Encyclopedia of Islands

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Lesser Antilles

The Lesser Antilles begins east of the Virgin Islands (which here are considered part of the Puerto Rican Bank). The 25 larger and hundreds of smaller-to-tiny islands lie along the leading edge of the Caribbean plate, which is colliding with the North American plate (subduction).

Many of the islands are of volcanic origin, and most of the remaining small cays and islets are of coral origin. Overall, this region of small volcanic and coral islands contains only 6% of the overall landmass of the Antilles.

The islands in the northwest are collectively called the Leeward Islands. Within this subregion is the St. Martin Bank, which includes the islands of St. Martin, Anguilla, and St. Barthelemy. At times of low sea levels, they would have formed a single island approximately 5949 km2.

South of this, but still within the Leeward Islands, is the St. Kitts Bank, including the islands of St. Eustatius, St. Christopher (i.e., St. Kitts), and Nevis. At low sea levels, this bank would have been a single island of approximately 1546 km2. The islands of Barbuda and Antigua are located on a bank east of the above, which at times of low sea levels would have been over 4274 km2 in area.

The Leeward Islands are relatively low-lying and similar to the Virgin Islands. South of these are the much more mountainous islands of Montserrat, Guadeloupe, and Dominica, still considered part of the Leeward Islands by most biogeographers.

South of the Martinique Passage (located between the islands of Dominica and Martinique), a series of islands are isolated from one another by deep-water passages.

Lesser Antilles

These islands are collectively known as the Windward Islands and range from Martinique in the north to Grenada in the south. There is biological evidence for excluding Trinidad, Tobago, Margarita, and the Netherlands Antilles from the true Antilles.

The Poinars examined over 3000 pieces of amber, and the most frequently occurring organisms were worker ants (497), winged adult ants (286), gall midges (197), bark lice (173), and stingless bees (156). They also documented the remains of small vertebrates such anoles and geckos, soft ticks and hairs from rodents, the feather of an Antillean piculet (a small primitive woodpecker-like bird), and a few vertebrae and ribs of a tiny island shrew (Nesophontes).

What is remarkable is how many Antillean plants and animals documented in Dominican amber, including the algarrobo tree itself, are now extinct or extirpated from the Antilles. For example, of the seven genera and subgenera of bees documented by the Poinars in amber, all are now extinct in the Antilles (whereas relatives survive in tropical Central and South America). The reasons and timing of these extinction events in the Antilles may relate to climate change, because ice ages during the Pleistocene in North America led to drying and cooling in the Antilles, and lowering sea levels changed the size and shape of Antillean islands.