International Polar Year 2007-2008 (British Antarctic Territory (BAT) 2007)

Souvenir Sheet International Polar Year 2007-2008 it reflects the thematic directions:

Birds (Aves), a subgroup of Reptiles, are the last living examples of Dinosaurs. They are a group of endothermic vertebrates, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the 5 cm (2 in) bee hummingbird to the 2.75 m (9 ft) ostrich. They rank as the class of tetrapods with the most living species, at approximately ten thousand, with more than half of these being passerines, sometimes known as perching birds. Birds are the closest living relatives of crocodilians.