General

Snake Eagles in Eurasia are two species specialised eating snakes and other reptiles. Both are large, broad-winged eagles. The two species are in different genera, and look very different, but are still quite closely related.

Distribution

Breeding widely from SW, S and E Europe to Mongolia and mostly wintering in the Afrotropics. Sedentary on the Indian peninsula, with also some northern birds wintering there. Scarce passage migrant in SE Asia.

Life cycle

Summer breeder, long-distance migrant except on the Indian SC, where sedentary. Moults both in summer and winter.

General

Mid-sized or even largish eagle having whitish general colouration with dark spots. Within the region there are no big confusion problems, although the palest of Hawk Eagles Nisaetus and young Crested Serpent Eagles may have some resemblance, as some pale buzzards. Larger, longer-winged and stronger-bodied than any Buteo - buzzards, and with six protruding fingers. The tail is almost square and comparatively short. When perching, looks large-headed and with brownish upperparts, whitish underparts. Unfeathered legs (unlike Hawk Eagles). Patrols slowly over open areas and stops to hover now and then. Wing-beats distinctive: slow and somewhat sluggish but strong. When gliding, often has arm slightly raised and hand level.

Adult

Almost uniformly greyish-brown head and upper breast form a hood which contrast strongly to whitish, brown-barred and spotted underbody and underwings. The hood is most often quite distinct and a good identification character, but in some it is more streaked with white and less contrasting. Those with a more uniform dark hood are older females. (Buteos normally lack a hood and even the palest of them tend to have darker belly or thigh patches.) Carpal area patterned like coverts. (Buteos tend to have this area dark, forming a carpal patch.) Upperparts mostly brown and with paler patches on the covert area (but less distinct and clear-cut than in Booted Eagle or Milvus kites). Remiges with dark trailing edge and two, narrow dark lines. Tips of primaries dark, the feathers becoming darker towards the outermost tip (even the palest of Buteos and honey-buzzards have more distinctly and extensively black fingers), tail has a distinct trailing band and two internal bars (unlike any Buteo or Nisaetus). Orange-yellow irises, often quite striking against the area of dark hood.

First-year

Superficially like adult: pale and dark-spotted. Uniform, neat plumage with regular pattern on both upperparts and underparts. Hood is more streaked and less distinct than in adult, but on average, more distinct than in subadults. Body patterns are also slightly less clear-cut and browner than in adult, as are the bars on the remiges.

Subadult

The species takes several years to reach adult-type plumage with dark uniform hood and distinct black patterning. Before that, the hood is indistinct and almost lacking in some. Also, it takes at least two years to replace all 1st generation primaries. The 2nd generation secondaries are somewhat intermediate between adult and 1st generation. Second-year birds show immature-type body plumage and remiges, with some inner primaries moulted. Third-year birds show mostly immature-type body plumage with all or almost all primaries moulted, and a second wave of primary moult on the inner primaries. After that, younger birds may still show an intermediate aspect on the body plumage or some remiges, but exact ageing is no longer possible.

Distribution

Sedentary on the Indian peninsula, along the base of the Himalayas, in SE Asia and S China. However, seen regularly on migration on the Thai-Malay peninsula, especially first-year birds.

Geographical variation

The northern nominate from N India and elsewhere in the Himalayas is the largest subspecies. It has the proportionally smallest head, with the brown breast area thinly barred, and the lower breast to flanks and belly variably and irregularly spotted, with the spots being partly pale grey, partly black. The head may be almost black and in general there is little contrast between cheeks and crown, but some have mid-grey cheeks with a moderate contrast. Melanotis of Peninsular India is clearly smaller, with the breast lacking distinct patterning. The lower underparts are patterned much as in the nominate. The head is paler than in the nominate, but the cap is still darkish, creating contrast to the greyish cheeks and chin. Burmanicus of South-East Asia is between the two aforementioned Indian subspecies in size, paler and quite barred and spotted compared to the nominate. The cheeks are paler and browner. The breast shows some light barring, much less and lighter than in the nominate. Ricketti of N Vietnam and S China is larger than burmanicus, but still smaller than the nominate, it is slightly paler, but very similar to burmanicus. The patterning of the underparts is quite similar, but on average the upper breast may be slightly more barred. Malayensis of Thai-Malay peninsula is the smallest and darkest of the continental subspecies. The upper breast is almost unpatterned brown, and the white spotting and barring on the lower underparts is large, regular and distinct. The overall impression of the underparts is of two clearly separated differently patterned areas. The cheeks are often quite greyish. The head looks proportionally large and protruding, while the body seems slim. Compared to the neighbouring subspecies burmanicus, it has less barring on breast and more distinct spotting on the lower underparts.

Life cycle

Breeding time varies geographically, but as a rule, the young fledge in spring and early summer - the species can be classified as a winter and spring breeder. Wing-feathers are usually moulted from April to October, more rarely some moult during the winter.

General

Rounded, quite broad wings and a tail of mid-length. Size and shape reminiscent of Greater Spotted Eagle. Adults show very distinct markings on the remiges which are visible from afar and make it normally easy to identify. First-year birds can be confused with some species of Hawk Eagle Nisaetus or Oriental Honey-buzzard. A very vocal species, with the call often heard from birds flying at great heights. Locally quite common and often seen flying over wooded areas with straight and somewhat stiff wings and perching in trees, when looking quite heavy.

Adult

A bare yellow area between the bill and eye joins the yellow cere. Warm yellow irises. Puffy crest and blackish crown. Otherwise quite brownish underparts, with darker lower head and brownish underwing-coverts. A broad, pale grey sub-terminal band traverses the primaries and secondaries. The fingers as well as the trailing edge of the wing are sharply-defined black and contrast to the pale sub-terminal band. On the inner side of the latter there is a narrower dark bar. The uppersides of the wings have a similar, but much less contrasting pattern. The tail pattern is similar.

First-year

Similar yellowish area between the bill and eyes to adult, and also a prominent crest as in adults, but the eyes are duller and more greenish. There are two morphs, as well as intermediates. One morph with a brown body plumage, superficially similar to adult plumage, while the other is very different, being largely whitish. In these pale birds the underparts from chin to undertail-coverts are mostly pale buffish, although variably dark-streaked, but can sometimes lack streaking altoghether. Brown birds are darkish brown and variably barred whitish. Brown morph individuals differ from adults by having whitish fringing on crown and neck. (Adults have some white feather tips on the neck and upperwing-coverts, which later wear off, but they are narrower. Adults also show white spots on the lesser and median coverts). The best ageing character is the barring on the remiges and rectrices. In juveniles, the bars are narrower than in adults and therefore more similar to those in other raptor species (e.g. Hawk Eagles and Honey-buzzards), with the terminal band also less well defined. Compared to other species of similar size, the yellow area between eyes and bill is often a good distinction. The banding on the wing-feathers is much more prominent than in Short-toed Snake Eagle.

Subadult

The 2nd generation flight feathers are already adult-like, and very different looking to the 1st generation feathers, so ageing subadults is relatively straightforward. 2nd generation body plumage is as in adult. If the bird shows some adult flight feathers of the same age while the rest are juvenile feathers, the bird is in its second year. After the first moult, about half of the primaries show adult type pattern and somewhat less than half of the secondaries show a similar pattern contrasting to the worn juvenile feathers. Third-year birds show adult remiges of two different generations and some juvenile feathers. Typically, after the second moult, the innermost primaries are fresh, while the next ones are slightly worn adult type primaries, the following very fresh adult primaries and the outermost one or two are of juvenile type. There may be no juvenile primaries left, but the age of the bird should still be possible to judge from this moult pattern (fresh-worn-fresh). Most of the secondaries are adult-type at this age, but a few are juvenile.