E08 - David Attenborough - 1979 - 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.
