Wildlife of Lao PDR: 1999 Status Report - IUCN

BIRDS
J. W. Duckworth, P. Davidson and R. J. Timmins
INTRODUCTION
Species Included
The following list includes all bird species recorded from
Lao PDR. Provisional records (those modern ones where
observers are confident of the identification but were unable
to clinch it, and those historical ones where subsequent information
suggests a re-examination of any extant specimens
would be desirable) are placed in square brackets. There are
also a few ‘potential’ records. These refer to cases where it is
difficult to distinguish between a closely similar pair of species
(e.g. Riparia riparia and R. diluta; Phylloscopus
sichuanensis and P. chloronotus) and most or all sight records
of birds in these groups are best left unidentified to species.
There are many records of birds observed in Thailand at sites
such as Chiang Saen (Chiang Rai Province) which include
records in the Mekong channel and on islands in the river.
The latter are part of Lao territory. All such records known to
us are incorporated in the following list, but others doubtless
remain to be traced. A few species which have been stated to
occur in Lao PDR in largely authoritative sources, but for
which adequate supporting evidence cannot currently be
traced, are listed in the Appendix to this chapter. Recent field
work has added many new species to the country’s list and
others will undoubtedly be found as work continues; Table 9
lists some potential further additions. Approximately 700
species of bird are known or provisionally recorded from Lao
PDR and another 100 or so are reasonably likely to occur.
Although birds are by far the best surveyed class of animals
in Lao PDR, a more precise total would be of limited use.
The pace at which species new to the country are being found
would render any ‘accurate’ figure obsolete within months
of publication.
Taxonomy and Nomenclature
Sequence, species limits and scientific and English
nomenclature follow An annotated checklist to the birds of
the Oriental region (Inskipp et al. 1996). Differences in species
limits and nomenclature from the two field guides most
frequently used in Lao PDR (King et al. 1975, Lekagul and
Round 1991) and from The distribution and taxonomy of birds
of the world (Sibley and Monroe 1990, as amended 1993)
are indicated. The decisions of Inskipp et al. (1996) are retained
uniformly, as the present list is not a taxonomic work.
Names differing only in orthography from those in Inskipp
et al. (1996) are not presented as alternatives. References for
alternative treatments are abbreviated as in Inskipp et al.
(1996): ^K, King et al. (1975); ^Sm, Sibley and Monroe
(1990, as updated 1993); ^Sm 1 , Sibley and Monroe (1990
only); ^Sm 2 , Sibley and Monroe (1993 only); ^T, Lekagul
and Round (1991).
Distribution Within Lao PDR
For each species, one primary source is cited for each of
north, central and south Lao PDR (see main Introduction) in
which it has been recorded. Where one source listed records
for adjacent regions, it is only cited after the last. For example,
‘centre, south (Thewlis et al. 1998)’ implies that Thewlis
et al. (1998) listed the species for both centre and south. No
attempt is made to indicate the first record for the region,
and indeed the focus is on recent (post-1988) information.
Where possible, citation is to records in refereed journals
rather than to those in internal survey reports or other grey
literature. More details are given for significant records not
yet formally published than for those published.
Key distribution references are abbreviated as follows:
(recent) B1 Duckworth (1996a), B2 Thewlis et al. (1996),
B3 Timmins and Vongkhamheng (1996a), B4 Tizard (1996),
B5 Davidson et al. (1997), B6 Tizard et al. (1997), B7 Tobias
(1997), B8 Davidson (1998), B9 Duckworth et al. (1998a),
B10 Evans and Timmins (1998), B11 Round (1998), B12 Showler
et al. (1998a), B13 Showler et al. (1998b), B14 Thewlis et al.
(1998), B15 Evans et al. (in prep. a), B16 Evans (in prep.),
B17 Walston (in prep.), (historical) B18 Bangs and Van Tyne
(1931), B19 Engelbach (1932), B20 Delacour and Greenway
(1940a), B21 David-Beaulieu (1944), B22 David-Beaulieu (1949-
1950).
Seasonality of Occurrence
Seasonality of occurrence is based on the compilers’ and
other reviewers’ experience. No comprehensive analysis of
seasonality of Lao records has previously been attempted for
most species. Some species are covered nationally in Thewlis
et al. (1996), Duckworth (1996a) and Duckworth et al.
(1998a), and locally in various sources, notably Engelbach
(1932), David-Beaulieu (1944) and Cunningham (1998).
Objective categorisation of the seasonal status of all species
based solely on Lao records is difficult. Many species
are still known by few records. Recent bird survey work has
been concentrated in the months of December to May with
very little during July to October. Few areas have had multiple
visits spread across seasons. Therefore, seasonal categorisations
have incorporated understanding of species’ seasonal
status from neighbouring countries (particularly Thailand;
Lekagul and Round 1991). It is possible that some assessments
will turn out to be misleading. The alternative
would have been the cumbersome insertion of ‘presumed’
before the seasonal status assessment of most species. This
has only been used for species where although we believe
the assessment given to be correct, a larger-than-usual doubt
remains. The selection of species where ‘presumed’ is used
is necessarily somewhat subjective. Ongoing analysis of
recent and historical records will doubtless allow resolution of
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