Vertebrate Zoology - V. M. Konstantinov 2011

Chordates
Terrestrial, or Tetrapod, Vertebrates — Vertebrates with Embryonic Membranes
Class Birds — Subclass Fan-tailed Birds, or True Birds — Superorder Neognathae, or Typical Birds — Order Columbiformes

The order Columbiformes comprises two suborders: Columbae (doves and pigeons) and Pterocletes (sandgrouse), whose representatives differ sharply from one another.

Doves and pigeons are strictly diurnal birds of robust build, featuring a short beak equipped with a cere. Their nostrils are covered by small fleshy opercula. Modern pigeons have well-developed wings and a rapid flight. The uropygial gland is poorly developed or absent. The crop is well developed and, during the breeding season, secretes 'crop milk' used to feed the nestlings. The young are altricial. The clutch consists of two, rarely one egg, and both the female and male participate in incubation. They are monogamous. Distributed almost globally, excluding polar regions, they are most abundant in the Malay Archipelago and the Australasian zoogeographic region. The total number of species is 290, with eight species found in Russia, for example: the stock dove (Columba oenas), the wood pigeon (C. palumbus), the rock dove (C. livia, see Fig. 148), and the European turtledove (Streptopelia turtur).

These birds are predominantly inhabitants of forests, less frequently of mountains, or associated with human settlements. Their diet is diverse, gathered mainly on the ground. A few species of tropical pigeons are frugivorous. Most species are sedentary. In the past, the islands of Mauritius, Réunion, and Rodrigues (near Madagascar) were home to the dodo (Raphus), a large, flightless, terrestrial pigeon weighing up to 20 kg, which was exterminated by humans in the 18th to early 19th centuries. In North America, the passenger pigeon (Ectopistes migratorius) was driven to extinction by 1914. A wide variety of domestic breeds (around 200 breeds) have been developed through the domestication of the rock dove (Columba livia). Domestication apparently occurred around 3,000 to 5,000 years BC.

A relatively recent newcomer to towns and villages in European Russia is the Eurasian collared dove (Streptopelia decaocto). At the beginning of the 20th century, its range was restricted to the Eastern Mediterranean; however, it rapidly expanded westward and northward across Europe, and by the early 1970s, it had become a common bird in Western Europe and Great Britain (except for Spain, Yugoslavia, and most of Scandinavia). In Russia, it is actively expanding northward and eastward, having reached the Volga region and Ciscaucasia, and has colonized Kazakhstan, the Altai, and Central Asia. It has also been acclimatized in Japan and the USA. It nests in trees.

Sandgrouse (Pterocletes) are medium-sized birds that outwardly resemble pigeons; unlike pigeons, however, they inhabit the deserts and steppes of Africa and Asia rather than forests and mountains. Their chicks are precocial rather than altricial like those of pigeons. They nest exclusively on the ground, with a clutch of 3 to 4 eggs. Their food is gathered solely on the ground. They are exceptionally fast flyers with long, sharply pointed wings. Their feet are small, occasionally with fused toes. There are 16 known species. In the deserts of Russia, two species of sandgrouse occur — the black-bellied sandgrouse (Pterocles orientalis) and the spotted sandgrouse (Pt. alchata) — along with a highly peculiar species known as Pallas's sandgrouse, or saza (Syrrhaptes paradoxus). Pallas's sandgrouse lacks a hind toe; the three front toes are feathered above and fused together, forming a Structure resembling a beast's paw. The claws are broad and blunt. The tail is very long and composed of narrow feathers (see Fig. 148). Pallas's sandgrouse is well known for its mass irruptions, during which flocks of these birds have appeared in the European part of Russia and further west as far as France and Great Britain inclusive, and eastward as far as Khabarovsk. Migrations of this scale were recorded in 1863, 1883, 1888, and 1908, coinciding with periods of mass reproduction.