55. Amethyst Sunbird This black bird used to be called the Black Sunbird. But in fact the black is set off by patches of iridescence that are only to be seen from some angles: a blue-green cap and an amethyst-purple throat. Feathers are unique in the animal kingdom, developed by evolution, it seems, from reptilian scales; and they’re wonderful for displaying colour. Every bird has a variety of different kinds of feathers: soft downy ones for insulating against heat and cold, more robust ones for a smooth surface to the wings, some just for decoration. It is vital to all birds that feathers are looked-after, and they devote a lot of time to preening. Most feathers (not so much the downy ones) have interlocking barbs on their filaments which have regularly to be ‘zipped’ up by combing them with the bill; especially for water-birds, they need oiling from special oil glands; and they need to be cleaned of parasites. Most of this is done by the individual bird itself, with the bill or sometimes with the foot; but some engage in ‘allopreening’. This is when one bird preens another. This can be part of the bonding rituals between mates. Birds of AFRICAMA House 114 Birds of AFRICAMA House 115