Little Known Asian Bird: The Guaiaberoby Thomas Arndt from BirdingASIA 4, December 2005. The Guaiabero Bolbopsittacus lunulatus, one of the world’s least known parrots, is confined to the Philippine islands of Luzon, Leyte, Samar, Mindanao and Panaon. Mainly green and only 15 cm in size, the males have blue lores, cheeks, orbital region and chin, and over the upper back there is a thin pale blue band. Chest, belly and undertail-coverts are yellow-green, as are the lower upperparts and uppertail-coverts. The bill is bluishgrey, blackish towards the tip. Females differ from males by having the blue limited to a small area around the lower bill, and having a small hindcollar of black feathers with a wide yellowish seam. Four subspecies have been described. The nominate form occurs on Luzon, intermedius on Samar and Leyte (this on the whole is darkerplumaged, with stronger blue and, in the female, rather broader hind-collar), and mindanensis on Mindanao and Panaon (in which the male’s blue is restricted to the area around the lower bill and eyes). Placement of the population on Samar in its own subspecies callainipictus is increasingly discounted, since its coloration lies within the range of variation of intermedius. Geographically, too, this separation makes little sense, since Samar and Leyte are less than 3 km apart and too small for us to expect them to possess their own subspecies. The closest relatives of the Guaiabero are certainly the Australasian Psittaculirostris and Cyclopsitta, with which Bolbopsittacus shares a compact body shape, short tail, robust bill and probably also feeding habits.
The Guaiabero has only been kept in captivity a very few times, and it appears to have been imported into Europe only once. Robiller (1997) reported that a Dr Burkard of Switzerland received a few birds in 1965, but that they did not breed. Two individuals came more or less together to San Diego Zoo, but do not seem to have survived very long. The only information about keeping and breeding them is from Janeczek (1994), based on experience gained at the establishment of the Philippine aviculturist Antonio de Dios. Janeczek reported that the birds were extremely delicate. They responded very negatively to being kept in an aviary, and were highly prone to stress. There were multiple deaths, even though care was very intensive and the birds were regularly attended by vets. The animals were clearly sensitive to protozoan infections and they improved only after being put into wire cages and once hygienic conditions had been optimised. Breeding did not occur for five years. The first success was in 1993, with three young hatching after 22 days of incubation, but two of them died at 14 and 16 days respectively, while the third young, removed from the nest for hand-rearing, lived for only 61 days. All four eggs of the second clutch hatched between 24 and 29 May 1993. The chicks were pulled for precautionary reasons after a month, and were independent at 90–110 days. Even so, a stable managed population did not result, and today de Dios appears to have stopped working with these birds. Information from nature is extremely scarce. The species is frequent, lives in open areas, and prefers scrubby clearings and low woodland (Forshaw 1989). In general it occurs up to 1,000 m (Kennedy et al. 2000). Rabor saw it below 600 m on Samar, chiefly in fruiting trees which were either at the edge of forest or in cultivated areas near primary forest, but also in secondary vegetation (Rand & Rabor in Forshaw 1989). Gilliard (in The Guaiabero Forshaw 1989) found it frequently on the Bataan Peninsula on Luzon, where it was mainly found in isolated mango trees. It can also be found in mangrove areas (Collar 1997). It is normally seen singly or in pairs, but sometimes in flocks of up to 20 (Kennedy et al. 2000). On Mt Makiling 50 were seen in vines and the lower branches of a large forest tree, where they secretively climbed about to reach the berries (Amadon & Jewett in Forshaw 1989). Forshaw says the species is easy to see while flying, but is brilliantly camouflaged when settled. Kennedy et al. (2000) call its flight bullet-like, and describe the vocalisations as loud, one- or twosyllabled zeet or zeet-zeet calls, which during feeding are markedly softer. The Grandala is perhaps the most bizarre of the four. The male is glistening purplish-blue with black wings and tail, the female dark brown with white streaking and wing-patch. A rather nomadic denizen of the high Himalayas, breeding up to 5,500 m, its most striking features are its wing-shape - very long wing-tip and rather short secondaries, producing a swallow-like effect - and its gregariousness, wheeling in flocks of tens or hundreds in pursuit of aerial insects, and hopping starling-like across short-grass slopes in search of terrestrial ones. Seebohm (1881) and Ripley (1952) both thought it was closest to Nearctic bluebirds Sialia, but Oates (1890), Oberholser (1919) and Vaurie (1955) demurred. Oberholser put it in its own family, Grandalidae, but the general assumption is that it is a highly modified chat (our photo of a female inclines me to agree). Taxonomists struggle to know where to put the turdine genera Myophonus and Monticola, both of which are characterised by blue plumage, and for the moment I think it makes sense to group Grandala informally with those taxa (but Heraclitus's warning predicts a very different outcome following DNA sampling!). | Guaiabero: 2 |
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