Why do birds have feathers?

the long version

An original new science series which explores the key characteristics that divide the main animal and plant groups, and looks at how these characteristics have evolved over time. The information is supported by examples that highlight the quirky and amazing qualities of the natural world, as well as revealing the dazzling variety within each group. Why do Birds have Feathers? looks at the features that make birds so unique. It describes how birds evolved from small dinosaurs, and looks at how feathers and flight developed. Bird senses, behaviour, habitats and flightless birds all also feature.