Identification of pittas in the 'brachyura' complex in Asia: 2
Indian Pitta.
Unlikely to be confused with any other pitta in its range. However, as noted, Mangrove and Blue-winged Pittas both occur in areas where vagrant Indian Pittas could potentially occur. These two species are overall larger and darker, with much more extensive violet-blue, rather than azure-blue, wing patches, violet-blue rumps and broad bold buffy supercilia. They also have considerably more white in the wing and a more chestnut-coloured superciliary band. Both lack the small whitish patch below the eye and the white in the supercilum of Indian Pitta. Immature Mangrove and Blue-winged Pittas also have more extensive blue in the wing and are a richer, orange-buff, below, when compared to similar-aged immature Indian Pittas. It should also be noted that immature Hooded Pittas, Pitta sordida, which may be found in the same areas as breeding Indian Pittas, have black heads with chestnut crown to nape, and a prominent white bar across the wing coverts.
Fairy Pitta.
As noted previously, this species may be found within the potential range of Blue-winged Pitta during migration. Fairy Pitta is paler below than Blue-winged Pitta, has an azure-blue rather than violet-blue wing patch and rump and a more contrasting head pattern. In flight, there is considerably less white in the wing of Fairy than Blue-winged.
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Blue-winged Pitta (Colin Poole) |
Blue-winged Pitta and Mangrove Pitta.
Mangrove Pitta is slightly more robust and larger-billed than Blue-winged (bill >38 mm in length, compared with <32.5 mm), although this may be of little value to a first-time observer obtaining a brief view. Head patterns of these two species, however, also differ, with Mangrove Pitta having distinctly less contrast between the lateral coronal bands (darker than those of Blue-winged) and the more uniform, darker brown crown. Blue-winged Pitta has conspicuous buffy or buffy-brown lateral coronal bands that contrast strongly with the rest of the crown. It also has more black in the top of the crown than Mangrove. If views are exceptionally good, the black chin of Blue-winged Pitta is diagnostic (white in Mangrove). Immature Mangrove Pitta is very similar to immature Blue-winged Pitta, but, like the adult, has a notably larger bill, white chin and the entire crown is brown with variable rufous tones (depending on age) and dark edges to the feathers, giving a scaly appearance.
Voice
Calls of the four species in this group are all distinctive, and can be used to separate potentially sympatric species.
Indian Pitta.
Quite different from the other species, being a clear short double whistle (of monosyllabic notes) 'wheeet-tieu' or 'wieet-pyou' or occasionally, a triple note 'hh-wit-wiyu'. Calling at dawn and dusk also occurs on the wintering grounds, and the Tamil name translates as the 'six-o'clock bird'. In Sri Lanka, Drongos, Dicrurus sp, and Golden-fronted Leafbird, Chloropsis aurifrons, may imitate the call of Indian Pitta, and it is possible that such species may also imitate the calls of other pittas in other parts of their range.
Fairy Pitta.
A clear double whistle, similar to that of Blue-winged Pitta, but it is notably longer and slower and comprises two disyllabic notes: 'kwah-he kwa-wu'.
Blue-winged Pitta.
A loud, clear, fluty double-whistle 'taelaew-taelaew' or 'taewu-taewu' with a distinctive disyllabic quality to both parts ('tae-laew') of the call. The entire call lasts less than a second. A second call, given in alarm, is a harsh, skyeew. Calling is rather seasonal, occurring mostly during the breeding season. During the non-breeding season, they are usually silent except at dawn and dusk, when they may occasionally call, sometimes from their roosts.
Mangrove Pitta.
Also loud and fluty, lasting less than a second. The notes, best described as 'hhwa-hwa' are however more even, with no suggestion of the disyllabic quality of Blue-winged Pitta. The first note rises, but the second is fairly even. At a distance, the call may sound more like the 'tae-laew' of Blue-winged Pitta but, unlike the latter, is not given in couplets, so each, 'tae-laew' phrase is separated from the next by a distinctive pause that may last 3-4 seconds. The call is usually made from the canopy or tree-tops, but, unexpectedly, this species has also been heard calling from within its nest.
Conclusion
Although these four species of pitta are often easy to observe on their breeding grounds, particularly when calling, the three species found in South-East Asia during the northern winter are often silent and difficult to see well. Under these circumstances, prior knowledge of the differences to look for is critical, since they tend to disappear without trace once disturbed. It is useful to bear in mind, however, that at least two species in this group, Indian and Blue-winged Pitta, are apparently territorial on their wintering grounds, so that patience may often pay dividends if one waits or revisits the exact area where a, brachyura, complex pitta was glimpsed.
Acknowledgements
Production of the photographs in the original article in OBC Bulletin
23 was sponsored by Natural History Book Services. The Bulletin article
also contains the relevant plate and distribution maps from the new book
'Pittas, Broadbills and Asities' by Frank Lambert and Martin Woodcock,
published by Pica Press.