
The largest and heaviest of all living birds, the ostrich (Struthio camelus) is instantly recognisable, with its long, bare neck, large body and long, sturdy legs. Despite its relatively small head, it is also notable for having the largest eyes of any land animal, measuring an impressive five centimetres in diameter, and protected by long black lashes. The adult male ostrich has black plumage, with a white tail and primary feathers, and a bright pinkish or blue neck in the breeding season. The female is smaller and is grey-brown in colour, while immature birds resemble the female, but are slightly darker. Four subspecies are recognised, differing mainly in the colour of the neck and legs of the male, and in the amount of feathering on the head. Not needed for flight, the ostrich’s feathers are unusual in that they lack the tiny hooks that hold the feather together, so leaving the barbs (the ‘branches’ of the feather) loose, and giving a very soft, smooth plumage. The ostrich is also the only bird to have just two toes on each rather prehistoric-looking foot. The inner toe is thick and strong, adapted for running, and is armed with a formidable, ten centimetre long claw, which can be used in defence. The ostrich has quite an extensive vocal repertoire, using a variety of whistles, snorts and guttural noises to communicate, as well as other sounds such as bill-snapping. The male also produces a loud “booming” call, which sounds rather like the roar of a lion and is produced during display, or at night when a predator is near. Despite being flightless, the ostrich can run up to 70 km per hour, making it the fastest running bird!