Mourning Drongo
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| Mourning Drongo | ||||||||||||
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Mourning Drongo ( Dicrurus adsimilis ) |
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| Dicrurus adsimilis | ||||||||||||
| ( Bechstein , 1794) |
The fork-tailed drongo ( Dicrurus adsimilis ) is a species of bird from the family of Drongos .
The species was previously regarded as conspecific with the King Drongo ( Dicrurus macrocercus ).
It occurs in Africa in Ethiopia , Angola , Botswana , Democratic Republic of the Congo , Eritrea , Gabon , Guinea , Cameroon , Kenya , Republic of the Congo , Lesotho , Malawi , Mauritania , Mozambique , Namibia , Zambia , Senegambia , Zimbabwe , Somalia , Sudan , South Africa , Swaziland , Tanzania , Chad , Uganda , Central African Republic .
The distribution area includes tropical or subtropical wooded habitats except dense forest up to 2200 m altitude.
description
Mourning drongos are 23–26 cm tall, weigh 48–53 g ( nominate form ) and have shiny black plumage, the head, top and chest are shiny blue-green. In female animals, the gloss is not so pronounced. Their strong, slightly curved beak with vibrissae is black and their iris is red. Their tail, which forks into two ends towards the end of the tail and at 115–126 mm, makes up almost half of the total length, is characteristic. The arm wings are brownish, the underside of the wing is clearly paler in flight. Strange-looking double-forked tails may be seen during moulting. The young bird is dark brown with small reddish spots on the ends of the feathers, the beak is even less curved, the iris is brown. Overall, the plumage is not shiny, the underside is paler.
voice
The male is described as very happy to sing, often the first bird in the morning and the last in the evening. The call is a very variable mix of rough, nasal, sharp tones.
Geographic variation
The following subspecies are recognized:
- There. divaricatus ( MHC Lichtenstein , 1823), [incl. jubaensis] - Southwest Mauritania, Senegambia and Guinea to Cameroon, Chad, Sudan, Ethiopia, Eritrea and Somalia, south to Central African Republic, Democratic Republic of the Congo, northern Uganda and Kenya. Includes the subspecies D. a. jubaensis van Someren , 1931
- There. apivorus Clancey , 1976 - English Clancey's Drongo - southeast Gabun and Congo bordering, Angola, Zambia, Namibia, Botswana and northern South Africa.
- There. fugax W.KH Peters , 1868 - Uganda, Kenya and Tanzania (including Zanzibar ), Zambia, Malawi, Mozambique, Zimbabwe, Botswana, northeastern South Africa and eastern Swaziland
- There. adsimilis ( Bechstein , 1794), nominate form - west of Swaziland, Lesotho lowlands, and east and south of South Africa
Way of life
The breeding season is between March and September north of the equator and between September and January south of it. They lay two to four eggs in a bowl-shaped nest that is built in a fork at the top by trees. The eggs are very variable in their color. They range from white to pink or salmon in color with a brown or reddish brown speckle. The nests are more often parasitized by the African cuckoo. The eggs that the African cuckoo lays are also very variable and can sometimes hardly be distinguished from those of the weeping drongo.
They feed mainly on insects, but also on fish swimming on the surface or the prey of other birds that they steal from them. Another tactic for obtaining food is to chase larger animals roaming around in the African bush such as rhinos, elephants, giraffes, etc. The large mammals scare away not inconsiderable amounts of insects when walking through tall grass and grazing trees, which benefits the weeping drongo. In this way, they are presented with a wide range of food in a convenient way. Mourning drongos are therefore often seen in the vicinity of herds or family groups of the mammals mentioned above.
Hazardous situation
The stock is not considered to be at risk ( least concern ).
Kleptoparasitism
Mourning drongos have developed a tactic to deceive meerkats and magpie thrush and steal their prey. To do this, they often emit species-specific calls that are intended to warn of approaching birds of prey and to which other species such as magpie or meerkats also react. However, after a certain time the animals get used to the false alarm signals and no longer react accordingly. Tom Flower from the University of Cambridge in the South African Kalahari Desert observed that the mourning drongos then imitate the warning call of various other birds so deceptively real that in most cases their target objects actually startle again, seek cover and do so in at least 50 percent of the cases Cases leave their prey behind, which is subsequently picked up by the weeping drongos - a behavior known as kleptoparasitism . At the same time, the alarm giver also gained an advantage over conspecifics who were in the vicinity, because these too often sought protection in bushes and trees. Flower found out that voice imitation is worthwhile for the mourning drongos, because this way they can get around a quarter of their food - with minimal effort.
Mourning drongos are not fearful and are very aggressive. They do not shy away from attacks on larger birds, including birds of prey, if, for example, their nest is threatened.
Web links
- Dicrurus adsimilis in the endangered Red List species the IUCN 2015 Posted by: BirdLife International, 2012. Retrieved on February 2, 2016th
- fotocommunity.de A very nice picture of a funeral drongo
- Videos, photos and sound recordings of Dicrurus adsimilis in the Internet Bird Collection
Individual evidence
- ^ Trauerdrongo , in Avibase - The World Bird Database
- ↑ a b c d e Handbook of the Birds of the World
- ^ A b c T. Stevenson, J. Fanshawe: Birds of East Africa. Kenya, Tanzania, Uganda, Rwanda, and Burundi. Princeton University Press, 2002, ISBN 978-0-691-12665-4 .
- ↑ Oiseaux.net
- ↑ Orioles, drongos, fantails
- ↑ J. Fuchs, J. Fjeldså and RCK Bowie: Diversification across major biogeographic breaks in the African Shining / Square-tailed Drongos complex (Passeriformes: Dicruridae). In: Zool. Scripta 2017, doi: 10.1111 / zsc.12191.
- ^ Paul A. Johnsgard: The Avian Brood Parasites - Deception at the Nest . Oxford University Press, Oxford 1997, ISBN 0-19-511042-0 , p. 192.
- ↑ Redlist
- ↑ T. Flower: Fork-tailed drongos use deceptive mimicked alarm calls to steal food. In: Proceedings of the Royal Society B Biological Sciences. Volume 278, 2011, pp. 1548-1555. doi: 10.1098 / rspb.2010.1932 .