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The fork-tailed drongo, also called the common drongo, African drongo, or savanna drongo (''Dicrurus adsimilis''), is a drongo, a type of small passerine bird of the Old World tropics. The species was earlier considered to cover Asia, but the Asian species is now called the black drongo (''Dicrurus macrocercus''). They are members of the family Dicruridae. The fork-tailed drongo is a common and widespread resident breeder in Africa south of the Sahara. These insect-eating birds are usually found in open forests or bush. Two to four eggs are laid in a cup nest in a fork high in a tree. These are aggressive and fearless birds, given their small size, and will attack much larger species, including birds of prey if their nest or young are threatened. The male is mainly glossy black, although the wings are duller. It is large-headed and has the forked tail which gives the species its name. The female is similar but less glossy. The bill is black and heavy, and the eye is red. The fork-tailed drongo is 25 cm long. It has short legs and sits very upright whilst perched prominently, like a shrike. It flycatches or take prey from the ground and is attracted to bush fires. The call is a metallic ''strink-strink''. The fork-tailed drongo in Africa are capable of using deceptive mimicked alarm calls to steal food from birds and animals such as meerkats.〔Tom Flower, Fork-tailed drongos use deceptive mimicked alarm calls to steal food Proc. R. Soc. B rspb20101932; published ahead of print November 3, 2010, doi:10.1098/rspb.2010.1932 1471-2954, http://rspb.royalsocietypublishing.org/content/early/2010/10/27/rspb.2010.1932.full〕 The subspecies ''D. a. modestus'' (Príncipe) together with ''D. a. coracinus'' and ''D. a. atactus'' (Bioko and mainland west and central Africa from Guinea east to western Kenya and south to Angola) is usually split as a separate species, the velvet-mantled drongo ''D. modestus'', (Hartlaub, 1849). == Behavior == Observations show that the fork-tailed drongo in Africa are capable of using deceptive mimicked alarm calls to steal food from birds like pied babblers and animals such as meerkats. Tom Flower observed that fork-tailed drongos spend a quarter of their time following other animals. Sometimes when a predator is approaching, drongos act as sentries and warn their neighbours with genuine alarm calls. But drongos also earn quarter of their daily calories by sounding a false alarm, when the other animal finds food. When the meerkats and babblers flee from the non-existent predator, drongo steals their food. Researchers have considered the possibility that these drongos possess theory of mind, not fully shown in any animal other than humans, but doubt this capability.〔Tom Flower, Fork-tailed drongos use deceptive mimicked alarm calls to steal food, Proc. R. Soc. B rspb20101932; published ahead of print November 3, 2010, doi:10.1098/rspb.2010.1932 1471-2954, http://rspb.royalsocietypublishing.org/content/early/2010/10/27/rspb.2010.1932.full〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Fork-tailed drongo」の詳細全文を読む スポンサード リンク
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