Cocos Island in the context of "Dolphins"

Costa Rica, officially the Republic of Costa Rica, is a country in Central America. It borders Nicaragua to the north, the Caribbean Sea to the northeast, Panama to the southeast, and the Pacific Ocean to the southwest, sharing a maritime border with Ecuador to the south of Cocos Island. It has a population of around five million in a land area of nearly 51,180 km (19,760 sq mi); the capital and largest city is San José, home to around 350,000 residents and two million people in the surrounding metropolitan area.

Humans have been present in Costa Rica since between 7,000 and 10,000 BC. Various indigenous peoples lived in the territory before it was colonized by Spain in the 16th century. Costa Rica was a peripheral colony of the Spanish Empire until independence in 1821 as part of the First Mexican Empire, followed by membership in the Federal Republic of Central America in 1823, from which it formally declared independence in 1847. The country underwent gradual modernization under relatively stable authoritarian rule until the late 19th century, when it promulgated a liberal constitution and held the first free and fair national election in Central America.

The Cocos plate is a young oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America, named for Cocos Island, which rides upon it. The Cocos plate was created approximately 23 million years ago when the Farallon plate broke into two pieces, which also created the Nazca plate. The Cocos plate also broke into two pieces, creating the small Rivera plate. The Cocos plate is bounded to the northeast by the North American plate and the Caribbean plate. To the west it is bounded by the Pacific plate and to the south by the Nazca plate.

The only land above water on the Cocos plate is Cocos Island, which is administered by Costa Rica and lies approximately 550 km (342 mi; 297 nmi) southwest of the Costa Rican mainland.

Darwin's finches (also known as the Galápagos finches) are a group of about 18 species of passerine birds. They are well known for being a classic example of adaptive radiation and for their remarkable diversity in beak form and function. They are often classified as the subfamily Geospizinae or tribe Geospizini. They belong to the tanager family and are not closely related to the true finches. The closest known relative of the Galápagos finches is the South American dull-coloured grassquit (Asemospiza obscura). They were first collected when the second voyage of the Beagle visited the Galápagos Islands, with Charles Darwin on board as a gentleman naturalist. Apart from the Cocos finch, which is from Cocos Island, the others are found only on the Galápagos Islands.

The term "Darwin's finches" was first applied by Percy Lowe in 1936, and popularised in 1947 by David Lack in his book Darwin's Finches. Lack based his analysis on the large collection of museum specimens collected by the 1905–06 Galápagos expedition of the California Academy of Sciences, to whom Lack dedicated his 1947 book. The birds vary in size from 10 to 20 cm (4 to 8 in) and weigh between 8 and 38 grams (0.3 and 1.3 oz). The smallest are the warbler-finches and the largest is the vegetarian finch. The most important differences between species are in the size and shape of their beaks, which are highly adapted to different food sources. Food availability was different among the islands of the Galapagos and could also change dramatically due to natural events such as droughts. The birds are all dull-coloured. They are thought to have evolved from a single finch species that came to the islands more than a million years ago.