Tag Archives: Darwin

Charles Darwin’s Galapagos Finches

 Galapagos, Ecuador - Mangrove finch

Galapagos, Ecuador – Mangrove finch

Finches were one of the many birds Darwin studied in the Galápagos Islands before publishing his monumental work on natural selection. Today, the mangrove finch is on the verge of extinction in the Galápagos. There are around 100 left, with just 20 breeding pairs. To keep the finches from disappearing altogether, the Charles Darwin Research Station and San Diego Zoo have engaged in a captive breeding program.

Recently, a third group of fledging mangrove finches were released on Isabela island. All birds are fitted with miniature tracking devices. Some returned to the aviary, but several finches released in past years have been seen in the wild. This showed finches raised in captivity are able to survive long-term.

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Monkeys of Ecuador’s Pacific coastal region

Monkeys of Ecuador's Pacific coast

Monkeys of Ecuador’s Pacific coastal region

Monkeys are similarly abundant on either side of Ecuador’s central Andes mountain range. Following on from last week’s blog on inhabitants of the Amazon jungle, we’ll now look at four species of the Pacific coastal regions. The following text is adapted from the Ministry of Tourism’s official observation guide, Primates of Ecuador.

Brown-headed Spider monkeys [Ateles fusciceps] – Also known as bracilargo (long arms) or chuba (Afro-Ecuadorian), these measure from 31-63cm (without tail). It lives in primary or old secondary forests, where it prefers tall, thick trees with wide treetops and overlapping branches. These features provide it with good visibility of the forest and rapid traveling. You might also find it on the ground eating clays in salt licks, which are natural mineral deposits that exist in nutrient-poor ecosystems. It can travel up to 3 kilometers (1.86 miles) per day; its body is well designed for this. It has a complex social organization that consists in groups that stick together or separate depending on food availability. Larger groups travel in times of abundant fruit.

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The Great Frigatebird of the Galapagos Islands

great-frigatebirds-Galapagos-Islands

Great Frigatebird

The Great Frigatebirds are some of the most iconic inhabitants of the Galapagos Islands, especially when dramatically inflating their red gular sacs to attract mates. When not breeding or caring for young, however, they can be well out of sight — soaring up to 2.5 miles high in the air!

This would be impressive for any seabird, but the truly amazing fact is that frigatebirds have been tracked by GPS flying continuously (without any rest) for 56 days! Averaging 260 miles per day with 400 miles possible in perfect conditions, that would be a global round-trip in 95 days.

Most seabirds (albatrosses, petrels, sulids, etc.) glide for maximum efficiency. A frigatebird’s heartrate when soaring at altitude, flapping once every 6 minutes, is similar to when resting in a nest. Updraft currents allow them to ride upwards before swooping, in rollercoaster fashion.

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Charles Darwin in the Galapagos Islands

Beagle-voyageThe most famous visitor to the Galapagos Islands was also the co-author of humankind’s most influential scientific theory. Charles Robert Darwin sailed around the Islands in 1835 as part of a longer voyage around the globe on a Royal Navy vessel named HMS Beagle.

In five weeks, Darwin the young naturalist and his more experienced crewmates landed on just four islands to explore the geology and wildlife. Today known almost universally as Isabela, Santiago, San Cristobal and Floreana, in Darwin’s notes the islands were Albemarle, James, Chatham and Charles islands (the latter after King Charles II, not Darwin).

The abundant and diverse flora/fauna on the Islands (most notably the variety of finches) were the principal source of Darwin’s theory of evolution by natural selection. However, it wasn’t until 1858, after Alfred Russel Wallace had written to Darwin about the same idea, that both men jointly published their papers to the scientific community.

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