Sandgrouse | |
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Double-banded sandgrouse | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Clade: | Columbimorphae |
Order: |
Pteroclidiformes Huxley, 1868 |
Family: |
Pteroclididae Bonaparte, 1831 |
Genera | |
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Synonyms | |
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Sandgrouse is the common name for Pteroclididae, a family of sixteen species of bird, members of the order Pteroclidiformes. They are traditionally placed in two genera. The two central Asian species are classified as Syrrhaptes and the other fourteen species, from Africa and Asia, are placed in the genus Pterocles. They are ground dwelling birds restricted to treeless, open country, such as plains, savannahs and semi-deserts. They are distributed across northern, southern and eastern Africa, Madagascar, the Middle East and India through to central Asia. The ranges of the black-bellied sandgrouse and the pin-tailed sandgrouse extend into the Iberian Peninsula and France, and Pallas's sandgrouse occasionally breaks out in large numbers from its normal range in Asia.
Sandgrouse have small, pigeon-like heads and necks and sturdy compact bodies. They range in size from 24 to 40 centimetres (9.4 to 15.7 in) in length and from 150 to 500 grams (5.3 to 17.6 oz) in weight. The adults are sexually dimorphic with the males being slightly larger and more brightly colored than the females. They have eleven strong primary feathers and long pointed wings giving them a fast direct flight. The muscles of the wings are powerful and the birds are capable of rapid take off and sustained flight. In some species, the central feathers in the tail are extended into long points. The legs are short and members of the genus Syrrhaptes have feathers growing on both the legs and toes and no hind toes, while members of the genus Pterocles have legs feathered just at the front, no feathers on the toes and rudimentary hind toes raised off the ground. The plumage is cryptic, generally being in shades of sandy brown, grey and buff, variously mottled and barred, enabling the birds to merge into the dusty landscape. There is a dense layer of under down which helps insulate the bird from extremes of heat and cold. The feathers of the belly are specially adapted for absorbing water and retaining it, allowing adults, particularly males, to carry water to chicks that may be many miles away from watering holes. The amount of water that can be carried in this way is 15 to 20 millilitres (0.5 to 0.7 fluid ounce).