White-eye Zosterops everetti in KhaoYai, north-east Thailand
By Andrew J. Pierce and Philip D. Round
This article was originally published in Forktail 22 (2006) the journal
of the Oriental
Bird Club (OBC) and was kindly submitted by Philip
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Two white-eyes caught and banded at Mo-singto, Khao
Yai National Park (14°26'N, 101°22'E) on 14
July 2004 at 728 m were identified as Everett’s White-eye
Zosterops everetti. This provides the first confirmed evidence
of the presence of this species in north-east Thailand, and is a
significant extension of the species’s known range, which
was previously considered to extend from the Philippines and the
Greater Sundas, northwards through the Thai-Malaya Peninsula and
south-east Thailand to c.13°N (King et al. 1975, Lekagul and
Round 1991, Robson 2000).
The two birds
were caught between 14h30 and 15h45 in a mist-net placed at the
side of a stream. They were ringed and colour-ringed, and their
biometrics were recorded (Table 1). Both birds were photographed
using a digital camera (Plates 1–2). The salient features
of both individuals were the extent of the yellow on the underparts,
and the lack of yellow on the forecrown. The entire upperparts from
the crown to the uppertail-coverts were uniformly cold olive-green.
In particular, the crown, forehead (extending to the base of the
bill) and the earcoverts were uniform olive-green. There was a sharp
demarcation between the olive-green ear-coverts and the yellow throat.
The remiges and rectrices were blackishcentred, with bright, narrow,
yellow-green fringes. A broad white spectacle was interrupted by
a blackish loral line. The undertail-coverts, hind flanks and thighs
were all yellow, and the yellow extended as an evenly broad, unbroken
median stripe onto the belly and lower breast. The upper breast
was whitish-grey, so that the yellow midline was cut off short of
the throat. The flanks were whitishgrey. The iris was reddish-brown;
the legs were blue-grey and the soles of the feet fleshy-horn (see
1: Biometrics of two Everett’s White-eyes Zosterops
everetti ringed in Khao Yai National Park, Thailand, in July
1 : Everett’s White-eye Zosterops everetti,
July 2004, Khao Yai National Park, Thailand. Photograph: A. Pierce.
Plate 2 : Everett’s White-eye Zosterops
everetti, July 2004, Khao Yai National Park, Thailand. Photograph:
none of the standard field guides (e.g., King 1975, Lekagul and
Round 1991, Robson 1999) mentions the extent and broadness of the
yellow median stripe as a diagnostic feature, this feature was shown
by all Everett’s White-eye specimens examined at the Natural
History Museum, Tring, U.K. Specimens of Oriental White-eyes Z.
palpebrosus (other than Z. p. melanurus and some Z.
p. siamensis, both of which may be completely yellow below)
showed, at most, a narrow broken yellow median stripe along the
belly that extended to neither the yellow on the vent nor the throat.
In many Oriental White-eye specimens there was barely any yellow
on the mid-line, and in all specimens the upperparts were more yellowish-green,
with extensive yellow on the forecrown.
Bearing in mind
the difficulty of distinguishing the upperparts colour (colder green
in Everett’s, more yellowgreen in Oriental White-eye) or the
precise shade of greyish-white on the flanks, the extent of yellow
on the belly is possibly the best field character for distinguishing
So, how many
species of white-eye are resident in Khao Yai and the Dong Phaya
Yen Forest Complex of northeast Thailand, and do Oriental and Everett’s White-eyes occur there
together? In fact, Deignan (1963) did not list Oriental White-eye
for anywhere in the north-east, or away from the coast in eastern
Thailand. Although Dickinson (1963), Dickinson and Tubb (1964) and
McClure (1974) all listed Oriental White-eye for Khao Yai, there
were no Zosterops spp. among the small number of bird specimens
collected in Khao Yai during the 1960s (Dickinson and Chaiyaphun
1968). The listing of Oriental White-eye was based on conversation
between E. C. Dickinson and H. G. Deignan, in which the latter supposed
that Oriental White-eye was the most likely white-eye species to
be found in Khao Yai. However, in 1968, Dickinson identified a flock
of 12 white-eyes in Khao Yai as Everett’s White-eye on the
basis of their ‘very dark flanks’, and all white-eyes
he saw subsequently were likewise identified as Everett’s
White-eye (E. C. Dickinson in litt. 2005). White-eyes in
Khao Yai were also independently identified as Everett’s by
S. Tantidapitak (verbally 2005), from comparison of video images
of both Oriental and Everett’s White-eyes in other parts of
their Thai range, especially in the peninsula.
Thailand’s Dong Phaya Yen forest complex supports two other
species that, like Everett’s White-eye, are mainly Sundaic in
distribution: Scaly-crowned Babbler Malacopteron cinereum
and Moustached Hawk Cuckoo Hierococcyx vagans (Lynam et
al. in press, Lekagul and Round 1991). These species, however,
are known elsewhere in Indochina, in south Laos (both), Cambodia and
Annam (M. cinereum only: Robson 2000). Although Everett’s
White-eye has now been confirmed in Khao Yai, there are, as yet, no
records from elsewhere in Indochina other than from Khao
Soi Dao, Chanthaburi province, south-east Thailand. This
strongly suggests that further surveys may reveal as yet undiscovered,
outlying populations of Everett’s White-eyes in moist evergreen
hill-slope habitats in Indochina, almost certainly in the Cardamom
Mountains of south-west Cambodia, and perhaps elsewhere.
Thus, in addition
to further surveys for Everett’s White-eye, more work is also
required to elucidate the range of Oriental White-eye in north-east
and eastern Thailand and possibly elsewhere in the Indochinese region.
Although Oriental White-eye is apparently widespread in Indochina
(King et al. 1975, Robson 1999, Dickinson 2003), in the
absence of specimens or photographs the presence of this species
in Khao Yai and elsewhere in Dong Phaya Yen must currently be considered
as unconfirmed. If it does occur, it is perhaps more likely to be
found at lower elevations, in disturbed habitats or deciduous woodland
around the park boundaries.
We are grateful to E. C. Dickinson and Sopitcha Tantitadapitak for
making details of their sight records available, and the former for
commenting on this paper. David Wells kindly commented on white-eye
identification. We thank the Department of National Parks, Wildlife
and Plants Conservation for permission to work in Khao Yai, and the
Natural History Museum, Tring, for allowing access to specimens. Work
at Khao Yai was supported by grant BRT 346004 from the Biodiversity,
Research and Training Program, Thailand.
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Howard and Moore complete checklist of the birds of the world.
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field guide to the birds of South-East Asia. London: Collins.
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guide to the birds of Thailand. Bangkok: Saha Karn Bhaet.
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Round, P. D. and Brockelman, W. Y. (in press) Status of birds
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field guide to the birds of South-East Asia. London: New
Pierce, King Mongkut’s University of Technology Thonburi,
School of Bioresources and Technology, Bangkhunthien, Bangkok 10150,
Thailand. Email: firstname.lastname@example.org
D. Round, Department of Biology, Faculty of Science, Mahidol University,
Rama 6 Road, Bangkok 10400, Thailand. Email: email@example.com