Link to Life on earth: 8- Lords of the air documentary
Documentary Description
This program focuses on birds. The feather is key to everything that is crucial about a bird: it is both its aerofoil & its insulator. The earliest feathers were found on a fossilized Archaeopteryx skeleton in Bavaria. However, it had claws on its wings & there is only one species alive today that does so: the hoatzin, whose chicks possess them for about a week or so. Nevertheless, it serves to illustrate the probable movement of its ancestor. It may have taken to the trees to avoid predators, & over time, its bony, reptilian tail was replaced by feathers & its heavy jaw evolved into a keratin beak. Beaks come in a variety of shapes depending on a bird’s feeding habits: examples given include the pouched bill of a pelican, the hooked beak of the vulture and the elongated mouth of the hummingbird. Attenborough hails the tern as one of the most graceful flyers & the albatross as a skilled glider. The swift is shown as one of the fastest: it can fly at 170 kmh. Birds communicate through display & or song, & the elaborate courtship rituals of New Guinea’s birds of paradise are shown. All birds lay eggs, & the range of different nesting sites and parenting skills is explored. Finally, Attenborough visits Gibraltar to observe migratory birds. These rely on thermals when flying overland & use height to conserve energy when crossing oceans. It is estimated that some 5,000 million southbound birds cross the Mediterranean Sea each autumn.
