W. W. Thomas's Bird Records from Laos, Principally Vientiane, 1966
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FORKTAIL 19 (2003): 63-84 W. W. Thomas’s bird records from Laos, principally Vientiane, 1966–1968 and 1981–1983 J. W. DUCKWORTH and R. J. TIZARD The only primary information about wild birds in Laos between 1949 and 1988 are the records gathered during recreational birdwatching by William W. Thomas, Jr. Although some were incorporated into other people’s publications, most information was hitherto unpublished. During these 40 years, many bird species declined steeply in Laos, and so all of WWT’s records are presented here. They come from 1966–1968 and 1981–1983, mostly from Vientiane town and immediate environs. They form the earliest documentation of Vientiane’s avifauna. Taken together, and in comparison with recent records, they corroborate the declines inferred to have taken place in and around Vientiane for many of the larger birds of wetlands, rivers and other non-forest habitats, and give some indication of timing. They strengthen the evidence that current numbers of most ardeids and sturnids in Laos are unnaturally low. Loss of forest species from Vientiane town reflects local habitat change and does not imply the species are at risk throughout the country. By contrast, factors driving the declines of non-forest birds in and around Vientiane – intensive human use of their habitats leading to habitat degradation and human disturbance, coupled with very heavy opportunistic, and sometimes directed, persecution – are at work throughout the country in such habitats. Many species of these habitats are at risk of national extinction, or at least effective ecological extinction over much of Laos. The records include the first for Laos of several species, all of which have subsequently been found regularly. They provide the only evidence for Black Kite of race Milvus migrans govinda in Laos, a taxon now almost extinct in South-East Asia. The only records from North Laos are given for a suite of species strongly associated with deciduous dipterocarp forest, but there has been no other recent work in this habitat in the North. INTRODUCTION August 1964 and November 1981–November 1983. These observations have remained unpublished until Until recently, the avifauna of Laos remained poorly now, although some were provided by WWT to other known, reflecting limited historical collecting authors (e.g. King et al. 1975). This paper synthesises expeditions, and the small number of residents (all all WWT’s Laos bird notes, paying particular attention foreign) who documented birds. Reflecting several to records of key species of special conservation decades of civil unrest followed by limited access to significance (e.g. threatened, rare, or localised in foreigners, and a continued lack of Lao birdwatchers, distribution), and to records of distributional no published material is known between David-Beaulieu significance. Moreover, this is the first body of bird (1949–1950) and the arrival of R. E. Salter (of IUCN: records from Vientiane; earlier studies of local Lao the World Conservation Union) under the Lao-Swedish avifaunas all covered provincial areas (Engelbach 1932, Forestry Cooperation Programme (LSFCP) in 1988 David-Beaulieu 1944, 1949–1950). Some observations (Salter 1993). The 1990s witnessed extensive bird survey were made in Vientiane from 1992 to 2000 (Thewlis et across Laos, through the LSFCP and subsequently by al. 1996, 1998, Evans and Timmins 1998, Duckworth the Lao PDR government Department of Forestry in et al. 1998a, 1999, 2002, Poulsen in prep.; P. Davidson, collaboration with international conservation NGOs T. D. Evans, W. G. Robichaud, R. J. Timmins, RJT and (Duckworth et al. 1999). During the four decades JWD own data), but these were sporadic and not without records, major changes took place in Lao sufficient to characterise the capital’s avifauna. avifauna. Most notable was the precipitous decline Systematic order and nomenclature of birds follows across most of Laos of larger birds of open habitats, Inskipp et al. (1996). Except for species headings, particularly Green Peafowl, large waterbirds, vultures, scientific names are given in the text only for species fish eagles, kites and Large-billed Crow. Open-country not in the Appendix. Global threat categorisations are birds even as small as mynas were affected. Effects were taken from BirdLife International (2001). Lao risk particularly severe on river channel nesters, notably terns categorisations (At Risk in Laos, Potentially At Risk in (Thewlis et al. 1998, Duckworth et al. 1999, 2002). In Laos, Little Known in Laos) are taken from Duckworth order for modern conservation initiatives to halt or et al. (1999), mindful of additional discussion of open- reverse these declines, understanding of their causes, country birds in Duckworth et al. (2002). The country timings and other characteristics needs to be enhanced. is split into three recording regions, North, Centre and The only information on Lao birds from the period South, following King et al. (1975) as clarified by 1950–1987 appears to be that of William W. Thomas, Jr Duckworth et al. (1999). Place names are based on the (hereafter WWT), who worked at the Embassy of the 1986 series of 1:100,000 maps produced by the RDP United States of America for two spells: August 1962– Lao Service Geographique d’Etat following the minor forktl-0801.pmd 63 8/1/2003, 10:55 AM 64 J. W. DUCKWORTH and R. J. TIZARD Forktail 19 (2003) nomenclature modifications of Thewlis et al. (1998). there were few cars and little noise. Observations were Protected area names follow Thewlis et al. (1998). Most made in a variety of agricultural and village areas, sites, including all those not in Thewlis et al. (1998), are including patches of secondary woodland, and wetlands. shown in Fig. 1. The most notable of the latter was That Louang marsh (then on the edge of Vientiane), which in the 1960s was fairly large and unpolluted. In the early 1980s, it was MAIN SURVEY AREA: VIENTIANE IN smaller and somewhat polluted. By the late 1990s, it THE 1960s–1980s had all but disappeared. In the 1960s, observations were made on several boat trips along on the Mekong river, Throughout WWT’s time, the opportunity to visit not ranging far from Vientiane. These were mostly half- wilderness in Laos was limited, in the 1960s by war- day social events with birding fitted around the schedule. related dangers, and in the 1980s by tight government The Mekong channel around Don Chuan (a large restrictions on movements of westerners. WWT lived sandbar off central Vientiane; referred to as Garden in Vientiane, near the Anousavaly monument in the Island in Duckworth et al. 1998a) was also visited at 1960s, and in Ban Wat Nak in the 1980s. Many this time. Trips were also made to various sites along observations in the 1980s came from his garden and the Mekong river: Xieng Khuang (now the site of the vicinity. Observations could be made regularly only ‘Buddha Park’), Ban Thanaleng (now the site of the within a distance of 6–8 miles of the town centre, Lao-Thai Mekong bridge) and Ban Thadua. These were because of government limits for foreigners’ movements. recorded in WWT’s notes separately from ‘Vientiane’, Some ‘Vientiane’ observations may have been from a suggesting that other areas equivalently far out would little further out, because small roads were rarely marked also have been distinguished from Vientiane. Records to indicate the limits. It was not necessary to go far from designated as from ‘Vientiane’ do not include areas of town to be in the countryside. Even in the 1980s, the extensive or thick forest, and from memory, no land Wat Nak house felt ‘out from town’, and even in town, trip exceeded 15 miles from Vientiane centre. Figure 1: Laos, showing areas visited by W. W. Thomas, and other sites mentioned in the text. forktl-0801.pmd 64 8/1/2003, 10:55 AM Forktail 19 (2003) W. W. Thomas’s bird records from Laos, principally Vientiane 65 METHODS Table 1. W. W. Thomas’s birdwatching trips outside Vientiane. Data sources 1960s In autumn 1999, RJT visited WWT at his home in 19 September 1962: Plain of Jars and Ban Phonsavan America to discuss possibilities for writing up his Lao 8–9 December 1962: Pakxe, Attapu1, Houay Khong2, Champasak1 to bird records. Because of his declining health, we Wat Phu, Paksong, Salavan1 undertook to prepare the information for publication. 23 December 1962: Thanaleng Over the next few months, copies and/or originals of all WWT’s materials related to Lao birds that could be 26–28 December 1962. Louangphabang1 and Pak Ou. traced by WWT and family were sent out to us in Asia. 23 February 1963: Ban Thadua (full list not available) Copies of all material have been deposited with the February 1964: Ban Houayxai (only three species noted) Wildlife Conservation Society Cambodia Programme, as well as being retained in the personal collections of 1980s the authors. There are several basic sources of bird records. WWT’s notebook information from February 22 December 1981: Ban Thanaleng 1963–August 1964 consists of a combined species list 2 or 3 January 1982: Xieng Khuang for Vientiane province (including, by implication, 12 February 1982: Ban Thadua Vientiane municipality) for August 1962–August 1964, 14–15 September 1982: Savannakhet1, but no birds seen, Vangveun3, a list of species in ‘Vientiane’ on 12 April 1964, and Pakxe notes on a few trips outside the capital (Table 1, Fig. 1). For 23 August 1962–February 1963, bird records 19–23 November 1982: Ban Phonsavan. are entered with site, date, and, rarely, counts. Species 29 July–3 August 1983: Louangphabang1 are mostly noted only once, presumably at first sighting. 31 July 1983: Pak Ou Records from the 1980s (2 November 1981–17 10 and 28 October 1983: Phou Hong, Nam Ngum Dam November 1983) are again strongly centred on Vientiane, and are far more detailed than those from 1 There are both towns and provinces of these names; all records are the 1960s.