The white-eyed buzzard (''Butastur teesa'') is a medium-sized
hawk
Hawks are bird of prey, birds of prey of the family Accipitridae. They are widely distributed and are found on all continents except Antarctica.
* The subfamily Accipitrinae includes goshawks, sparrowhawks, sharp-shinned hawks and others. Th ...
, distinct from the true buzzards in the genus ''
Buteo
''Buteo'' is a genus of medium to fairly large, wide-ranging raptors with a robust body and broad wings. In the Old World, members of this genus are called "buzzards", but "hawk" is used in the New World (Etymology: ''Buteo'' is the Latin name o ...
'', found in
South Asia
South Asia is the southern subregion of Asia, which is defined in both geographical and ethno-cultural terms. The region consists of the countries of Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka.;;;;;;;; ...
. Adults have a rufous tail, a distinctive white iris, and a white throat bearing a dark mesial stripe bordered. The head is brown and the median coverts of the upper wing are pale. They lack the typical carpal patches on the underside of the wings seen in true buzzards, but the entire wing lining appears dark in contrast to the flight feathers. They sit upright on perches for prolonged periods and soar on thermals in search of insect and small vertebrate prey. They are vociferous in the breeding season, and several birds may be heard calling as they soar together.
Description
This slim and small hawk is easily identified by its white iris and the white throat and dark mesial stripe. A white spot is sometimes visible on the back of the head. When perched, the wing tip nearly reaches the tip of the tail. The ceres are distinctly yellow and the head is dark with the underside of the body darkly barred. In flight, the narrow wings appear rounded with black tips to the feathers and the wing lining appears dark. The upper wing in flight shows a pale bar over the brown. The rufous tail is barred with a darker subterminal band. Young birds have the iris brownish and the forehead is whitish and a broad supercilium may be present. The only confusion can occur in places where it overlaps with the
grey-faced buzzard
The grey-faced buzzard (''Butastur indicus'') is an Asian bird of prey. It is typically in length, making it a small-sized raptor. It breeds in Manchuria, Korea and Japan; it winters in South-east Asia.
It is a bird of open land. It eats liza ...
(''Butastur indicus''), adults of which have a distinctive white supercilium.
Fledgelings are reddish brown, unlike most other downy raptor chicks, which tend to be white.
Taxonomy and systematics
The specific name ''teesa'' is derived from the name in Hindi. The species was described on the basis of specimens collected by James Franklin who placed it in the genus ''Circus'' along with the harriers. The name ''Butastur'' was used to indicate that it appeared to be intermediate in characters to the ''Buteo'' buzzards and ''Astur'', an old name for the sparrowhawks. Molecular phylogeny studies suggest that the genus is a sister group of ''Buteo'' and its relatives within the subfamily Buteoninae.
Distribution and habitat
This species is widely distributed in South Asia, throughout India in the plains and extending up to 1000 m in the
Himalaya
The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 ...
s. It is a resident in Iran, Pakistan, Nepal, Bangladesh, and Myanmar. A form that is possibly of this species has been recorded in the Greater Sundas,
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
but this population is widely disjunct and has whiter and unmarked feathers on the thigh or "trousers" and vent, possibly representing a new form. It is absent from Sri Lanka and is probably absent from the Andamans. It is a summer visitor in northeastern Afghanistan. It is mainly found in the plains, but may go up to 1200 m altitude in the foothills of the Himalayas.
The usual habitat is in dry, open forest or cultivation. They are numerous in some areas, but declining.
A survey in the late 1950s estimated about 5000 birds in the vicinity of Delhi in an area of about 50,000 km
2 giving a density of 0.1 per square kilometre.
Behaviour and ecology
This species is usually seen soaring alone in thermals or perched still. Groups of two or three may sometimes be seen. They have a mewing call or falling whistle (transcribed as ''pit-weer'') that is repeated when pairs are soaring.
They are vociferous in the breeding season.
They feed mainly on locusts, grasshoppers, crickets, and other large insects, as well as mice, lizards, and frogs. They may also take crabs from near wetlands and have been reported to take larger prey such as the
black-naped hare (''Lepus nigricollis'').
The breeding season is February to May. The nest is loose platform of twigs not unlike that of a crow, sometimes placed in a leafless tree. The usual clutch is three eggs, which are white and usually unspotted. Both sexes share nest-building and feeding young; the female alone incubates for about 19 days until the eggs hatch.
A species of endoparasitic
platyhelminth
The flatworms, flat worms, Platyhelminthes, or platyhelminths (from the Greek πλατύ, ''platy'', meaning "flat" and ἕλμινς (root: ἑλμινθ-), ''helminth-'', meaning "worm") are a phylum of relatively simple bilaterian, unsegment ...
has been described from the liver of this species. A species of nematode, ''Contracaecum milvi'', has been recorded in the liver and the stomach while
Acanthocephala
Acanthocephala (Greek , ', thorn + , ', head) is a phylum of parasitic worms known as acanthocephalans, thorny-headed worms, or spiny-headed worms, characterized by the presence of an eversible proboscis, armed with spines, which it uses to p ...
ns, ''Mediorhynchus gibson and M. fatimae'', has been described from the gut of specimens from Pakistan. Protozoa that live in the blood stream belonging to the genus ''Atoxoplasma'' have been isolated. Like most birds, they have specialized ectoparasitic
bird lice
A bird louse is any chewing louse (small, biting insects) of order Phthiraptera which parasitizes warm-blooded animals, especially birds. Bird lice may feed on feathers, skin, or blood. They have no wings, and their biting mouth parts distingui ...
such as ''Colpocephalum zerafae'' that are also known from other birds of prey. A study of power lines in Rajasthan in 2011 found white-eyed buzzards to be the second most common raptor killed by electrocution after kestrels.
Gallery
File:INDIAN WHITE EYED BUZZARD.jpg,
File:White-eyed Buzzard.jpg,
References
Further reading
*
External links
Photos
{{Taxonbar, from=Q1268375
white-eyed buzzard
Birds of South Asia
Birds of the Middle East
Birds of Myanmar
white-eyed buzzard
white-eyed buzzard