Sunday, 24 June 2001
This is just a sampling of the stuff we learned and did while in the Galapagos. They are in no particular order, and no particular relevence.
Seven different islands have their own species of lava lizards.
The marine iquanas are endemic (found nowhere else) and there are seven subspecies. They are the only ones in the world. They feed on Ulva (a type of algae) and to get it, they dive up to 60 feet and can spend up to an hour at a time under water. They sit in the sun and let the heat help them digest the algae as it sits in their stomachs. They spray the excess salt through their nostrils. Darwin once threw a marine iquana into the ocean over and over again and he also tied a brick to one to see how long it could hold its breath.
Giant tortoises are found in the Indian Ocean on Aldabra Island in the Seychelles and on the Galapagos Islands. Males cam weigh up to 250 kilograms, and nobody knows exactly how long they can live. It is probable that some of the tortoises around today were there when Darwin visited (170+ years). Whalers used to catch the tortoises and stack them in their holds for food, because these guys can go for months without fresh food or water. Whenever the sailors needed fresh meat, they would just bring one up to the deck and turn it upside down. Man, and critters that he has introduced, are directly responsible for the decimation of the Giant Tortoise.
The Galapagos penguin is the northernmost penguin in the world. It swims with its front fins, and uses its feet to steer.
The flightless cormorant (endemic) is flightless due to a lack of predators, but it still holds its atrophied wings out to dry just like its flight-enabled kin. It is one of the rarest birds in the world (800 pairs).
Waved Albatross is endemic to the island of Espanola - the only place in the world where it reproduces. It has a wingspan of 8 feet. Albatross mate for life. They are great fliers, but horrible landers - they have a double-digit mortality rate when they land on land.
Frigate birds are related to pelicans, but instead of using their pouch to feed, it uses it to attract a mate. They have lost the ability to waterproof their feathers, so they can't land in water. They are cleptoparasitic, meaning they make their living by stealing food from other birds - usually in mid-flight.
There are three types of boobies found in the GI. They all plunge-dive at incredible speeds and then move underwater to catch fish. Red-footed boobies lay 1 egg, nest in trees and fish offshore. Blue-footed boobies fish in-shore, lays two eggs and nest on the ground. The second egg hatches several days after the first, so that it is at a disadvantage, if food is scarce, the bigger chick will push the smaller one out of the nest. You can tell the sexes apart by the size of their pupils - the male has the smaller ones). The Nazca Booby (formally the masked booby but now recognized as a distinct species) are the biggest. They nest on the ground on clifftops, and fish between the ranges of the other two boobies. Two eggs are laid but because food sources are not abundant, one chick always kills the other.
The Galapagos Hawk is endemic, and is the top of the food chain in the islands. Darwin once knocked one off of its perch with a rifle butt. They have no fear of man.
There are 14 Darwin's Finches, and these little guys helped him form the theory of evolution by natural selection. Each of them has a very special niche in the ecosytem, based on the food they eat and the shape of their beaks. There is a vampire finch (sharpbill ground finch) that draws blood from the base of the feathers of nazca and red-footed boobies when water is in short supply. There is also a carpenter finch which uses sticks to dig out its food.
Mother and pup sea lions recognize each other by cry and smell. Orphaned pups will not be adopted by other sea lions. Sea lions have been known to play water polo using a marine iquana in place of the ball.
Differences between sea lions (found in the GI) and seals, which are not: seals do not have external ears, sea lions do; seals cannot support themselves on their front flippers and creep along the ground; seals swim with their posterior flippers, sea lions with the front flippers.
The GI are home to the largest species of shark - the whale shark. It reaches 15 m in length, and may reach 18 m or more. Its weight can exceed 10 tons. It feeds mostly on plankton and is not dangerous to humans.
The age of the islands ranges from 2.3 million years to 700,000 years. The most recent eruption in the islands was 1998, and on average they have a major eruption every 2-3 years.
Darwin only visited 4 of the islands during his voyage on the Beagle in 1825 - and he didn't visit the one named after him.