Seasonal life of birds, oasis and desert birds

The most common birds in oases and settlements are passerines: swallow, rook, starling, nightingale, sparrow, tit, crow. They make up more than half of all bird species. The male is usually bigger and more colourful than the female, or sings beautifully. The swallow has a long forked tail, narrow wings, short legs and a flat beak that opens wide; it catches insects in the air, flies nearly all day, builds a mud nest and lays 4–6 eggs. It eats thousands of pest insects in fields and houses and is very useful. Many passerines eat everything: the starling helps by eating insects but harms ripe fruit. Even grain-eaters feed their chicks with insects. The pigeon-like order includes the rock dove and the collared dove. The rock dove is the ancestor of domestic pigeon breeds, nests on cliffs and attics of abandoned buildings and eats grain and seeds; the collared dove lives in pairs and raises several broods a year. In open steppe and desert there is nowhere to hide, so desert birds seek food on the ground, nest on the ground, have long legs and necks and earth-coloured plumage – helping them spot enemies from afar and hide. The houbara bustard, of the bustard order, runs fast, eats plants, insects, lizards and small rodents, and lays eggs in a ground hollow. It has declined and is listed in Uzbekistan’s Red Book. The ostrich-like birds (African ostrich, rhea, emu) are the largest birds: they cannot fly, have no keel, their wing feathers form no vane, and they run fast (about 60–70 km/h) on strong legs with thick skin; the African ostrich has only two toes on each foot. The African ostrich is about 2.5 m tall and weighs over 100 kg; its egg weighs up to 1.5 kg.