Surveys in 2018 along the Mekong River, northern Kratie province, Cambodia, indicate a decade of declines in populations of threatened bird species

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CONSERVATION UPDATE
Surveys in 2018 along the Mekong River,
northern Kratie province, Cambodia, indicate
a decade of declines in populations of
threatened bird species
JOHN C. MITTERMEIER, ERIK M. SANDVIG & MERLIJN JOCQUE
Introduction
Cambodia is a significant stronghold for several
populations of threatened bird species in South-
East Asia. Although approaching 20% of Cambodia
is protected, important population s of m any
species of conservation concern remain outside
protected areas (Wright et al. 2012, Goes 2013).
The river ine channels and adjacent terrestria l
habitats of the Mekong River, between the towns
of Kratie and Stu ng Tren g, a re of par ticular
importance for large waterbirds and sandbar-
nesting species, and have been designated part of
an Importa nt Bird Area (IBA) extending from
Kratie nort h to the Lao PDR borde r (BirdLife
International 2019a). Despite their importance,
these habitats have yet to receive a ny formal
protection.
Here we report the result s of a recent bird
survey in this area which was carried out in the
context of a rapid biodiversity assessment of two
pr op os ed protec ted areas for th e Cr iti cal ly
Endangered Indochinese subspecies of the Hog
Deer Axis porcinus annamiticus. The area consists
of a mixture of dry dipterocar p forest, lowland
semi-evergreen forest and wet grasslands, a ll in
varying stages of fragmentation and degradation.
The proximity of the Mekong River also makes the
area of interest for bird conservation because large
waterbirds, such as t he Critically Endangered
White-shouldered Ibis Pseudibis davisoni, may use
them for breeding and foraging.
Timmins (2008) carried out three bird surveys
from 10 November–2 December 2006, 11 March–7
Apri l 2007 and 29 July–23 August 2007, which
foc used pri ma ri ly on riverine and floodplain
habitats in the 130 km stretch of the Mekong River
between Krat ie and St un g Treng. In 2018 we
rev isited this a rea, car rying out bird surveys
around four base camps between 28 April and 17
May. Our efforts focused primarily on terrestrial
habitats in the proposed Hog Deer conservation
areas, but two of our camps were located on river
isla nds and on five days we surveyed r iverine
habitats by boat. Our findings from terrestrial
habitats away from the river supplement the earlier
survey work, whilst our observations in riverine
areas provide a comparison to the prior surveys.
Study area and methods
Cambodia has a distinct dry season from November
to April and a wet season from May to October
which influence the distribution of many species
because of the changes in water levels between
seasons, particularly along the Mekong River and
Tonle Sap floodplains. Our survey would normally
have corresponded wit h the start of t he wet
Figure 1. Locations visited along the central Mekong River,
northern Kratie province, Cambodia, between 28 April and
17 May 2018. Numbers represent the following locations:
(1) Kampi river islands; (2) O Spean camp and wet grassland;
(3) Chroy Banteay Forestry Triage; (4) Koh Khlab island; (5) O Kak
village; (6) Angkor En Community Forest; (7) Khang Lok Krou.
BirdingASIA 32 (2019): 80–89

BirdingASIA 32 (2019) 81
season; however, in May 2018 the rains were late
and, alt hough eveni ng thun de rstorms were
frequent, rainfall was light, with heavy rain on
only five nights, and water levels were generally
low throughout our survey.
The four base camps and the main survey sites
are shown and described in Table 1 and Figure 1.
Examples of the habitats we surveyed are shown
in Plates 1–4.
The sur veys, carried out by JCM and EMS,
aimed to cover as much terra in and a s many
habitats as possible, and began daily shortly after
dawn for 4–5 hours, resuming for a further 3–4
hours in the afternoon and evening, weather
permitting. When possible, nocturnal surveys were
also made. Birds were photographed and sound-
recordings made; archives are available at xeno-
canto (www.xeno-canto.org) and the Macaulay
Library (www.ebird.org). Six mist-nets were set up
on 16 May at the O Chorm stream to supplement
the audio-visua l su r vey. Birds caug ht were
photographed, measured, checked for moult and
breed ing condition, and released. The research
team also included herpetologists, mammalogists
and entomologists, many of whom observed birds
opportunistically during their surveys.
Results
We recorded 219 bird species, includ ing three
End a nge red , t wo Vulne ra ble and 11 Ne ar
Threatened species (Appendix 1). Nine species (18
individuals) were captured during mist-netting,
all of which were also detected during audio-visual
surveys. In addition to accounts of specific species
of interest, we report on breeding activity, migration
and human interference.
Breeding activity
Active nests of seven species were found: River
Tern Sterna aurantia incubating at Khang Lok
Krou, 7 and 10 May; Little Pratincole Glareola lactea
incubating, Kampi river islands, 28 and 30 May;
Blue-tailed Bee-eater Merops philippinus brooding,
Kampi river islands, 29 April; Oriental Magpie Robin
Table 1. Locations surveyed along the Mekong River, northern Kratie province, Cambodia, 28 April to 17 May 2018.
The four base camps were at: (A) Koh Prum Moch Rei, a small river island just north of the Kampi deep pool; (B) O Spean stream,
about 5 km west of the Mekong near Toul Prich village; (C) Koh Khlab, a large river island in the eastern Mekong channels near O Kak
village; and (D) O Chorm stream, about 4.5 km west of the Mekong in the Angkor En Community Forest, near Boeng Char village.
Numbers in brackets in the first column refer to locations marked on Figure 1.
Location Coordinates
Survey
dates Habitat description
Base camp A area
Kampi river islands (1) 12.618°N
106.001°E
28–30
April
Sandy riverine islands; vegetation ranging from tall trees
on the western islands to sandy dunes with tall grasses and
shrubs on the eastern islands.
Base camp B area
O Spean (2)
Chhroy Banteay Forestry
Triage (3)
12.565°N
105.950°E
12.557°N
105.918°E
1–3 May
2–5 May
Abandoned and active ricefields, thickets along a small stream
and patches of degraded dry dipterocarp forest. Of particular
interest is Tam Nub Thea Reas, an area of wet grassland just
south of the camp (12.555°N 105.948°E).
Disturbed dry dipterocarp forest with a canopy of 8–12 m and
evidence of old logging, areas opened for agricultural use and
removal of trees for charcoal.
Base camp C area
Koh Khlab island (4)
O Kak (5)
Khsach Leav village
13.010°N
106.065°E
13.025°N
106.076°E
13.112°N
106.054°E
6–10 May
7 May
6 & 11 May
Semi-evergreen forest on a river island, with some selective
logging, areas opened up for livestock and patches of
degraded understory burnt for hunting.
Relatively undisturbed dry dipterocarp forest on eastern bank
of the Mekong, with a canopy of 10–12 m.
Small riverside village on the east bank that served as our
access point for Koh Khlab island; surrounding habitat included
disturbed dry dipterocarp forest and agricultural fields.
Base camp D area
Angkor En Community Forest (6) 13.020°N
105.926°E
11–17 May Semi-evergreen forest with some evidence of small-scale
selective logging on the west bank of the river; just west of our
camp was a large active logging concession.
Visited from base camp D
Khang Lok Krou (7) 13.335°N
105.937° E
7 & 10 May Sandy riverine island; areas of open sand and dense tall grasses.
A River Tern breeding site actively monitored by WWF and WCS.

82
Copsychus saularis brooding, Kampi river islands,
29 April; White-crested Laughingthrush Garrulax
leucolophus nest-build ing, Koh Khlab Isla nd,
9 May; Stripe-throated Bulbul Pycnonotus finlaysoni
brooding, Angkor En Community Forest, 16 May;
and Oriental Paradise Flycatcher Ter psiphone
affinis incubating, Angkor En Community Forest,
16 May. In addition, on 15 May a female Heart-
spotted Woodpecker Hemicircus canente was near a
nest-hole in the canopy of degraded semi-evergreen
forest, Angkor En Community Forest.
During m ist-netting, seven species showed
extensive brood patches and significant cloacal
protuberances: Banded Kingfisher Lacedo pulchella,
Blue-winged Pitta Pitta moluccensis, Streak-eared
Bulbul Pycnonotus blandfordi, Puff-throated Bulbul
Alophoixus pallidus, White-crested Laughingthrush,
Tickell’s Blue Flycatcher Cyornis tickelliae and
White-rumped Shama Kittacincla malabarica.
Migratory passerines
Our survey coincided with the departure of several
wintering passerine species from Cambodia, and
some of our records sl ightly extend depar tu re
dates published by Goes (2013): Black-naped
Oriole Oriolus chinensis, one on 10 May, previous
latest record 5 May; Red-rumped Swallow Cecropis
daurica, five on 4 May, previous latest record 17
April; Dusky Warbler Phylloscopus fuscatus, 29
April; Oriental Reed Warbler Acrocephalus orientalis,
4 May; Thick-billed Warbler Arundinax aedon, 3
May; Black-browed Reed Warbler Acrocephalus
bistrigiceps, 1 May; Bluethroat Cyanecula svecica, 3
May; Asian Brown Flycatcher Muscicapa dauurica,
30 April, previous latest record 21 April; Red-
throated Flycatcher Ficedula albicilla, 30 April.
Human interference
The most obvious human impact throughout the
area was habitat modification and degradation.
Near O Spean, trees in remaining areas of dry
di pteroc arp fore st were being cut dow n for
charcoal production. On Koh Khlab, large areas
of understory had been burnt (Plate 3) to clear
areas for hunting terrestrial mammals such as
deer; patches of forest on the north of the island
had been cleared for agriculture and the forest had
been selectively logged throughout. Near Angkor
En, a logging company was actively building roads
and extracting timber (Plate 5). Probably the most
obvious direct impact was the collection of birds’
eggs and chicks—on Koh Prum Mocha Rei people
were d igg ing out Blue-tailed Bee-eater nests to
obtain eggs and newly-hatched chicks (Plate 6)
and killing adult birds with slingshots. Chick and
egg collection on this scale is clearly unsustainable
and thus a serious threat, particularly for colonially
nesting species on small riverine islands. However,
in general, birds seemed to be less directly impacted
than other species such as mammals and turtles.
Selected species accounts
Green Peafowl Pavo muticus EN
The Green Peafowl has been widely extirpated
by habitat conversion and hunt ing and is now
designated Endangered (BirdLife Internationa l
2019b). Cambod ia rema ins important for the
species, despite dramatic population declines in
the last 50 years (Goes 2013). Timmins (2008) found
it common in riverine habitats and we recorded
it f requently on Koh Khlab, with at least nine
individuals present here and on the neighbouring
ALL IMAGES TAK EN IN KRATIE PROVINCE, CAMBODIA, BY JOHN C. MITTERMEIER
Plate 1. A small river island north of Kampi deep pool, 29 April 2018.
Surveys in 2018 along the Mekong River, northern Kratie province, Cambodia

BirdingASIA 32 (2019) 83
Plate 2. Dr y dipterocarp forest near O Kak village, 6 May 2018. Plate 3. Tall forest with burned understory on Koh Khlab island,
10 May 2018.
Plate 4. Semi -evergreen forest in Angkor En Community
Forest, 13 May 2018.
Plate 5. Logging in a concession near Angkor En Community
Forest, 15 May 2018.
Plate 6. Har vesting of nests of colony-nesting species, in
this case chick s taken from Blue-tailed Bee-eater Merops
philippinus nests on Koh Prum Mocha Rei island, 29 April 2018.
island. The species was also seen once in the logging
area near Angkor En. Our observations support
previous findings that Green Peafowl is relatively
common here, but very vulnerable to increasing
hunting pressure—cessation of hunting should be
a priority for conservation efforts in the area.
Storks Ciconiidae
Cam bod i a h ol ds i mpo r tan t popu l at i on s of
four s pecies of g lobally threatened stork: t he
Endangered Greater Adjutant Leptoptilos dubius,
Vulnerable Lesser Adjutant L. javanicus and
Asian Woollyneck Ciconia episcopus, and Nea r
Threatened Painted Stork Mycteria leucocephala.
Timmins (2008) observed all these species, finding
Asian Wool ly neck ‘fre que nt to common’ and
rec ord ing Lesser Adjutant on all his surveys,
concluding that there was a sizeable local breeding
population which was a significant part of the
north and east Cambodian population.
Our results give cause for concern: neither
Greater nor Lesser Adjutant were seen, and Asian
Woollyneck only three times—one soaring on 5
May at Chhroy Banteay, two on 11 May north of
Khsach Leav village, and 12 over the Mekong on 11
May near Koh Khlab. Our only other sighting was
of seven Painted Storks on 2 May in the O Spean
wet meadows. Storks are usually conspicuous and,
although the different methodology and times of
year compared with Timmins (2008) could explain
the discrepancies, the absence of Lesser Adjutant
is worr ying: the species breeds colonia lly and
is suscept ible to human disturbance at nesting
sites, causing ver y low breeding success, hence
disturbance around nesting colonies may have
led to a significant decline (BirdLife International
2019c).

84 Surveys in 2018 along the Mekong River, northern Kratie province, Cambodia
White-shouldered Ibis Pseudibis davisoni CR
The global population of this Critically Endangered
species is estimated to be about 1,000 individuals,
with 87–95% in Cambodia (Birdlife International
2019d). Timmins (2008) found the species to be
‘locally common’, with an estimated 78–125 birds
between Kratie and Stung Treng. Similarly, Wright
et al. (2012) estimated that 124 individuals roosted
in t he same section of the river. We found the
species on four occasions—seven flying to roost in
trees on a small river island at Kampi on 30 April;
three flying over Koh Prum Mocha Rei on 1 May;
two feeding in a ricefield east of Angkor En on 14
May; and a guarded nest (Sok et al. 2012) with two
chicks near Khsach Leav village on 6 and 11 May.
Fish Eagles
Ti m min s (2008) reco rd ed bot h Lesser Fis h
Eagle Icthyophaga humilis and Grey-headed Fish
Eagle I. ichthyaetus on the Mekong, t he latter
predominating with around 150 sightings between
Kratie and Stung Treng. We found Grey-headed
Fish Eagle only once, a single bird near Koh Khlab,
and did not see a Lesser Fish Eagle. Even allowing
for the differences in methodology of the surveys
noted previously, this discrepancy is surprising
and worrying. Goes (2013) noted that Grey-headed
Fish Eagle had declined away from Prek Toal,
and BirdLife International (2019e) describe the
species as ‘scarce and declining’ in Cambodia. A
focused survey of this area is needed to assess the
species’s status.
Vultures
The three Cambodian resident vulture species,
Red-headed Vulture Sarcogyps calvus, White-
rumped Vulture Gyps bengalensis and Slender-
billed Vulture G. tenuirostris, are all designated
Critically Endangered. Timmins (2008) obser ved
them all in small numbers: Red-headed Vulture,
five birds, White-rumped Vulture, three birds, and
Slender-billed Vulture, one bird. Despite looking
specifically for vultures, none were seen during our
survey. A dead cow left out near O Kak village in
the first week of May did not attract any vultures,
nor had any visited a feeding station set up the
previous month.
Great Thick-knee Esacus recurvirostris NT
A study in 2010–2012 estimated a Mekong population
of about 100 individuals (Goes 2013). We observed
only small numbers on the Kampi river islands
(Plate 7), up to three on Koh Prum Mocha Rei
between 28 April–1 May, one on Khang Lok Krou,
7 and 10 May, and one on 14 May at Sre Chrey
village on the western Mekong channel. Given
the pressure that we observed on birds nesting in
riverine habitats, we concur with Goes (2013) that
this species is probably threatened in this region.
River Lapwing Vanellus duvaucelii NT
Timmins (2008) found this species common in
the dry season but did not record it in the July –
August 2007 wet season. We found notably fewer
than Timmins (2008), only three near Koh Khlab
and three or four on Khang Lok Krau, 7 and 10
May. The difference may have been because our
survey was near the end of the dry season; neither
Timmins nor our group found this species around
the Kampi river islands.
Spotted Greenshank Tringa guttifer EN
The Endangered Spotted Greenshank winters on
coastal mudflats in South-East Asia and breeds
in eastern Siberia, but its movements between
winteri ng and breed ing g rounds are poorly
understood. We observed a single bird in winter
plumage in company with a Common Greenshank
T. nebularia on a sandbank at Khang Lok Krau on
7 May; its identity was confirmed by S. Mahood
(images available on eBird.org). This observation
provides further evidence that the Mekong may be
a north–south corridor for migratory species and
that the riverine habitats may provide important
stop-over points for migratory shorebirds (Schwilk
& Claassen 2012).
River Tern Sterna aurantia NT
River Tern is designated globally Near Threatened
(BirdLife International 2019f), with South-East
Asia’s population, including Cambodia’s, declining
sharply—Timmins (2008) reported that north-east
Cambodia supported the last breeding population
in the Mekong basin; he estimated that 100 birds
Plate 7. Great Thick-kne e Esacus recurvirostris on Koh Prum
Mocha Rei island, 30 April 2018.

BirdingASIA 32 (2019) 85
were present on the Mekong between Kratie and
Stung Treng but found that many left the area in
the wet season, moving south of Kratie town at this
time. We only observed River Tern at Khang Lok
Krau (Plate 8), where two nests were seen on 7 May,
reduced to one by 10 May due to rat predation in the
intervening period. A wire mesh enclosure around
the nest-site to exclude rats and other terrestrial
predators had been erected by a ‘tern guardian’, a
local man hired to live on the island and monitor
the nests during the breeding season (Plates 9 &
10). Predation is clearly an issue and the enclosure
was not effective; the ongoing effective protection
of nests (Sok et al. 2012) and nesting islands is
vital to the survival of this species in the region.
Plate 9. Nesting River Tern showing the ineffective protec tive fencing, 7 May 2018.
Plate 10. River Tern eggs are especially susceptible to poaching or trampling by humans, 7 May 2018.
Plate 8. Adult River Tern Sterna aurantia on Khang Lok Krau
island, 7 May 2018.

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Great Hornbill Buceros bicornis NT
This species is globally Near Threatened and
under threat in Cambodia, where populations
outside protected a reas are probably fragmented
and badly impacted by hunting and loss of nesting
trees. Timmins (2008) found the species only on
one occasion, two birds near Koh Veng Thom on
19 August 2007, and concluded that it might only
be a seasonal or occasional visitor to the area.
Similarly, we only observed the species once—a
pair in the active logging concession near Angkor
En Community Forest on 14 May.
Woodpeckers Picidae
Over 20 species have been recorded in the country,
but relatively little is known of the precise habitat
prefere nc es of so many ecolo gical ly s imi lar
species. We recorded 13 species of woodpecker,
with their habitats noted as follows: Heart-
spotted Woodpecker, seen once near a nest-hole
in Angkor En (see Breeding Activity); Rufous-
bellied Woodpecker Dendrocopos hyperythrus,
a pa ir in good dr y dipterocarp woodland at O
Kak, 7 May; Grey-capped Woodpecker Picoides
canicapillus, fai rly common at Chhroy Banteay,
up to seven r ecorded daily in the canopy of
degraded dr y dipterocarp forest, and uncommon
at A n gkor En, one to t wo rec or de d on t wo
days, although probably under-detected in the
canopy of semi-evergreen forest; Yellow-crowned
Woodpe cker Leiopicus mahrattensis, a pair in good
dry d ipterocarp forest at O Kak, 7 May; Greater
Yel low nap e Chrysophlegma flavinucha and Lesser
Yel low nap e Picus chlorolophus, both uncommon
in the middle and upper levels of semi-evergreen
forest at Angkor En; Laced Woodpecker P. vi ttatu s,
surprisingly ra re, seen once in scattered trees
near the O Spean grasslands, 3 May; Streak-
throated Woodpecker P. xantho py ga eus , seen
once in good dry dipterocar p forest at O Kak, 7
May; Black-headed Woodpecker P. erythr op yg ius,
fairly common in the mid-story and sub-canopy
of varied habitats, including degraded and good
dr y dipterocar p forest, se mi-evergreen forest
and r iverine forest; Black-naped Woodpecker P.
guerini, uncommon in degraded dry dipterocarp
forest and fairly common in riverine forest and
semi-evergreen forest, where it was seen from
near ground level to the sub-canopy; Common
Flameback Dinopium javanense, fairly common
in open habitat, including degraded a nd good
dipterocarp forest and in widely spaced trees on
small river islands, but uncommon in open semi-
evergreen forest; Greater Flameback Chrysocolaptes
guttacristatus, fairly common in the middle and
upper levels of r iverine forest and upper areas
of semi-everg reen forest; Rufous Woodpecker
Micropternus brachyurus, seen t wice in open
degraded dry dipterocarp forest at Chhroy Banteay,
4 and 5 May. These observations highlight the
importance of dry dipterocarp forest as fou nd
around O Kak village for several of the more
uncommon woodpecker species, such as Rufous-
bellied and Yellow-crowned Woodpeckers. Neither
of the two largest Cambodian woodpecker species,
Great Slaty Mulleripicus pulverulentus a nd W hite-
bellied Dryocopus javensis Woodpeckers, were
seen during our surveys.
Parakeets Psittacidae
Blossom-headed Psittacula roseata, Red-breasted P.
alexandri and Alexandrine P. eupatria Parakeets
are all designated globally Near Threatened. We
found Blossom-headed Para keet to be common
around O Kak village and also saw single birds on
Kampi river islands and Chhroy Banteay Forestry
Triage, while Red-breasted Parakeet was common
at all sites. Alexandrine Parakeet was not recorded
during our survey, thus supporting the statement in
Goes (2013) that it is the most threatened lowland
parakeet in Cambodia.
White-browed Reed Warbler Acrocephalus
tangorum VU
This species is designated Vulnerable, with loss of
preferred wintering habitat in Indochina being one
of the reasons for its decline (BirdLife International
2019g). Cambod ia is an impor tant w inter ing
ground for the species. We observed up to four
Wh ite-browed Reed Wa rbler in the O Spe an
waist-high wet grassland (Plate 11) on 2–3 May—
apparently the first records for Kratie province
(Goes 2013).
Green-backed Flycatcher Ficedula elisae
The species is a rare vagrant in Cambodia, with
three previous autumn records. On 30 April we
observed a single female Green-backed Flycatcher
foraging in the sub-ca nopy of a sma ll forested
island in the Kampi rivers (12.618°N 105.992°E)—
the first spring record and the second record of a
female for Cambodia (Goes 2013).
Red Avadavat Amandava amandava
The Red Avadavat is dependent on wet grasslands
and is of conservation concern in Cambodia, where
this habitat has been converted to agriculture.
Goes (2013) summarised previous records from
Kratie marsh on the Mekong’s east bank. On 2
and 3 May we saw up to 16 Red Avadavat foraging
in the wet grasslands near O Spean, apparently a
new site for this species—a further reason for the
protection of this and ot her small patches of wet
grassland.
Surveys in 2018 along the Mekong River, northern Kratie province, Cambodia

BirdingASIA 32 (2019) 87
Mekong Wagtail Motacilla samveasnae NT
Timmins (2008) found Mekong Wagtail ‘relatively
abundant’ in this area, a stronghold of the species.
Similarly, we encountered up to six daily in the
appropriate habitat around the Kampi river islands
and observed two birds on trips between Koh Khlab
and Khang Lok Krou on 7 May.
Species not recorded
In addition to comments above about spec ies
recorded by Timmins (2008) but not seen during
the 2018 survey, there have been very occasional
records of the Critically Endangered Giant Ibis
Pseudibis gigantea from the dr y forest habitats
in the area (Sok Ko pers. comm.) but there were
no repor ts of this spec ies du ring our survey.
Likewise, the Endangered Masked Finfoot Heliopais
personatus was observed once, in March 2007
(Timmins 2008), but was not seen by our team.
Streaked Weaver Ploceus manyar and the Near
Threatened Asian Golden Weaver P. hypoxanthus,
both under threat in Cambodia, could potentially
occur in habitats found in this region but were not
found in either the 2006–2007 or 2018 surveys—
although Timmins (2008) found both species at a
single location which we did not visit.
Discussion
Our results highlight the apparent decl ine of
several threatened species since the surveys of
Timmins (2008). The very low numbers of Grey-
headed Fish Eagle and the absence of vultures and
Lesser Adjutant are notable and suggest the need
for a more thorough evaluation.
Timmins (2008) hypothesised that the habitats
further from the Mekong would be of relatively
low conservation signific ance for birds, both
because they were similar to those found over large
areas of north and east Cambodia and because
the region is already home to a relatively high
human population, making it unli kely to hold
species that are sensitive to human persecution.
Our result s overal l support this, all the forest
species we encountered are widespread in northern
Cambodia, and species most sensitive to human
disturbance were either absent, e.g. Giant Ibis and
Sarus Crane Antigone antigone, or only present in
low numbers, e.g. Great Hornbill. An exception
was the wet grassland (Plate 12) south of O Spean
(12.555°N 105.948°E), important for the remaining
populations of Hog Deer and where we found the
Vulnerable White-browed Reed Warbler and Red
Avadavat. Habitat loss (Plate 13) is a major driver
of the declines of both species in Cambodia, further
highlighting the importance of protecting patches
of wet grassland, which may also be wintering
habitat for the Critically Endangered Yellow-
breasted Bunting Emberiza aureola. Protecting wet
grassland from conversion to agriculture should be
a top conservation priority in the proposed Preak
Prasab Wildlife Sanctuary.
Our findings also confirm the importance of
conserving good quality dr y dipterocarp forest
for White-shouldered Ibis and other species. We
found that the area around O Kak contained the
highest quality dry dipteroca rp forest that we
encountered during our surveys and it certainly
merits protection (Plate 2).
A 2009 assessment by BirdLife International
concluded that the areas covered by this survey,
part ic ul arly those contiguous with t he river,
are under serious threat, in poor condition, and
that little action has been taken to remedy these
problems (BirdL ife I nternat ional 2019a). Our
observat ions support this assessment. Specific
threats to birds encountered during the survey were:
habitat degradation through the rapid expansion
of selective logging for charcoal production and
hardwood harvesting; habitat destruction and
fragmentation caused by agricultural expansion,
e.g. rubber and cashew plantations; and poaching,
including nest harvesting and hunting of adults
of riveri ne island and colonial-nesting species.
Finally, the proposed da ms on the Mekong, if
approved, wou ld des troy i mportant river ine
habitat and dramatically change the water regimes
downriver (International Rivers 2014).
Cagebird trade
Elsewhere in South-East Asia, t rappi ng for the
cagebird trade has decimated Common Hill Myna
Plate 11. White-browed Reed Warbler Acrocep halus tangorum
in wet grassland, 3 May 2018.

88
Gracula religiosa a nd White-ru mped Sha ma
populations, leading to local extinctions. Although
both species were being kept as pets in Kratie,
trapping pressure is apparently low in this region
as White-rumped Shama was common or fairly
common in all locations with suitable habitat,
including O Spean creek, where it was common
despite the proximity of a fairly large town with
significant levels of human activity. Likewise,
Common Hill Myna was common and conspicuous
in semi-evergreen forest at Angkor En.
Ecotourism potential
The Kam pi r iver islands a re already known
to birdwatchers look in g for Mekong Wagt ail.
Highlighting the fact that White-shouldered Ibis
occurs in the area, and that White-browed Reed
Warbler may be seen in winter on a day trip
from Kratie, would potentially help to expand
bird ecotourism at this site. A visit to the dry
dipterocarp forest near O Kak village provides an
excellent opportunity to look for woodpeckers,
while the Green Peafowl present on Koh Khlab
make this site interesting as well.
Conservation recommendations
We have four recomme nda tio ns for av ian
conse rvation in the area: 1) prote ct a reas of
cr itica lly i mportant wetland habitat—r iverine
areas and wet g rasslands; 2) continue targeted
nest protection for White-shouldered Ibis, River
Tern and other species; 3) a more thorough re-
survey of Timm ins’s 2006–2007 study to reassess
populations of large waterbirds; and 4) prevent
hunting of species such as Green Peafowl and the
trapping of birds for the pet trade.
Surveys in 2018 along the Mekong River, northern Kratie province, Cambodia
Plate 12. Wet grasslands near O Spean creek, 3 May 2018.
Plate 13. Ploughed wet grassland for conversion to agricultural fields near O Spean, 2 M ay 2018.

BirdingASIA 32 (2019) 89
Acknowledgements
We were part of a large field team and benefited
greatly from observat ions by ou r fellow team
members Tim van Berkel, Justin Clause, Sam Puls,
Willem Stock, Mac Stone and Willem-Jan Emsens.
The exped ition was supported and funded by
WWF-Belgium and WWF-Cambodia. We thank
Isabelle Vertriest, Jerome Laycock, Chandet Horm,
Rin Naroeun, Somany Phay, Teak Seng, Vong
Puthkanha and Thibault Leclercq for their support,
and Samnang Keo, Kao Sokhon, Kim Hoeun and
Sok Ko for help in the field. Heng Neathmony of
the Cambodian Ministry of Environment provided
constructive collaboration during our time in the
field. We than k t he commu ne chiefs of Boeng
Char, O Krieng and Chhroy Banteay, the district
governors of Preak Prasab and Sambo and the
Kratie provinc ia l governor for al low in g us to
conduct research in their regions. Finally, we thank
both Frederic Goes and Simon Mahood for their
generous help in providing feedback and ideas on
early versions of this manuscript.
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BirdLife International (2019c) Species factsheet: Leptoptilos javanicus.
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Accessed at http://www.birdlife.org on 05/11/2019.
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Accessed at http://www.birdlife.org on 05/11/2019.
BirdLife Inte rnational (2019f) Species fac tshee t: Sterna aurantia.
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Accessed at http://www.birdlife.org on 05/11/2019.
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and Cuculus (saturatus) optatus. Forktail 23: 12–16.
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62–63.
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Cambodian J. Natural Histor y 2: 111–114.
Sok, K., Claassen, A. H., Wright, H. L. & Ryan, G. E. (2012) Waterbird
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with notes on the recovery and release of white-shouldered ibis
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Treng Towns, northeast Cambodia, 2006-2007. Phnom Penh: WWF
Greater Mekong Program – Cambo dia Countr y Programm e,
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Wright, H. L., Collar, N. J., Lake, I. R ., Norin, N., Vann, R., Ko, S., Sum, P.
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protected areas. Oryx 46(2): 236–239.
John C. MIT TERMEIER
School of Geography and the Environment
University of Oxford, South Parks Road
Oxford OX1 3UJ, UK
Email (corresponding author):
john.mittermeier@gmail.com
Erik M. SANDVIG
Edward Grey Institute of Field Ornithology
Department of Zoology, University of Oxford
Oxford OX1 3SZ, UK
Merlijn JOCQUE
Biodiversity Inventory for Conservation
Walmersumstraat 44, 3880 Glabbeek, Belgium and
Aquatic and Terrestrial Ecology
Royal Belgian Institute of Natural Sciences (RBINS)
Vautierstraat 29, 1000 Brussels, Belgium

90 Surveys in 2018 along the Mekong River, northern Kratie province, Cambodia
Lesser Whistling Duck f f u
Dendrocygna javanica
Indian Spot-billed Duck f f c
Anas poecilorhyncha
Green-legged Partridge u
Arborophila chloropus
Green Peafowl Pavo mu ticus EN f r
Chinese Francolin f f f
Franco linus pintad eanus
Red Junglefowl Gallus gallus f u
Siamese Fireback Lophura diardi r
Asian Openbill Anastomus oscitans u
Asian Woollyneck Ciconia episcopus VU r u u
Painted Stork u
Mycteria leucocephala NT
Little Cormorant Microcarbo niger c c c
Indian Cormorant f
Phalacroco rax fuscicollis
Oriental Darter c c c
Anhinga melanogaster NT
Spot-billed Pelican r
Pelecanus philippensis NT
Yel low B it ter n Ixobr ychus sinensis u r
Cinnamon Bittern r u
Ixobrychus cinnamomeus
Black Bittern Ixobrychus flavicollis u f
Grey Heron Ardea cinerea u c
Purple Heron Ardea purpurea u f
Great Egret Ardea alba f u
Intermediate Egret Ardea intermedia u r
Little Egret Egretta gar zetta u r u
Cattle Egret Bubulcus ibis c c
Chinese Pond Heron Ardeola bacchus r
Javan Pond Heron Ardeola speciosa r
pond heron Ardeola sp. (Note 1) c c
Green-backed Heron Butorides striata c u
Black-crowned Night Heron u u
Nycticorax nycticorax
White-shouldered Ibis f r r
Pseudibis davisoni CR
Osprey Pandio n halia etus u u
Black-winged Kite Elanus caerule us f u
Crested Honey Buzzard u u
Pernis pt ilorhynchus
Black Baza Aviceda leup hotes u u
Crested Serpent Eagle Spilornis cheela u f f
Rufous-winged Buzzard r r u
Butastur liventer
Shikra Accipiter badius u u u
sparrowhawk Accipiter sp. u u u
Brahminy Kite Haliastur indus u
Grey-headed Fish Eagle r
Icthyophaga ichthyaetus NT
White-breasted Waterhen u f r
Amaurornis phoenicurus
Waterco ck Gallicrex cinerea u
Purple Swamphen r
Porphyrio porphyrio in dicus (Note 2)
Great Thick-knee Esacus recurvirostris u r u
Pacific Golden Plover Pluvia lis fulva r
River Lapwing Vanell us d uvau celi i NT f
Red-wattled Lapwing Vane llus ind icus f f f u
Little Ringed Plover Charadrius dubius f u c
Red-necked Stint Calidris ruficollis NT (Note 3) r
snipe Gallinago sp. (Note 4) r
Common Sandpiper Actitis hypoleucos u
Common Greenshank Trin ga n ebu la ri a r
Spotted Greenshank Tri nga g ut ti fer EN r
Barred Buttonquail Tur ni x sus ci ta to r f f f r
Oriental Pratincole Glareola maldivarum f
Little Pratincole Glareola lactea c c
Caspian Tern Hydroprogne caspia u
Whiskered Tern Chlidonias hybrida u
River Tern Ste rna aurantia NT c
Red Turtle Dove Streptopelia tranquebarica f c c
Eastern Spotted Dove Streptopelia chinensis f c c u f
Grey-capped Emerald Dove r f
Chalcophaps indica
Zebra Dove Geopelia striata u f c f
Orange-breasted Green Pigeon r
Tre ro n b ic in ct us
Thick-billed Green Pigeon Trero n cu rv ir ost ra f f
Yellow-footed Green Pigeon u c r
Tre ro n p ho en ico pt er us
Green Imperial Pigeon Ducula aenea f r f u
Greater Coucal Centropus sinensis f f c u f
Lesser Coucal Centropus bengalensis u c c
Green-billed Malkoha Phaenicoph aeus tristis r u u u
Western Koe l Eudynamys scolo paceus u u f u u u
Banded Bay Cuckoo Cacomantis sonnerati i r
Plaintive Cuckoo Cacomantis me rulinus r u u
Square-tailed Drongo Cuckoo u
Surniculus l ugubris
Indian Cuckoo Cuculus m icropter us u
Himalayan Cuckoo Cuculus sat uratus (Note 5) r u
Common Barn Owl Tyt o al ba r
Oriental Bay Owl Phodilus badius r
Collared Scops Owl Otus lettia r u
Species 1 2 3 4 5 6 7
Species 1 2 3 4 5 6 7
Appendix 1
Species observed during surveys along the Mekong River, northern Kratie province, Cambodia, 28 April–17 May 2018.
Key: numbered columns are the following locations: 1) Kampi river islands; 2) O Spean camp and the wet grasslands; 3) Chroy Banteay Forestry
Triage; 4) Koh Khlab island; 5) dry dipterocarp forest around O Kak and Khsach Leav villages; 6) Angkor En Community Forest; 7) Khang Lok Krou.
Relative abundance codes: c = common, > 10 individuals per day; f = fairly common, 4 –10 individuals per day; u = uncommon, 1–3 per day; and
r = rare, < 1 per day.
For globally threatened species, Red List status are shown: NT = Near Threatened, VU = Vulnerable, EN = Endangered, CR = Critically Endangered.

BirdingASIA 32 (2019) 91
Brown Fish Owl Ketupa zeyl onensis u u r
Spotted Owlet Athene brama r
Asian Barred Owlet Glaucidium cuculoides f u
Collared Owlet Glaucidium brodiei r
Horsfield’s Frogmouth r
Batrachostomus javensis
Great Eared Nightjar Lyncornis macrotis r u
Large-tailed Nightjar Caprimulgus macrurus u u u u
Brown-backed Needletail c
Hirundapus giganteus
large swift Hirundapus sp. u u
dark swiftlet Aerodramus sp. (Note 6) c c c f f
Asian Palm Swift Cyps iu ru s ba las ie ns is f c c f r r
Crested Treeswift Hemiprocne coronata c u c r
Common Hoopoe Upupa epops u u f r f
Great Hornbill Buceros bicornis NT r
Oriental Pied Hornbill u c f u
Anthracoceros albirostris
Banded Kingfisher Lacedo pulchella r
Stork-billed Kingfisher Pelargopsis capensis u u u
White-throated Kingfisher u r r r
Halcyon smyrnensis
Pied Kingfisher Cer yle rudis (Note 7) f f
Blue-bearded Bee-eater Nyctyornis athertoni r
Asian Green Bee-eater Merops orientalis c f f
Blue-tailed Bee-eater Merops philippinus c r c
Chestnut-headed Bee-eater f f r u c
Merops leschenaulti
Indian Roller Coracias benghalensis u c c r u
Oriental Dollarbird Eurystomus or ientalis r
Coppersmith Barbet f u
Psilopogon haemacephalus
Blue-eared Barbet Psilopogon cyanotis f u
Green-eared Barbet Psilopogon faiostrictus u
Lineated Barbet Psilopogon lineat us f f f f
Heart-spotted Woodpecker r
Hemicircus canente
Greater Flameback u u
Chrysocolaptes guttacristatus
Common Flameback Dinopium javanense u u u u r
Rufous Woodpecker Micropternus brachyurus u
Greater Yellownape u
Chrysophlegma fla vinucha
Lesser Yellownape Picus chlorolophus u
Streak-throated Woodpecker r
Picus xantho pygaeus
Laced Woodpecker Picus vittatus r
Black-naped Woodpecker Picus gueri ni u u
Black-headed Woodpecker r f f u
Picus er ythropygius
Grey-capped Woodpecker f u
Picoides ca nicapillus
Yel low -c ro wne d Woo dp eck er u
Leiopicus mahrat tensis
Rufous-bellied Woodpecker u
Dendrocopos hyperythrus
Freck le-br easted Woodp ecker f u u
Dendrocopos analis
Collared Falconet Microhierax caerulescens r r
Blossom-headed Parakeet r r c
Psittacula roseata NT
Red-breasted Parakeet c c c c c c f
Psittacula alexandri NT
Vern al Ha nging Parro t Loriculus vern alis r r u
Banded Broadbill Eurylai mus harterti u
Blue-winged Pitta Pitta molu ccensis u u f
Golden-bellied Gerygone Gerygone sulphurea f
Common Woodshrike u f
Tephrodornis pondicerianus
Bar-winged Flycatcher-shrike u u
Hemipus picatus
Common Iora Aegithina tiphia u c c u f u
Small Minivet Peri crocotus cinna momeus u f c
Scarlet Minivet Pericrocotus fla mmeus r
Large Cuckooshrike Coracina javensis f u
Indochinese Cuckooshrike Lalage polioptera u
Brown Shrike Lanius cristatus u
Burmese Shrike Lanius collurioides c f
White-bellied Erpornis Erpornis zantholeu ca u r
Black-naped Oriole Oriolus chinensis r
Black-hooded Oriole Oriolus xanthornus f f u
Black Drongo Dicrurus macrocercus u u u
Ashy Drongo Dicrurus leucophaeus f u
Bronzed Drongo Dicrurus aeneus u u
Hair-crested Drongo Dicrurus hottentottus f f
Greater Racquet-tailed Drongo r c u c
Dicrurus paradiseus
Sunda Pied Fantail Rhipidura javanica c f
White-browed Fantail Rhipidura aureola f f
Black-naped Monarch Hypothymis azurea c c
Oriental Paradise Flycatcher u
Ter ps ip ho ne affi nis
Eurasian Jay Garrulus glandarius r
Red-billed Blue Magpie u u u
Urocissa erythror yncha
Rufous Treepie Dendrocitta vagabunda u
Racquet-tailed Treepie Crypsirina temia f f f u r
Large-billed Crow Corvus macrorhync hos u u u
Horsfield’s Bushlark Mirafra javanica (Note 8) c
Indochinese Bushlark Mirafra erythrocephala u c f
Asian Plain Martin Riparia chinensis (Note 9) c
Barn Swallow Hirundo rustica c u u
Wire-tailed Swallow Hirundo smithii (Note 10) u
Red-rumped Swallow Cecropis dau rica u
Burmese Nuthatch Sitta neglecta u f
Black-headed Bulbul Brachypodius atriceps r f
Black-crested Bulbul Pycnonotus flaviventris f c
Sooty-headed Bulbul Pycnonotus aurigaster c c c
Stripe -throated Bulbul Pycnonotus finlaysoni u f c
Yel low -v ent ed Bu lbu l Pycnonotus goiavier c c u
Streak-eared Bulbul Pycnonotus blandfordi c f f f f
Puff-throated Bulbul Alophoixus pallidus u
Species 1 2 3 4 5 6 7Species 1 2 3 4 5 6 7

92
Grey-eyed Bulbul Iole propinqua u
Dusky Warbler Phylloscopus fuscatus r
Thick-billed Warbler Arundinax aedon r
Black-browed Reed Warbler f
Acrocephalus bistrigiceps
White-browed Reed Warbler u
Acrocephalus tangorum VU
Oriental Reed Warbler f f u
Acrocephalus orientalis
Pallas’s Grasshopper Warbler r
Locustella cer thiola
Zitting Cisticola Cisticola juncidis u
Golden-headed Cisticola Cisticola exilis c f
Common Tailorbird Orthotomus sutorius u r u
Dark-necked Tailorbird c f c c
Orthotomus atrogularis
Brown Prinia Prinia polychroa c c
Rufescent Prinia Prinia rufescens f
Grey-breasted Prinia Prinia hodgsonii f f f
Yel low -b el lie d Pri nia Prinia fla viventris c f r
Plain Prinia Prinia inornata f r
Chestnut-capped Babbler Timalia pileata u
Pin-striped Tit Babbler Mixornis gularis c c c
Puff-throated Babbler Pellorneum ruficeps f
Abbott’s Babbler Malacocincla abbotti u
White-crested Laughingthrush f c
Garrulax leucolophus
Asian Fairy Bluebird Irena puella u
Dark-sided Flycatcher Muscicapa sibirica u
Asian Brown Flycatcher Muscicapa dauurica u
Oriental Magpie Robin Copsychus s aularis c u f u u
White-rumped Shama Kittacincla malabaricus f r f c
Tickell’s Blue Flycatcher Cyor nis t ic ke lli ae f f f
Bluethroat Cyan ec ul a s ve ci ca u
Green-backed Flycatcher Ficedula elisae r
Red-throated Flycatcher Ficedula alb icilla r
Pied Bushchat Saxicola caprata c c u
Common Hill Myna Gracula religiosa f
Black-collared Starling Gracupica nigricollis r r
Chestnut-tailed Starling Sturni a malabari ca c u f
Common Myna Acridotheres tristis u u
Burmese Myna Acridotheres burmannicus u
Great Myna Acridotheres grandis c f c u
Blue-winged Leafbird Chloropsis moluccensis r
Golden-fronted Leafbird Chloropsis aurifrons u u f
Thick-billed Flowerpecker Dicaeum agile u
Scarlet-backed Flowerpecker f u
Dicaeum cruentatum
Ruby-cheeked Sunbird r u u
Chalcoparia singalensis
Purple Sunbird Cinnyris asiaticus u f r f f
Olive-backed Sunbird Cinnyris jugularis u u u r u f
Crimson Sunbird Aethopyga siparaja f
Eastern Yellow Wagtail u
Motacilla tschutschensis
Mekong Wagtail Motacilla samveasnae NT f f
Paddyfield Pipit Anthus rufulus c u u
Plain-backed Sparrow Passer fl aveolus f u f
Baya Weaver Ploceus philip pinus f c u
Red Avadavat Amandava amandava f
White-rumped Munia Lonchura str iata f u u
Scaly-breasted Munia Lonchura punctulata c c c
Species 1 2 3 4 5 6 7 Species 1 2 3 4 5 6 7
Notes
(1) Both Chinese Pond Heron Ardeola bacchus and Javan Pond Heron A. speciosa occur in the area. We saw pond heron spp. in non-breeding
plumage on the Kampi river islands and O Spean wet grasslands. Chinese and Javan Pond Heron in breeding plumage were seen in O Spean
grasslands on 2 May.
(2) Taxonomy of the Purple Swamphen Porphyrio porphyrio complex is under debate. Several taxa are thought by some to be separate species
based on plumage, but evidence is conflicting; further research is needed (Eaton et al. 2016).
(3) The Red-necked Stint Calidris ruficollis is a widespread winter visitor and passage migrant in Cambodia, but with few previous records from
Kratie province (Goes 2013). We observed a single individual on Khang Lok Krau on 7 May.
(4) On 4 May we flushed a single snipe Gallinago sp. from a wet pasture near O Spean. Recordings of the flight call suggested that it was probably
a Pintail Snipe G. stenura. Snipe are regular winter visitors to Cambodia, but this record is later than the previous latest spring date for Pintail
Snipe (25 April) and Common Snipe G. gallinago (16 April).
(5) The taxonomy of migratory Asian cuckoos Cuculus spp. remains debated, with some recognising Himalayan Cuckoo C. saturatus and Oriental
Cuckoo C. optatus as separate species, whilst others consider them as races of C. saturatus. Identification of non-vocal birds in the field may
be impossible (Lindholm & Linden 2007), but the taxa apparently differ in their wintering distribution, with saturatus more likely to occur in
Cambodia. Individuals were seen once in the dry dipterocarp forest at O Kak village and once feeding on Koh Khlab. Here we follow Goes
(2013) in identifying them as saturatus on the basis of distribution.
(6) The identification of dark plumage swiftlets Aerodramus spp. in Cambodia has been complicated by the import of White-nest Swiftlets
A. fuciphagus for swiftlet nest farming (Poole 2010). This species is often indistinguishable from the native Germain’s Swiftlet A. ge rmani in
the field (Goes 2013). We frequently observed dark swiftlets Aerodramus spp. at our camp locations and follow Goes (2013) in not assigning
them to species.
(7) The Mekong channels are one of two population strongholds for Pied Kingfisher Ceryle r udis in Cambodia (Goes 2013). Timmins (2008) found
it to be relatively common and we also found it fairly common around the Kampi river islands, with up 12 seen daily. However, further north,
on the channels between Koh Khlab and Khang Lok Krau, it was uncommon, with only one or two birds seen during 45 km of river travel.
(8) The widespread Horsfield’s Bushlark Mirafra javanica is known in Cambodia only from a few locations in Kratie province. We found it fairly
common in wet grasslands near O Spean, apparently a new location (Goes 2013).
(9) Timmins (2008) saw Asian Plain Martin Riparia chinensis nesting colonies on the Kampi river islands and in the Koh Preal area—the only
known breeding sites in Cambodia. We also found up to 50 individuals near a potential nest site on the Kampi river islands on 28 April; small
flocks of 6–12 were seen daily on Koh Prum Mocha Rei.
(10) Wire-tailed Swallow Hirundo smithii is local in Cambodia, with the rocky channels between Kratie and Stung Treng being an important
nesting area, although Timmins (2008) estimated less than 100 individuals there. We only observed one to two Wire-tailed Swallows on three
occasions during two river trips between Koh Khlab and Khang Lok Krou on 7 and 10 May.
Surveys in 2018 along the Mekong River, northern Kratie province, Cambodia