Natural history of Trinidad and Tobago hummingbirds to the primitive cave-dwelling oilbird (that uses sonar to fly in the dark) to the spectacularly beautiful scarlet ibis. The islands are within a few miles of Venezuela, and the species are therefore typical of tropical South America. However, the variety (although quite exceptional for such a small geographic area) is somewhat impoverished compared to the mainland, as would be expected with small islands. The resident breeding birds are augmented in the northern winter by migrants from North America. Tobago has only about half the number of bird species of Trinidad, but about 22 birds have been reported only
Endemic flora of Trinidad and Tobago rate of endemism, probably as a result of its geological history. The islands of Trinidad and Tobago lie on the South American continental shelf, and were both connected to the mainland during the Pleistocene. Tobago was separated from the mainland about 13,000 years ago; Trinidad was connected until more recently, and may only have become separated about 1,500 years ago. The flora of Trinidad and Tobago has been estimated to include about 2,500 vascular plant species. Although historically as many as 222 species were thought to be endemic, a study by Veerle Van den Eynden and colleagues at the University