General

Hawk-eagles are large to mid-sized, but always powerful raptors with feathered tarsi, long tail and broad wings. They mostly occur in forests or close to forested areas. They are one of the more difficult raptor groups to identify, because of general, and especially age-related, similarity and variability. They are also confusable with other species such as Oriental Honey-buzzard and pale morph first-year Crested Serpent Eagle, and perhaps also with younger fish eagles and Bonelli’s Eagle, and the smaller species also with Jerdon’s Baza. The body plumages of juveniles and adults are remarkably different from each other, and, unlike in most raptors in the area, the body plumage stays of immature type for several plumage generations. Species boundaries vary somewhat in the literature - the southern Indian subcontinent form of Mountain Hawk Eagle is nowadays often split as Legge´s Hawk Eagle, and the western Changeable Hawk Eagle is sometimes separated as Crested Hawk Eagle. Both are presented in separate accounts here.

Distribution

Resident in the Indian peninsula and Sri Lanka.

Geographical variation

Two quite different widespread subspecies, treated here in separate chapters as Crested and Changeable Hawk Eagles. They are sometimes split into different species.

Life cycle

Breeding from February to June in the Indian SC. Mostly moults during the northern summer. Does not moult all flight-feathers in a single year.

General

Crested/Changeable Hawk Eagles are somewhat smaller than Mountain/Legge´s Hawk Eagles, with the female distinctly larger than the male as well as having stronger feet. Often seen perching in trees. Larger and more powerful than Oriental Honey-buzzard, but the difference in the field is not always evident. Wings still broader, with especially the base of the wing broad and bulging because of long secondaries, with seven fingers (six in Oriental Honey-buzzard), stronger bill and head, as well as feathered, longer and stronger legs. There are also several differences in the plumage patterns.

Adult

Brownish head, moustachial stripe not as distinct as in Mountain Hawk Eagle, pale throat and often a distinct mesial stripe. Long crest formed by some long, mostly black feathers (similar to Mountain Hawk Eagle, but different from Changeable limnaeetus). Dark brownish streaking on whitish background on the breast (adult Mountain Hawk Eagle has barred underparts, some adult female Oriental Honey-buzzards have similar streaking, but many pale Oriental Honey-buzzards show at least some barring on the underparts and a dark necklace, unlike Changeable H-E). Lower underparts, including the trousers, are often almost uniform dark brownish, but may also show some barring. Remiges densely and regularly barred, with about four internal bars on the secondaries, and a slightly broader terminal band (similar to adult female Oriental Honey-buzzard, but internal bars more evenly spread, while adult Mountain Hawk Eagle has blacker and broader bands). The bases of the primaries form the palest parts of the underparts. The tail shows two or three internal bars (not very unlike adult female Oriental Honey-buzzard). Iris orange-yellow.

First-year

Long blackish crest. In fresh plumage shows a cinnamon tinge on head and underparts, including most of the underwing-coverts, which soon fades to uniform pale however, in some almost white. Only some subdued brownish patterning, or with light streaking on the upper breast, with the most discernible pattern on the underparts. Greater underwing-coverts show some black barring. Upperpart feathers have pale buffish uniform fringes, which on the median coverts often merge to form a larger pale buffish area. Uniform pale rump. In flight from above from a distance shows a pale head, pale uppertail-coverts and a largish pale area on the median upperwing-coverts, as well as a pale crescent at the center of the hand - near the bases of the fingers. The broader terminal band on the secondaries and primaries is indistinct compared to that in adults, and there is some variation and the difference may be slight, but the band is not as broad and clear-cut as in adults. Especially the outermost primaries have more extensive dark tips with a less clear-cut border than in adults. Uniformly densely barred tail with about 5 bars, with the terminal band not much broader than the internal bars (adults have a broader terminal band and fewer internal bars). Iris quite pale but not yellowish. For separation from young Mountain/Legge´s Hawk Eagles, see the chapter for first-year Mountain Hawk Eagle. Very similar to young Changeable, which see.

Subadult

The body plumage is still extensively pale after the first moult, the adult aspect is acquired slowly and variably, and in many individuals this will take about three years. During the second year, underparts are typically still very pale, but with some bold black streaks. The greater underwing coverts are barred black. From two to up to half the outer primaries are still retained juvenile feathers in second-year birds, while in third-years some outer primaries and some secondaries are still juvenile. The difference in the pattern of juvenile and post-juvenile wing-feathers are modest in this species - on juvenile feathers the outermost dark band is narrower and less distinct, and the tips of the outermost primaries are more extensively dark - and the 2g feathers are very similar to the later ones, which makes ageing in the field more difficult. The 2g flight-feathers may show an intermediate pattern, with somewhat more extensive and less clear-cut dark tips than in adults.

Distribution

Resident at the base of the Himalayas, parts of SE Asia and the Thai-Malay peninsula.

Geographical variation

This is the northern and eastern subspecies, see Crested Hawk Eagle.

Life cycle

Breeding from January to May in the Thai-Malay peninsula. Mostly moults during the northern summer. Does not moult all flight-feathers annually.

General

Similar to Crested Hawk Eagle, which is normally treated as conspecific, and differs from other species in the same way. Occurs in the same areas as Mountain, Blyth’s and Wallace’s Hawk Eagles and often difficult to separate from them.

Adult

Similar to Crested Hawk Eagle adults, but does not have a true crest. The neck feathers are only somewhat elongated, but there are intermediates in the Himalayas and northern India. Differences in underpart colouration separates the majority of peninsular Indian and SE Asian birds from each other, but Himalayan birds are again intermediate. The head is lighter grey (darker and more brownish in Crested), and trousers and lower underparts are lighter and more clearly barred than in Crested (which normally has uniform brown lower underparts - this area can be lighter, but if so, less barred). The most typical pattern is similar bold streaks on the whole of the breast-belly area. A very few individuals show uniform brown rear underparts, and these birds are often also otherwise darker than in normal birds, and may be inseparable from typical Crested on colouration. Underwing-coverts are less streaked, although with some overlap, with greater underwing coverts barred black in both subspecies. The upperparts are similar. The wing feathers are quite densely and regularly barred black - with about five internal bars, and a broader terminal band, and the primaries show unbarred pale bases. Outermost primaries typically rather darker, and barring may be difficult to discern (in Crested, typically paler outer primaries with distinct barring). The tail shows about three black internal bars and a distinctly broader black terminal band, with a pale area between the latter and the next black bar, being broader than the other pale areas (the tail is similar in both subspecies). A black morph occurs from West Bengal eastwards and is mostly blackish on the underparts and underwing-coverts, and with very indistinctly barred remiges and rectrices, with the bases of these feathers paler than the tips, and even dark eyes (this combination is unlike any other regional raptor species. Black Eagle is roughly similar, but with different behaviour, yellow cere and gape, shorter legs, longer wings, different wing-shape, narrow whitish barring on flight-feathers and a whitish “half-moon” at the bases of the undersides the the outer primaries).

First-year

Crest very short or lacking, otherwise very similar to Crested Hawk Eagle, which see. On average, somewhat paler than Crested, with a paler head, more often totally white underbody, with the uppertail-coverts forming a whitish patch (typically pale but not whitish in Crested). The barring on the flight-feathers often somewhat narrower and less distinct. The black morph already shows in juveniles. For separation from young Mountain/Legge´s Hawk Eagles, see the chapter for first-year Mountain Hawk Eagle.

Subadult

Ageing as in Crested Hawk Eagle, which see.

Distribution

The nominate in the Himalayas, parts of SE Asia and the Western and Eeastern mountains of China, orientalis in Japan and adjacent coastal areas of Russia, possibly also Northern China. Chinese birds, especially in Sichuan and northwards, may be intermediate between orientalis and the nominate.Fokiensis is described from the eastern mountains of China, but normally not accepted nowadays.

Geographical variation

Orientalis is larger and paler than the nominate with a short crest only. The barred area on the underparts is restricted in adults also, with a pale area reaching from the upper breast, along the middle of the underbody, and almost up to the legs. ‘Fokiensis’ is described as similar to the nominate, but smaller, and perhaps with a shorter crest.

Life cycle

The breeding season is from late winter to early summer, later in the northern parts of the distribution area.

General

A large eagle with very broad wings. Always shows a crest (which the nominate of Changeable Hawk Eagle does not), but this is not visible in flight. Somewhat larger than the similar Changeable/Crested, but this is seldom of use in identification. The body is thicker, but some young birds may be sleeker than the norm, and the head is less protruding. The wings are broader, but the difference may be slight. In very good views, and more often in photos, it is possible to see that the feathering on the legs continues to the base of the toes so that the toe division looks feathered (in Changeable/Crested Hawk Eagle the feathering stops as a straight line just above the toe divisions).

Adult

Contrasting black moustachial and mesial stripes, with the whole head often darker-looking than the rest of the underparts. The belly prominently barred, as are the greater coverts, while the breast is variably streaked. (Oriental Honey-buzzard may show similar barring on the underparts, but the structural differences should be evident, as is the type of barring on the remiges). The remiges show three internal bars and a trailing band, which is only slightly broader (in adult Changeable, the inner bars are distinctly narrower and the first intervening pale area is broader than the other pale areas). The tail pattern is similar to the secondary pattern but the terminal band is quite distinctly broader than the other bars (inner bars of Changeable Hawk Eagle are narrower). Orange iris.

First-year

Can be difficult to separate from young Changeable/Crested Hawk Eagle, if the crest is not seen, and it is usually not visible in flight, and in any case, the crest does not separate it from Crested Hawk Eagle. Quite uniform pale head and underparts, with the moustachial and mesial stripes mostly still evident, but the head may be almost all pale (Changeable has no broad moustachial stripe). There is some tawny colouring on the underbody and underwing-coverts, if not too bleached (juv Changeable is not tawny, but rather whitish, while subadult can be tawny). Barring on underbody usually present, even if subdued, especially on trousers and legs, with these being also often slightly darker overall (palish, almost whitish and unmarked in juvenile Changeable, with barring rarely visible at that age, more often when older, but still less extensive). Remiges and tail densely and evenly barred with dark bars about as broad as the pale intervening bars (in young Changeable, the pale bars are broader and, on the tail, the outermost dark band is broader than the others and also the next pale bar is slightly broader than the other ones). Compared to adults, 1g secondaries and inner primaries are somewhat more densely barred and with a less distinct dark subterminal band than in adults, and the outer primaries show a broader dark tip with less distinct border to the outermost pale band. On the upperwing, the palest part of the remiges area tend to be the white-barred inner primaries (in Changeable, the palest part are the bases of the outer primaries, which form a whitish crescent – this difference holds true in adults also).

Subadult

As in Changeable Hawk Eagle the body plumage remains of immature type for several years. In older subadults, all the flight feathers may be of adult type while the body plumage still is largely immature. Species identification at this stage is possible by combining adult and juvenile characters - for example, the differences in the adult-type barring on the flight-feathers.

Distribution

Western Ghats of India and Sri Lanka.

Geographical variation

Life cycle

Breeds during the northern winter.

General

The southern counterpart of Mountain Hawk Eagle, sometimes treated as a subspecies of it. Does not occur in the same area with Mountain Hawk Eagle, but extensively overlaps with Crested Hawk Eagle, and they are readily confusable. Quite similar to Mountain Hawk Eagle, but with longer toes and larger bill. Especially the toes and claws look almost disproportionally strong, and the tarsus is very thick (which are useful distinctions from Crested Hawk Eagle too, when perching birds are seen, but not visible in flight. The body of Crested is also somewhat slimmer).

Adult

Compared to Mountain Hawk Eagle, paler head, narrower gular stripe and narrower and shorter streaks on upper breast. Separated from Crested Hawk Eagle by barred underparts (Crested is boldy streaked with darker rear underparts), broad and distinct dark internal bars to flight-feathers (in Crested the internal bars are narrower and sparser.)

First-year

No known colour differences from Mountain Hawk Eagle. Separated from Crested the same way as Mountain: underparts tawny (whiter in Crested), some marks of barring on underbody often present, flight feathers densely and evenly barred, with the dark bars about as broad as the pale ones (in young Changeable, the pale intervening bars broader). On the upperwing, the palest area is the inner primary window (not the bases of the outer primaries, see 1y Mountain Hawk Eagle for more information).

Subadult

Maturing takes several feather generations. The underparts barring starts to emerge rather early, making separation from Crested Hawk Eagle easier.

Distribution

Thai-Malay peninsula.

Life cycle

Winter-breeder, the young fledge in February-March. Flight-feather moult mostly during the late northern summer and autumn.

General

Smallish but strong forest eagle. More montane than Wallace’s Hawk Eagle, but often the two species occur close to each other. Adults distinctive, but colouration resembles some Oriental Honey-buzzards, which see. The shape differs from Oriental Honey-buzzards as in Wallace’s, which see. Juveniles similar to the corresponding plumage of Wallace’s and useful distinguishing features not well known.

Adult

Distinctive: orange eyes and white throat with black central stripe, with the rest of the head and the long crest black. White upper breast with some strong black streaking or blotching, belly to under tail coverts as well as under wing coverts strongly barred black and white, upperparts blackish. Remiges show a distinct black subterminal bar and two internal bars on the inner feathers and three on the outer feathers. The bars are also visible on the upperwing with a somewhat paler area on the upper side of the outer wing. The tail shows a broad, pale central bar, with the tip and base blackish. The central bar is also contrastingly pale when seen from above. Some Oriental Honey-buzzards are similarly coloured with white and black, but Blyth’s Hawk Eagle has a stronger head, longer and feathered legs and proportionally somewhat shorter and slightly more tapering wings, and lighter, streaked breast and less solidly dark trailing edge to the wing. (Oriental Honey-buzzard also shows smudgy internal barring on the flight-feathers, typical of the genus Pernis). Also see Wallace’s. The plumages of both sexes similar, but females are noticeably larger.

First-year

Very different-looking from adults, but often difficult to separate from juveniles of other hawk eagles. Very similar to young Wallace’s which see. Tawny, almost coppery head and black crest with white tip (Changeable Hawk Eagle is not crested). Quite dark eyes at first, which turn yellow. Almost unpatterned tawny underparts when fresh (Changeable whitish), but bleaching paler, although still retaining the coppery tinge. Also the upperparts are browner than in adults, with whitish scaling when fresh. Juvenile secondaries and primaries show a less distinct black subterminal band than adults and the inner bands are more evenly located than in adults. The inner bars are quite narrow (being somewhat broader in juvenile Changeable Hawk Eagle). Typically also the outer primaries are barred (almost uniformly darkish in many juvenile Changeable), the tail is sparsely barred with three narrow black bars visible on uppertail (Changeables with a juvenile tail have more, as well as narrower bars, and the pale area inside the two outermost bars is broader than the other pale areas).

Subadult

Acquires distinctive black barring, or at least many black feathers, on the underbody during the first moult, and the second set of flight-feathers is of adult type. Subadults can be aged when they show a mixture of adult and juvenile type flight feathers. The emerging black pattern should enable separation from Wallace’s of any age (in Wallace’s the darker patterning would emerge as streaks on the breast and suffused barring on the thighs and lower underparts), while the second set of rectrices in Blyth’s already only shows two black bands and a broad pale central band (Wallace’s has at least three dark bands in any plumage).

Distribution

Thai-Malay peninsula.

Geographical variation

No described geographical variation, but the mainland Asian adults are on average darker, with more extensive, clear-cut and blacker barring underneath than the Bornean birds.

Life cycle

Winter-breeder, the young fledge in February-March. Some irregularities, however, with fresh juveniles sometimes seen in late northern autumn. Moult inadequately known, but presumably during the northern summer and autumn, before the breeding season.

General

Resembles Blyth’s Hawk Eagle, but slightly smaller. Generally lives at lower elevations, while Blyth’s is more of a mountain species. The shape and colours are broadly similar to Jerdon’s Baza, but the neck is longer and the bill stronger, and the secondaries are not as bulging, with a broader wing base, and the legs are longer, stronger and feathered. Compared to Oriental Honey-buzzard, looks somewhat smaller in direct comparison, especially because of shorter wings. Wings are broader than in that species, with a more bulging trailing edge and a rounder tip which makes it difficult to count the fingers (Oriental Honey-buzzard has six longer and easily countable fingers). The body is thicker and the head larger and the tail is more square-shaped. When higher, soars with wings in a low V-shape, but often flies inside the forest, showing much resemblance to a large Accipiter hawk.

Adult

Mostly tawny-brown head and blackish crest (adult Blyth’s shows distinctly blacker sides to the head, with the sympatric subspecies of Changeable lacking a long crest, while Mountain has an even somewhat longer crest). Often the colour of the head looks contrastingly warm brown compared to the general colouration. Yellowish eyes (orange in adult Blyth’s). There is blackish or brownish streaking on the breast and barring below the streaking, and trousers also barred - the general pattern is therefore not unlike Blyth’s, but belly and leg barring narrower and browner (in Blyth’s the patterning is almost black. Jerdon’s Baza has a more distinct mesial stripe and a regularly barred underbody, Changeable shows a less barred, mostly streaked underbody). Upperparts brownish (but may approach the blackness of Blyth’s). Around three clear-cut black bands traverse the secondaries and primaries (as in Blyth’s. In Jerdon’s Baza the trailing band is especially broad and distinct, while Changeable shows more bars – about three in addition to the trailing edge). The tail shows three black bands (two in adult ´) with the pale intervening areas not very contrasting on the uppertail (more contrasting in Blyth’s). Underwing-coverts almost unpatterned (Jerdon’s Baza has broadly barred underwing coverts, while in adult Changeable they are spotted or streaked). The plumage is similar between the sexes, but females are larger.

First-year

First-years show quite a different plumage aspect compared to adults. The head is palish, with a black, white-tipped crest. Dull brownish eyes (yellow in adults). Almost unpatterned pale tawny underparts with some barring on thighs at the most. Whitish scaling on upperparts when fresh, but this will disappear with wear. Juvenile primaries show less clear-cut darkish tips than those of adults. The tail has three or four narrow brownish bars, which are less clear-cut than the three broader bars in the tail of the adults. Very similar to same-age Blyth’s and distinguishing features not well known. Wallace’s is somewhat paler and tawny with sandy tones (Blyth’s is almost coppery), but bleaching will affect these colours. Also, Wallace’s shows paler fringes to the upperparts and the pale tips to the greater coverts are broader, while Blyth’s tend to have narrower fringes, and sometimes gives an almost spotted impression on the upperparts. Wallace’s tail has fewer and broader dark bands than at least most Blyth’s. Separation from young Changeable Hawk-eagle as with Blyth’s, which see.

Subadult

The second set of flight feathers seems to be similar to those in adults (as in Blyth’s), but in contrast to Blyth’s, the body plumage matures slowly. First post juvenile body feathers are not fully matured: on underparts there are variable streaks and bars of adult type, but they are not as extensive and bold, and they still show a rufous tone.