Lost and poorly known birds: targets for birders in Asia
by S.H.M. Butchart, N.J. Collar, M.J. Crosby and J.A. Tobias from BirdingASIA 3, June 2005.
The rediscovery of Cebu Flowerpecker Dicaeum quadricolor, by Rob Timmins and others in 1992 on the Philippine island of Cebu (Dutson et al. 1993), was an extraordinary event. The bird had not been seen for 86 years, and had been written off as extinct at least 40 years earlier on the presumption that no forest remained on the island (see Collar 1998; also Magsalay et al. 1995). Six years later, Jon Riley and Jim Wardill finally tracked down the long-tailed blue flycatcher they had been searching for on-and-off for four years on the Indonesian island of Sangihe (Riley & Wardill 2001). In doing so, they put Caerulean Paradise-flycatcher Eutrichomyias rowleyi , firmly back on the ornithological map. It had previously been known only from an 1878 type specimen and a belatedly published sight record in 1978, and had been presumed extinct following fruitless searches in 1985–1986 (Whitten et al. 1987).
Similarly, Jerdon's Courser Rhinoptilus bitorquatus was rediscovered in 1986 in Andhra Pradesh, India, following a coordinated campaign led by the Bombay Natural History Society, with 86 years - like the Cebu Flowerpecker - without a record (Bhushan 1986).
Most recently, in February 2005, Ben King (in litt. 2005) and Julian Donahue rediscovered Rusty-throated Wren Babbler Spelaeornis badeigularis, about 50 km from where the type specimen was collected in 1947 (in the Mishmi Hills of eastern Arunachal Pradesh, India), the only previous record of this species. There are in fact a remarkable number of Asian species that were collected in the nineteenth or early twentieth centuries, and then not recorded for many decades before being rediscovered, or at least re-seen, as modern birdwatching took hold in the region. Examples include: Forest Owlet Athene blewitti (last collected 1884, rediscovered 1997); Damar Flycatcher Ficedula henrici (last collected 1898, next seen again 2001); White-tipped Monarch Monarcha everetti (last collected 1927, next seen again 1993); Black-chinned Monarch M. boanensis (collected 1918, next seen again 1991); Sangihe Shrike-thrush Colluricincla sanghirensis (collected 1878, next seen again 1985); White-browed Nuthatch Sitta victoriae (last recorded 1938, next seen again 1995); Sangihe White-eye Zosterops nehrkorni (collected 1886, next seen again 1996); and Rufous-throated White-eye Madanga ruficollis (collected 1922, next seen again 1995) (BirdLife International 2001, Trainor 2002). In most of these cases the "rediscovery" was mainly just a matter of re-visiting a remote island, but sometimes - as in the cases of Jerdon's Courser and Forest Owlet - the event is only the result of considerable initiative and endeavour.
Rediscovering one of Asia's "lost" species must be in many birders' dreams. Fourteen such birds ripe for rediscovery, some of which remain unseen for over 150 years, are highlighted below. We outline in each case the historical range, details of the last sighting, and priorities for future searches. Birders tend to visit the same popular birding sites, but we strongly encourage people to venture into less known territory in order to track down some of these exciting and enigmatic birds. Such searches are prerequisites for their conservation.
In addition, there are a number of species so poorly known we cannot even classify their conservation status. Such species are placed in the Data Deficient category on the IUCN Red List (IUCN 2001). This applies in cases where there is insufficient information to make a direct, or indirect, assessment of extinction risk. Generally we would not expect these species to prove to be threatened, but more information is needed to permit an adequate assessment. Here we list ten such species from the region for which birders' records could significantly improve our understanding of their ranges, habitats and threats, and hence help clarify their conservation status.
The information below largely derives from the detailed accounts (with point-locality maps) in in Threatened birds of Asia (BirdLife International 2001) and the global summary factsheets in Threatened birds of the world 2004 (BirdLife International 2004; regularly updated online at www.birdlife.org). Readers are directed to these sources for more detailed information and citations to original sources of information. The IUCN Red List categories given below come from the 2005 IUCN Red List, which will be released in autumn 2005, and which is based on the updated factsheets already available at www. birdlife. org.
Crested Shelduck Tadorna cristata Critically Endangered.
This species is known from a small number of records from Primorye in Russia, Hokkaido in Japan (a single nineteenth century record) and South Korea. The last sighting was of a male and two females in May 1964 on islands south of Vladivostok, Russia. A sighting of two males and four females was claimed in North Korea in March 1971, but serious reservations have recently been expressed about the reliability of this record. There have also been several unconfirmed records from north-east China, in Heilongjiang, Jilin, Liaoning and Hebei. Searches are needed in wetlands (including forest rivers) in eastern Russia, North Korea and northeastern China.
Vaurie's Nightjar Caprimulgus centralasicus Data Deficient.
This species is known from a single record in Xinjiang, western China. Several recent surveys of the type-locality and other similar sites in this region have failed to locate it, indicating that it is scarce and presumably localised. The type-specimen was collected in sandy scrubjungle at 1,220 m, and it presumably occurs in desert and semi-desert habitats. However, there has been widespread degradation of these habitats in the Taklimakan Desert through the intensive grazing of goats and camels, extraction of fuelwood, and the conversion of huge areas to irrigated farmland. In 1990, the habitats at the typelocality, Guma, were found to have been greatly altered since the 1920s. Further searches are needed throughout the area. Cleere (1998) suggested that the specimen may actually be an immature of the subspecies of Eurasian Nightjar C. europeaus which breeds in Xinjiang, so further work is also needed to determine its taxonomic status.
Sillem's Mountain Finch Leucosticte sillemi Data Deficient.
This species is known only from two specimens collected in 1929 on a barren plateau at 5, 125 m in southern Xinjiang Autonomous Region, China (in an area under Chinese administration but also claimed by India). Its population is unknown, but it is presumably localised and scarce. One of the birds collected was a juvenile with wings not yet fully grown, and the collector considered that the birds had either bred close to where they were collected or on the nearby peaks in the Kunlun Shan range. It is probably resident at the type-locality, as the adult col- 42 "Lost" and poorly known birds: top targets for birders in Asia lected was in full moult in September. No threats are known and there are unlikely to be any in the remote area from which it is known, but further searches are need to clarify its status and distribution.
Pink-headed Duck Rhodonessa caryophyllacea Critically Endangered (Possibly Extinct).
This striking duck was locally distributed in the wetlands of India, Bangladesh and Myanmar, and occurred rarely in Nepal, with most records from north-east India and adjacent Bangladesh. Recent claims in north-east India were the result of confusion with Red-crested Pochard Netta rufina. It was always considered uncommon or rare and was last seen in the wild in 1949, surviving until around the same time in captivity. It may have been driven extinct by a combination of hunting and habitat loss, but hopes remain that it may be rediscovered in remote wetlands in northern Myanmar. Indeed, in November 2004 there was a possible sighting of a Pink-headed Duck seen in flight in Kachin state, but the views were not good enough to eliminate Spot-billed Duck Anas poecilorhyncha of the subspecies zonorhyncha; further surveys are planned for November 2005 (J. C. Eames in litt. 2004). Other searches are needed in north-east India, particularly in Assam and Bihar.
Nicobar Sparrowhawk Accipter butleri Vulnerable.
This species is endemic to the Nicobar Islands, India, where it is only known with certainty from Car Nicobar and Katchall, with no confirmed records since 1901. Specimens from Great Nicobar and Camorta have proved to refer to Besra A. virgatus, throwing into doubt recent sight records from those islands and from Bompoka, Teressa, Pilu Milu and Little Nicobar. Searches should primarily be focused in forest on Car Nicobar and Katchall, although the species should also be looked for on other islands. Great care is clearly required in distinguishing this species from Besra.
Manipur Bush Quail Perdicula manipurensis Vulnerable.
This species is endemic to northern West Bengal, Assam, Nagaland, Manipur and Meghalaya, north-east India; previously its range apparently extended into Chittagong, Chittagong Hill Tracts and Sylhet districts, Bangladesh. It was historically described as local, but not very rare, although even by the 1930s it was documented as declining in Manipur owing to pressures on its damp grassland habitat. The last confirmed records were of specimens taken in the Manipur valley prior to 1932, although there were unconfirmed reports of five at Nanga in the 1990s (BirdLife International 2001) and of a pair reported by a guide in Dibru-Saikhowa Wildlife Sanctuary, India, in March 1998 (Allen 1998a) - and in the past five years in Deobali Jalah, central Assam (Patar et al. 2004). Searches are needed in grasslands in northeast India and Bangladesh, in particular following up reports by local people at Thoubal and Loktak, Manipur, in November–December 2000 (Kaul et al. 2001). Surveys should be conducted in April-May, when grasslands are burnt, or in October– November, when paddyfields are harvested, as birds are likely to be most visible during these periods (Kaul et al. 2001).
Himalayan Quail Ophrysia superciliosa Critically Endangered.
This species is known only from the western Himalayas in Uttaranchal, northwest India, where about a dozen specimens were collected near Mussooree and Naini Tal up to 1876. Field observations during the midnineteenth century suggest that it may have been relatively common, but within two decades it was certainly rare, potentially indicating a population decline owing to hunting and habitat degradation. The last record was of two at 2, 100 m on the eastern slopes of Sherkadanda, Naini Tal, in December 1876. A number of searches since then have failed to produce any records (including an OBC-funded team led by Rajiv Kalsi in Uttar Pradesh and Himachal Pradesh in 2002–2003), but the species may be difficult to detect (favouring dense grass and being reluctant to fly). There were unconfirmed reports of five sightings in November– December 2003 near Naini Tal ("Y. Arafat" in litt. 2004). Searches are needed in montane grasslands and forest, in particular around Naini Tal and in the Binog Sanctuary - Bhadraj - Jharipani area.
Nicobar Scops Owl Otus alius Data Deficient.
This species is known from two specimens collected in 1966 and 1977 at Campbell Bay on Great Nicobar, the largest of the Nicobar Islands, India. A bird was also netted and photographed by Bandana Aul and S. P. Vijayakumar in March 2003 on Teressa Island (P. C. Rasmussen in litt. 2005). The paratype was found in coastal forest (presumably at sea-level) c. 1 km from the shore. Virtually nothing is known of the species's ecology or possible threats, and further fieldwork is needed.
MAINLAND SOUTH-EAST ASIA
White-eyed River-Martin Eurochelidon sirintarae Critically Endangered.
The extraordinary discovery of this species, followed by its perplexing and almost immediate disappearance, represents one of the most remarkable episodes in Asian ornithology. It was discovered in 1968, at or near Bung Boraphet lake, near the town of Nakhon Sawan in central Thailand. It is known from 12 specimens collected amongst roosts of wintering hirundines (with rumours of many more sold in local markets), one field observation at Bung Boraphet in 1978 (the last confirmed record), and two unconfirmed reports, the last of which was in 1986. The lack of reliable records for over 25 years suggests that it may have undergone a decline, perhaps as a result of habitat degradation and destruction at the (unknown) breeding areas and on wintering grounds, exacerbated by hunting and trapping at roost-sites. Searches are needed in riverine habitats (presumed from its taxonomic affinities) in Thailand, Myanmar, Laos, Cambodia and southern China. White-eyed River-martin has to take the prize as the most desirable Asian bird to rediscover!
Sharpe's Rail Gallirallus sharpei Data Deficient.
This is perhaps the most mysterious Asian species. It is known only from the typespecimen described by Büttikofer in 1893 and no details of its origin are known, but it is speculated that it may have come from the Greater Sundas, Indonesia. Birders throughout the region should be on the look-out for this species, which is similar in size and morphology to Buff-banded Rail G. philippensis, but can be distinguished by its predominantly brownish-black plumage, grey head, chin and throat, white-spotted mantle, scapulars, upperwing-coverts, undertail-coverts and tail, white-barred remiges, and probably red or orange legs and bill (Taylor & van Perlo 1998).
Javanese Lapwing Vanellus macropterus Critically Endangered (Possibly Extinct).
This species is known with certainty only from Java, Indonesia, where it inhabited marshes and river deltas in the west (on the north coast) and the east (on the south coast). A specimen and two eggs collected in the nineteenth century may have derived from Sumatra, and there is an claim that it occurred on Timor (at least three specimens). It was described as local and uncommon, apparently only ever encountered in scattered pairs, and presumably responded badly to extensive habitat degradation and destruction, perhaps compounded by hunting. The last record was of two eggs collected in June 1940 at the Citarum delta near Jakarta. The fact that it was reputedly impossible to overlook suggests very strongly that it is no longer present at any site studied in recent decades by ornithologists, and indeed that it is unlikely to survive at all. However, there were unconfirmed reports from Tanjung Air (near Muara Gembong) in February and April 2004, and good habitat still remains here (Rudyanto in litt. 2004). This site needs surveying urgently, and other coastal wetlands and grasslands should be searched on Java and elsewhere in the Greater Sundas.
Silvery Pigeon Columba argentina Critically Endangered.
This species is a smallisland specialist, known from islands off Sumatra, Indonesia (e.g. Simeulue, Mentawi Islands, Riau and Lingga archipelagos), and off the west coast of Sarawak, Malaysia and Kalimantan, Indonesia (e.g. the Karimata and Natuna Islands, including Burong). There is one confirmed record each from mainland Sumatra and Kalimantan. Formerly locally common, it may have declined through the impacts of introduced mammals, logging and hunting. The last confirmed record was in 1931 at Pulau Gurungan Besar, Karimata Islands, west Borneo. There are recent unconfirmed records from Padang-Sugihan Wildlife Reserve, South Sumatra, in 1984 and 1985 (Nash & Nash 1985), Sembilang River, South Sumatra, where "large numbers" were seen in March 1989 (Verheugt et al. 1993), Padang-Sugihan Wildlife Reserve, South Sumatra, in November 1999 (Iqbal in press), and Pulau Talang Besar, west Borneo, in September 2001 (Wilson 2004). However, none of these records completely eliminates the possibility of confusion with the very similar Pied Imperial Pigeon Ducula bicolor. Searches at these sites to confirm the identity of the birds involved are a high priority, as are surveys of the West Sumatran islands and the Riau and Lingga archipelagos.
Lesser Masked Owl Tyto sororcula Data Deficient.
This owl is known from the island of Buru (and probably Seram) in South Maluku, and Yamdena and Larat in the Tanimbar group, Nusa Tenggara, Indonesia. Most records are of specimens collected in the late nineteenth or early twentieth centuries, and recent observations comprise one photographed individual (probably of this species) on Seram, and one observed on Yamdena. It is probably often overlooked and consequently almost certainly more widespread and numerous than available records suggest. Nevertheless, it occurs in primary and selectively logged lowland evergreen forest, a habitat that is being rapidly cleared from islands within its range by loggers and shifting cultivators. One collector was brought two live birds caught in holes in limestone cliffs on Buru, and this habitat type should be revisited and searched for the species. Information on the current status, distribution and habitat requirements is needed.
Siau Scops Owl Otus siaoensis Critically Endangered.
This species is only known from the holotype collected on the island of Siau, north of Sulawesi, Indonesia, in 1866, having languished in obscurity until resurrected as a full species in 1998 (Lambert & Rasmussen 1998). Just 50 ha of forest remain on Siau, all above 800 m on Gunung Tamata. Since its description, searches for the owl have apparently only been carried out for a few nights in August and October 1998. The bird may conceivably also survive elsewhere on the island in plantations and scrub, as congeners such as Sangihe Scops Owl O. collari tolerate such habitats. Encouragingly, villagers are reportedly familiar with at least two species of owl (Brown Hawk Owl Ninox scutulata also occurs). A WCS/PALS project has been planned for some time (J. C. Wardill in litt. 2003), and searches should concentrate on the montane forest on Siau, followed by other habitats on the island, and smaller islands in the group.
Black-browed Babbler Malacocincla perspicillata Vulnerable.
This species has been unrecorded for longer than any other bird in Asia. It is known by a single specimen dating from between 1843 and 1848. The locality is uncertain, but it is most likely to be around Martapura (or, slightly less likely, Banjarmasin) from South Kalimantan, Indonesia. The taxon was previously considered a race of Horsfield's Babbler M. (Trichastoma) sepiarium or conspecific with the recently discredited Vanderbilt's Babbler M. (Trichastoma) vanderbilti, but it is now considered a valid species (Hoogerwerf 1966, Mees 1995). Searches are required in any remaining areas of lowland forest in South Kalimantan, starting with Pleihari Tanah Laut, where some suitable habitat may remain, even though most has been severely degraded.
Rueck's Blue Flycatcher Cyornis ruckii Critically Endangered.
This enigmatic flycatcher is known from two specimens collected in April 1917 and February 1918, at Tuntungan and Delitua in the lowlands of northern Sumatra, Indonesia. Two further specimens are purportedly from Malaysia, but their provenance has been questioned. The species must have always been very rare or local, given the failure of all but one collector to obtain specimens. No forest remains in the vicinity of the two known collecting localities, so it may have declined severely as a result of habitat destruction. The specimens were collected in "exploited forest", hinting at a tolerance to some degree of habitat degradation. Searches are needed in lowland forest in northern Sumatra (e.g. the Besitang region of Leuser and in Aceh); they should be timed in January–April as the specimens may have represented non-breeding migrants from an unknown breeding population further north.
Blue-wattled Bulbul Pycnonotus nieuwenhuisii Data Deficient.
This obscure taxon is known from north-east Kalimantan (one specimen collected at 600 m in 1900) and Sumatra (one specimen collected in secondary scrub in pasture at 700 m in 1937), Indonesia, and from Brunei, where single birds were seen on five occasions in 1992 in Batu Apoi National Park, in lowland dipterocarp forest at c. 60 m (Williams 2002). It is unusual for bulbuls to be widespread but to occur at such low densities, so this form may represent an extremely rare morph of another species or else a hybrid, although it could be a genuinely rare habitat specialist (Williams 2002). While further taxonomic investigation is clearly needed, birders should look out for this taxon in lowland habitats in Borneo and Sumatra.
Banggai Crow Corvus unicolor Critically Endangered.
This small crow is only known from two specimens taken on an unspecified island in the Banggai archipelago, immediately east of Sulawesi, Indonesia, in 1884–1885. The species may have declined severely, as the last remaining areas of intact rainforest on Banggai island had begun to be selectively logged in 1991 (Indrawan et al. 1993), and it may have been out-competed by Slender-billed Crow C. enca in disturbed lowland habitats. In 1991 and 1996, visits to the island group yielded no unequivocal records. Crows the size of Slender-billed (which occurs on neighbouring Sulawesi and the Sula Islands) were seen at six localities during these visits, with only one sighting of a smaller crow, perhaps this species, in mossy forest at 660 m at the western end of Peleng in November 1991 (Indrawan et al. 1997). Further searches are urgently needed on the Banggai group and more widely in the Sula Islands, starting with mossy forest on Peleng. Mist-netting and recordings of vocalisations would help to confirm identifications.
Luzon or Brown-banded Rail Rallus mirificus Data Deficient.
This species is known from Luzon and Samar in the Philippines, to which it might be endemic, although breeding there has not been confirmed. The majority of records derive from the migration funnel and bird-catching site of Dalton Pass on Luzon, where over 200 were recorded between 1965 and 1970, suggesting that the species may persist in reasonable numbers, and that it is migratory. Although breeding and nonbreeding areas are uncertain, these records infer movements either between the Cagayan valley and Luzon's central plain, or between the Cordillera Central and the Sierra Madre mountains; if the former is true, the records from southern Luzon and Samar may relate to overshooting migrants. In January 2001, an individual was observed in degraded cloud-forest at 2, 240 m on Mount Data, 46 "Lost" and poorly known birds: top targets for birders in Asia Luzon. The bird was heard to call (a frog-like accelerating series of clicking notes), and the same call was heard in cloud-forest at 1, 100 m on Mayon Volcano in southern Luzon (Dinets 2001). Although it has been speculated that it has strict habitat requirements, if these are similar to its congener (and possibly conspecific) Lewin's Rail L. pectoralis (of Australasia and eastern Indonesia), it may prove to be rather cosmopolitan in its preferences, as implied by the few documented details: cloud-forest, near pine forest, and in a small undisturbed riverside swamp, from 550–2,250 m. Surveys to improve our knowledge of this bird, in particular its distribution and habitat requirements, are needed.
Sulu Bleeding-heart Gallicolumba menagei Critically Endangered.
This species is endemic to the Sulu archipelago in the Philippines. It is known by just two specimens taken on Tawi-tawi in 1891, when it was described as extremely rare. It is likely to have declined since, owing to extensive logging and habitat destruction, compounded by hunting and trapping. The only evidence of its continued existence derives from unconfirmed local reports in 1995 from Tawi-tawi and the nearby islands of Siasi, Tandubatu, Dundangan, Baliungan and Simunul. These claim that the species was quite abundant before the 1970s, but had declined dramatically and is now only rarely seen. Despite apparently being well-forested, Tandubatu, Dundangan and Baliungan have a total area of 17 km2, and are thought unlikely to support viable populations. Searches carried out on Tawi-tawi in 1995–1999 were unsuccessful (Allen 1998b,1999), but further fieldwork is needed, in particular in the central massif (where it could have been missed) and in the north-east around Languyan, which has yet to be searched (D. Allen in litt. 2005).
Negros Fruit Dove Ptilinopus arcanus Critically Endangered.
This species is endemic to the Philippines, where it is known only by a single female specimen collected on Mount Canlaon on the island of Negros in 1953. No subsequent fieldworkers on the island have encountered the species, and it may have declined owing to a combination of hunting and extensive habitat destruction (the type-specimen was taken at 1,090–1,120 m, but this may have been at the upper limit of the species). There was an unconfirmed report in 2002 by a local guide at Canaway Forest, inland from Siaton in southern Negros (R. Hutchinson, A. Adcock and S. Woods in litt. 2003). Further searches on Negros, concentrating initially on Mount Canlaon, are needed. In addition, the recent discovery on Panay of threatened species which were previously thought to be restricted to Negros (e.g. Negros Bleeding-heart Gallicolumba keayi and White-throated Jungle Flycatcher Rhinomyias albigularis), suggests that searches on Panay would also be very worthwhile, especially in the lowest-lying dipterocarp forest.
Worcester's or Luzon Buttonquail Turnix worcesteri Data Deficient.
This species is known from just six localities on the island of Luzon in the Philippines. Virtually all records have derived from birdcatchers and are assumed to be intra-island migrants. The limited available evidence suggests that it breeds somewhere in northern Luzon in April–June and that at least some birds disperse southwards in the period July–March. Thus its true range and habitat remain obscure. It appears to be rare, and may be confined to grasslands in the highlands of the Cordillera Central, although records are from 150–1, 250 m, and the possibility that it frequents forested (non-grassland) habitats cannot be discounted. However, buttonquails are a notoriously cryptic and unobtrusive family of birds, and the species could conceivably occur in reasonable numbers somewhere.
Whitehead's Swiftlet Collocalia whiteheadi Data Deficient.
This species is endemic to the Philippines, where it is known from only four mountains, one on Luzon (nominate whiteheadi) and three on Mindanao (race origenis). On Luzon, it was collected on Mt Data in 1895, but has not been recorded there subsequently. On Mindanao, it is known from Mt Apo in 1904 and Mts Kitanglad and Matutum in the 1990s, with specimens taken recently at an unnamed locality in South Cotabato (the same province as Mt Matutum). Its numbers are entirely unknown, partly due to its apparent preference for relatively inaccessible areas and partly due to identification difficulties, even with birds in the hand. Observers should look for the pale-frosted lores, largeheaded appearance and deeply forked tail (Chantler 2000).
Miniature Tit Babbler Micromacronus leytensis Data Deficient.
This species is endemic to the Philippines, where it is known from c. 10 widely spread localities on the islands of Mindanao, Samar, Leyte and possibly Biliran. It appears to be a rare inhabitant of forest and forest edge, from 500 to 1, 670 m (generally above 1,000 m). However, it is tiny - one of the world's smallest passerines - and unobtrusive, and it may prove more common and widespread than current evi- dence suggests, particularly once its behaviour and habitat requirements are better understood, and its vocalisations have been recorded. In addition, parts of Mindanao have insurgency problems, prohibiting surveys, and little recent fieldwork has been carried across much of its range, particularly on Samar and Leyte. Surveys in safe areas (birders can check with the Haribon Foundation for advice on these) are needed here and throughout the range to clarify its status, ecological requirements and possible threats.
We hope that this article will stimulate birders to seek out these species, and that such searches will contribute to the conservation of some of the region's most enigmatic birds. Readers should note that various sources of funding are available to support these activities, e.g. OBC's Conservation Fund, the Royal Society for the Protection of Birds and British Birdwatching Fair research fund for threatened species (contact firstname.lastname@example.org), the British Ornithologists' Union's ornithological research grants (see www.bou.org.uk), the Club 300 Foundation for Bird Protection (email email@example.com), and the BP Conservation Programme (see conservation.bp.com) to name the most obvious.
BirdLife International is responsible for collating information and assessing the status of all the world's birds for the IUCN Red List. We would be pleased to hear of the results of any searches for these or any other threatened species (please email the senior author at the address below). Negative information is also useful, but we are certain that at least some of these species will be successfully rediscovered in the next few years. We eagerly await such news.
We thank the thousands of birdwatchers and ornithologists who contributed information to Threatened birds of Asia and Threatened birds of the world 2004 and who are acknowledged fully in those publications. Thanks also to Des Allen, Jonathan Eames, Pam Rasmussen, Rudyanto and Jim Wardill for responding to queries and providing useful information.
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