagged back crest, the marine iguana looks like a little dragon from the world of legends. It is therefore not surprising that earlier seafarers called these lizards “terrible sea dragons” and even CHARLES DARWIN called them “goblins of darkness” on his world tour (1835).
The marine iguana is the only species of lizard in the world that feeds on seaweed and other marine plants. To do this, they dive over 10 m deep and can stay there for up to an hour. The marine iguanas are specially adapted to this way of life: they have
- strong claws on their feet to hold onto the rocks in strong surf,
- sharp, flat teeth for rasping the plants under water,
- a long, strong, laterally compressed tail for rowing forward,
- Glands on the head that are connected to the nasal cavity and through which they excrete the excess salt ingested with seawater and food
- as cold-blooded animals a particularly careful heat regulation of their body. After every dip in cold water you have to warm up again on the hot lava rock (optimal body temperature approx. 35–37 °C).
Relatives of the marine iguanas live on some Galapagos Islands, the up to 1 m long, yellowish-orange to reddish-brown colored land iguanas (Fig. 7). They also have a prickly neck and back crest (dragon-like) and often sit motionless and almost motionless under the plants of the dry zone, e.g. B. tree cacti (opuntia), succulent ground plants (sesuvia, purslane). They feed on buds, flowers, fruits and leaves.
Male land iguanas are aggressive towards their rivals and defend their territory.
The most famous animals of the Galapagos Islands are the Galapagos giant tortoises, which gave the islands their name (Spanish: galapagos = German tortoise). The males can weigh up to 350 kg and reach an age of up to 200 years.
In adaptation to the different vegetation and different climatic conditions, two main species of Galapagos giant tortoises developed. For the residents of the dry zone of the islands with high temperatures, saddle armor (picture 8) and longer legs are characteristic. You can still reach twigs and leaves close to the ground.
The turtles of the cooler and more vegetation-rich highlands have a domed armor (Fig. 9), which leaves them little room to move. They mainly eat grass growing on the ground.
Birds in the Galapagos
There is a fascinating world of birds in the Galapagos Islands. These include both land and waders, e.g. B. the Galapagos buzzard, the sparrow-like Darwin finches (13 species), the Galapagos pigeons, as well as sea birds such as gannet species, albatrosses, frigate birds, gulls, cormorants, penguins, heron species.
The flightless cormorant (Fig. 10) is the only species of cormorant that has “forgotten” how to fly. He inhabits the lava coasts of some islands. Due to the regression of the forelimbs to “stubby wings”, it is adapted to a formerly enemy-free and nutrient-rich land habitat. His physique (short stubby wings, streamlined body, small sternum crest, strong feet) make him a good swimmer and skilful diver, so his source of food is the seashore.
The small Galapagos penguin (35–45 cm, Fig. 11) is the smallest and the furthest penguin species that penetrates north from the South Pole. It lives on the lava coasts of some islands (Fernandina, Isabela), lays 1–2 eggs in lava caves or crevices that the penguin pairs hatch together. Adapted by their physique, the Galapagos penguins are excellent swimmers (over 40 km / h) and divers, on the other hand they appear awkward on the rocks due to their waddling gait.
The largest bird of the Galapagos Islands (on Española) is the Galapagos albatross (wingspan approx. 2.4 m, goose-sized; pictures 12 and 13). He is an excellent flyer but has difficulty taking off and landing because of his weight.
The courtship behavior of these birds is unique to see. There is loud beaking, dancing, and petting each other’s necks with their beak.
The most common type of booby on the Galapagos is the blue-footed booby (Figs. 14 and 15). He is a good flyer and prey for his food (fish) in a dive from over 20 m height. During the breeding season, blue-footed boobies show interesting courtship behavior. It includes various characteristic postures, dancing waddling steps, mutual showing of blue feet, plus bright whistling from the male and hoarse screaming from the female.
The frigate birds (Fig. 16) are a symbol of the Galapagos Islands. They have a wingspan of up to 2 m and weigh up to 1.5 kg. They are excellent “sailors”. Frigate birds are “air pirates”. They steal from other birds in flight, e.g. B. gannets, the prey fish from the beak.
In addition to the animal species presented, there are a large number of other animal species that inhabit the Galapagos Islands and illustrate the diversity of the fauna.
In addition to vertebrates (e.g. mammals, reptiles, fish, birds), this also includes numerous invertebrates such as crabs.
The red cliff crab (Fig. 17) lives in the lava rock area directly at the water line. It feeds mainly on algae.
