Upland buzzard

The upland buzzard (Buteo hemilasius) is a species of bird of prey in the family Accipitridae. The largest species of the Buteo genus, this buzzard lives in mountainous grassy and rocky areas in areas of Central Asia, northern South Asia and East Asia from Kazakhstan to Korea. The upland buzzard is migratory but typically covers a short distance apparently to avoid snow cover that may hamper prey capture. This species primarily subsists on small mammals but does not shun alternate prey from small to large birds and insects. This little known raptor has a large range, and though generally uncommon, it is not thought to be rare or declining as a species. As a result it is classified as least concern by the IUCN.

This is the largest buzzard and the largest member of the genus Buteo in the world based on total length and wingspan. However, it is roughly equaled in bulk by the North American ferruginous hawk (Buteo regalis), which is also only marginally smaller going on mean standard measurements. The total length of the upland buzzard is 57 to 72 cm (22 to 28 in) and wingspan is 143 to 161 cm (4 ft 8 in to 5 ft 3 in). Body mass is known to range from 950 to 1,400 g (2.09 to 3.09 lb) in males, with three averaging 1,168 g (2.575 lb), and from 970 to 2,050 g (2.14 to 4.52 lb) in females, with seven averaging 1,581 g (3.486 lb). The average size of 14 upland buzzards in the Tibetan Plateau was 639 mm (25.2 in) in length, including a tail of 289 mm (11.4 in), a smallish culmen of 30 mm (1.2 in), a tarsus length of 86 mm (3.4 in) and a body mass of 1,557 g (3.433 lb). The Upland buzzard is conspicuously large for a Buteo, with long wings and a relatively long tail, and fairly eagle-like compared to related species. There are both pale and dark morphs. The pale morph is generally beige and earthen dark brown in colour. This morph bears a lightly marked whitish colour with a variable ochre wash to the head and nape with the chest generally appearing purest whitish. On pale morphs, the whitish chest is contrasted with dark brown areas widely but irregularly distributed across the lower breast and abdomen. The flanks and belly are similarly dark, while the tail is greyish with dark sides and prominently dark bands, with a heavier sub-terminal band. The coverts on perched buzzards can appear lighter brown than elsewhere. In flight on pale morphs, the major coverts are variable, appearing somewhat streaky brown, contrasted with a very strong blackish patagium mark. The flight feathers appear whitish with a variable amount of dark barring leading into the blackish wingtips and trailing edges. Dark morph upland buzzards are almost entirely solid black-brown throughout the body. with the flight feather pattern similar to pale morph but darker apart from the flight feathers. The call of the upland buzzard is a prolonged nasal mewing, not dissimilar to that of the common buzzard (B. buteo), although it is said to vocalize less than that species. The "trousers" are heavily feathered brown, often covering at least three-quarters of the legs. Despite individual variations, these buzzards are more insulated on their legs than other Buteo, apart from the ferruginous hawk and rough-legged buzzards (B. lagopus) which both have feathering extending along their tarsi.

The upland buzzard is fairly similar in plumage to others buzzards, and may need to be distinguished from the overlapping species of long-legged buzzards (B. rufinus), Himalayan buzzards (B. reflectus) and eastern buzzards (B. japonicus). The Himalayan species in particular is often found is similar in distribution and in similar habitats at high elevations. The upland species is known to be difficult to distinguish from the related long-legged buzzard, and the two species are often misidentified for each other. However, it is said it can be told from the long-legged buzzard by being slightly larger and lacking the warmer, sometimes rufous tones (rather than earthen brown) of that species. However, the extent of patterns are roughly corresponding on both the upland and long-legged buzzard as well their proportions and size broadly overlaps between the two. Usually the long-legged buzzard tends to occur at lower elevations. However, distant flying buzzards are sometimes considered to be too similar to be identifiable between these species, especially darker individuals. The other buzzards are conspicuously smaller, with shorter proportions to their much smaller wings and shorter tails. Both Himalayan and eastern buzzards are also differently marked, usually appearing paler bellied apart from a belly band and stipling to the flanks with less strongly contrasting patterns on the wing on the coverts and flight feathers. Dark morphs of the respective buzzard species are more similarly marked but the upland buzzard can be distinguished by its size and proportions, excepting the dark morph long-legged buzzard which is practically indistinguishable.