Crested honey buzzard

Crested honey buzzards migrate for breeding to Siberia and Japan during the summer. They then spend the winter in Southeast Asia and the Indian subcontinent. They are also a year-round resident in these latter areas. They prefer well-forested areas with open spaces and are found from sea level up to 1,800 m (5,900 ft).

The species has several adaptations for its specialist diet. These include an elongated head for foraging on underground nests and a groove in the tongue for extracting wasp grubs from their comb cells. A mass of short, dense feathers on the head and neck protect against stinging attacks by social wasps. Juveniles may have adopted Batesian mimicry to deter predators.

About 57–60 cm (22–24 in) in size, the crested honey buzzard is a fairly large raptor. The head lacks a strong superciliary ridge, giving it a facial appearance very unlike a raptor. It appears long-necked with a small head resembling that of a pigeon. It has a long tail and a short head crest. It is brown above, but not as dark as the European honey buzzard, and paler below. A dark throat stripe is present. Unusually for a large bird of prey, the sexes can be distinguished. The male has a blue-grey head with brown iris, while the female's head is brown and the iris is yellow. She is slightly larger and darker than the male. The male has two black bands in the tail and three black under wing bands, while the female has three black tail bands and four narrower black under wing bands. The juvenile has extensive black primary tips with narrower underwing bands. It has a yellow cere at the base of the bill, and a dark iris. The colouration and the tail pattern of the species are highly variable.

In flight, it is likely to be mistaken at a distance for the short-toed snake-eagle. However, it can be distinguished by its slimmer head and longer neck. It is usually seen soaring singly or in pairs, or perched on a tree top. It is quiet even while nesting, sometimes uttering a single high-pitched screaming whistle. In flight it has deep elastic beats and high upstrokes. It glides and soars on flat or slightly arched wings at right angles to the body. The long broad wings are well rounded at six-fingered tips. The tail is broad, of medium length with a rounded tip. The tail is shorter than the breadth of the wing bases. The wing span is 2.4 times total length in the Palearctic (Eurasian) subspecies, but 2.0–2.2 in the Indo-Malayan subspecies.

The similarity in plumage between juvenile crested honey buzzards and the Nisaetus hawk-eagles may have arisen as a partial protection against predation by larger raptors. The eagles have stronger bills and talons, and are likely to be less vulnerable than the Pernis species. Similar mimicry is shown by the juvenile of the European honey buzzard, which resembles the common buzzard. Although the Eurasian Goshawk is capable of killing both species, it is likely to be more cautious about attacking the better protected Buteo species. These are examples of Batesian mimicry, named after the English naturalist and explorer H.W. Bates who first reported such mimicry in the context of Lepidoptera (moths and butterflies) in 1861.