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A short survey of the Meratus Mountains, South Kalimantan province, Indonesia: two undescribed avian species discovered

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Introduction
The avian biodiversity and endemism of Borneo
is impress ive, with some 50 endemic species
described from the island under earlier taxonomic
arrangements (e.g. Myers 2009), and up to twice
as many under the recently proposed taxonomic
arrangements of Eaton et al. (2016). Many of
these are monta ne specia lists, with a round 27
species endemic to Borneo’s highlands. Although
the mountai ns of the Malaysian states, Sabah
and Sarawak, are relatively well-explored, much
BirdingASIA 26 (2016): 107–113 107
LITTLEKNOWN AREA
A short survey of the Meratus Mountains,
South Kalimantan province, Indonesia: two
undescribed avian species discovered
J. A. EATON, S. L. MITCHELL, C. NAVARIO GONZALEZ BOCOS & F. E. RHEINDT
of the montane part of Indonesia’s Kalimantan
provinces has seldom been visited (Brickle et al.
2009). One of the least-known areas and probably
the most isolated mountain range (Davison 1997)
are the Meratus Mountains, South Kalimantan
province (Plates 1 & 2), a 140 km long north–south
arc of uplands clothed with about 2,460 km² of
submontane and montane forest, rising to t he
1,892 m summit of Gn Besar (several other peaks
exceed 1,600 m). Today, much of the range is
unprotected except for par ts of the southern
Plates 1 & 2. V iews across the Meratus Mountain range, South Kalimantan province, Kalimantan, Indonesia, showing extensive
forest cover, July 2016.
CARLOS NAVARIO BO COS CARLOS NAVARIO BO COS
end that lie in the Pleihari Martapura Wildlife
Reserve (Holmes & Burton 1987). The only previous
documented ornithological survey was made in
October 1996 by Davison (1997), mostly below
900 m, with only two nights spent camping near
the 1,686 m summit of Gn Karokangen; his surveys
were hampered by prolonged rainfall.
From 7–10 July 2016 we visited the central
part of the Meratus range be tween K adayang
villa ge (2.747°S 115.555°E) at 500 m, and t he
1,892 m summit of Gn Besar (2.712°S 115.625°E).
The habitat between 500 and 700 m was largely
cinnamon and rubber plantations, gradually giving
way to deg raded forest w ith much recent and
ongoing logging activity, until it became closed-
canopy forest above 900 m; we camped at 1,460 m
(2.718°S 115.599°E). Some surveys were curtailed
by heavy rain showers, although at other times we
exper ienced fine clear skies. During an estimated
120 man-hours of opportunistic bird surveys, 91
species were recorded (see Appendix 1), including
two apparently undescribed species, a white-eye
Zosterops sp. and a flycatcher Cyornis sp., as well
as an undescribed subspecies of Chestnut-hooded
Laughingthrush Garrulax treacheri. We also
observed eight species not previously recorded from
the area, evidently significant range extensions.
‘Meratus White-eye’ Zosterops sp. nov.
On o u r firs t da y we f ou n d a dis t i nc t ive
Zosterops taxon in a mixed feedi ng floc k—a
bird which we later found to be common above
Plates 3– 6. Four views of the new ta xon ‘Meratus White-eye’ Zosterops sp. nov., Gn Besar, Meratus Mountains, South Kalimantan
province, Kalimantan, 9 July 2016, showing yellow loral stripe or spot, slightly darker forehead and forecrown, and the striking bill
colouration.
JAMES EATON
108 A short survey of the Meratus Mountains, South Kalimantan, Indonesia: two undescribed avian species discovered
1,300 m. During our visit we encountered this taxon
in single-species flocks of up to 40 individuals
and also saw it in m ixed-s pecies flock s on a
regular basis. Although a formal description must
await the availability of biological material, we
here document this undescribed taxon from our
observations and images (Plates 3–6).
The size and structure of the new ta xon did
not differ noticeably from Hume’s White-eye Z.
auriventer (for revised taxonomy see Eaton et al.
2016), a species frequent ly encountered on the
lower slopes and familiar to all of us. However,
the new taxon is differentiated from other Bornean
upland white-eye species by its uniform yellowish-
olive plumage, including underparts. Its forehead,
crown, face, ea r-cove rt s and submoustachial
region are bright olive-green, althoug h slightly
darker on the a rea immediately above the broad
white eye-ring. The eye-ring is broadest below
the eye, with a narrow break at the lores. A thin
yellowish loral line or spot is located above the
narrow dark sub-loral line between gape and eye.
The chin and throat are brighter, merging into the
diffuse yellowish-olive median stripe through the
breast and belly. The nape, scapulars, flanks, wing-
coverts and upperparts are monotone olive-green,
while the primaries and seconda ries are golden-
olive with blackish fringes, forming a panel on the
closed wing. The rump and undertail-coverts are
bright yellow-olive, and rectrices blackish. The legs
are steel-grey and the iris is dark brown. Apart from
its distinctive plumage, the ‘Meratus White-eye’ is
notable for its striking bill colouration, the lower
mandible being pinkish-orange merging to greyish
at the tip and the upper mandible being darker
grey but with some pink ish-orange tones bleeding
through at the base. No sexual dimorphism was
observed. Presumed juveniles had duller grey bills
and possibly narrower eye-rings with a post-ocular
break. Like other Bornean white-eyes, the species
mostly sings at day-break and in the early morning.
Its dawn song is a warbling series of high-pitched
short notes, ending with a faster, lower-pitched
jumble and lasting 1–3 seconds. Its usual call is a
high-pitched, buzzy zip.
At similar a ltitudes in other parts of Borneo,
the Black-capped White-eye Z. atricapilla appears
to occupy a simila r niche to the ‘Meratus White-
eye’. However, atricapilla differs markedly, with its
extensive grey flanks, extensive black forecrown,
dark bill and pale iris. The song and part icularly
the lower-pitched call are also different. Davison
(1997) reported that the Black-capped White-eye
was common at 1,600–1,650 m on Gn Karokangen
an d this rec ord appe ared in t he subsequent
literatu re (e.g. Myers 2009, van Balen 2016).
However, his plumage descript ions leave no doubt
that he was in fact dealing with the new species.
The occ ur renc e of Black-capped Wh ite-eye in
the Meratus Mountains is unlikely, given that it
is usually conspicuous where it occurs. Another
Bornean montane white-eye species, the Mountain
Black-eye Z. emiliae, also remains unrecorded from
the Meratus Mountains.
‘Meratus Jungle Flycacher’ Cyornis sp. nov.
A female Cyornis sp. flycatcher found in the same
mixed-species flock as the first ‘Meratus White-
eyes’ also caused great interest because, despite
our extensive field experience of all the Cyornis
species known from Borneo and elsewhere in
South-East Asia, we were unable to identify the
bird to species level and images were obtained for
later evaluation. Then, the following morning, we
heard a typical Cyornis song and, although it was
unfamiliar to us, using playback we were able to
confirm that this was another undescribed taxon.
In all we recorded it five times between 900 and
1,300 m and obtained images of males and females
(Plates 7–9).
No biological material is available at this time,
rendering a formal description prematu re. The
following documentation is based on our field
notes, images obtained and sound recordings made.
Plate 7. Male ‘Meratus Jungle Flycatcher’ Cy orn is sp. nov.,
Meratus Mountains, South Kalimantan province, 8 July 2016.
JAMES EATON
BirdingASIA 26 (2016) 109
The new taxon is estimated to be sign ificantly
larger than the Bornean endemic taxon of the Hill
Blue Flycatcher complex C. banyumas montanus,
now Dayak Jungle Flycatcher C. montanus (Eaton
et al. 2016), and possibly Bornean Blue Flycatcher
C. superbus, now Bornean Jungle Flycatcher (Eaton
et al. 2016), although not quite as large as White-
tailed Flycatcher C. concretus.
The male’s upperparts, crown, forehead, face
and ear-coverts are a deep metallic blue typical
of most of the genus, with brighter iridescent
blue restricted to the forecrown. The chin, throat,
breast and flanks are powder-orange, while the
lower breast transit ions from orange to a clearly
demarcated dirty white, similar to the Hill Blue
Flycatcher taxon C. banymas coerulifrons of the
Thai-Malay Peninsula. The belly and undertail are
off-white in colour except for a small dusky-blue area
on the mid-flanks. A single outer rectrix was white,
but only on one side, presumably moult-related
(Plate 8). The female has a grey-brown head with
a paler narrow eye-ring, contrasting slightly with
the grey-brown upperparts and browner tail, and
a pale orange throat with a deeper orange breast;
the rest of the underparts resemble the male. Both
sexes have dark grey bills, significantly heavier
than C. [banyumas] montanus, approaching the
size of the bill of a Large-billed Blue Flycatcher C.
caerulatus, now Sunda Jungle Flycatcher (Eaton et
al. 2016). The legs are noticeably pale pink and the
iris is dark. The song of the new form is a warbling
series of 3–7 high-pitched, prolonged, glissading,
deliberate notes ending with faster, lower notes,
lasting 1–3 seconds. Calls vary from soft, dry clicks
and chirps to a n urgent two-syllable chee-weeet
alarm call, up-slurred on the first syllable.
Borneo has four other endemic Cyor ni s
flycatchers (Eaton et al. 2016), all easily separable
from the new taxon: Bornean Blue Flycatcher males
show an extensive, shining electric blue forehead
to nape and lower back to rump, with underparts
deeper, more extensive orange. Male Large-billed
Blue Flycatchers are separated by a black chin,
brighter lower back and rump, and orange belly.
Male Mangrove Blue Flycatchers C. rufigastra,
restricted to coastal lowlands, show more extensive
electric blue on the forehead, extensive rufous-
orange underparts, a black chin and black ta il.
Male Malaysian Blue Flycatchers C. turcosus have
an entirely blue upper breast.
We cons ider the new species a possible
replacement for the endemic taxon of the Hill
JAMES EATON
Plate 8. Male ‘Meratus Jungle Flycatcher’, Meratus Mountains,
South Kalimantan province, 8 July 2016, showing only one
white rectrix.
Plate 9. Female ‘Meratus Jungle Flycatcher’, Meratus
Mountains, South Kalimantan province, 7 July 2016.
JAMES EATON
110 A short survey of the Meratus Mountains, South Kalimantan, Indonesia: two undescribed avian species discovered
Blue Flycatcher complex C. montanus (now Dayak
Jungle Flycatcher), although the male of the latter
species is easily separated by its black chin, orange
bel ly and shorter tail. Other members of this
species complex are also worthy of comparison.
The Javan endemic banyumas and ligus bot h
have extensive orange underparts, including belly
and undertail-cover ts, wh ilst the Tha i-Malay
Peninsula taxon coerulifrons is much more similar
in appearance (but not in vocalisations), although
it exhibits more extensive areas of electric blue on
the forecrown and wings. The female is separated
from all the above species by its narrow eye-ring,
although separation from other taxa of the C.
banyumas complex requires further study.
Other noteworthy species observed
Bornean Barbet Psilopogon eximius
Range extension: one seen and several heard
between 900 m and 1,300 m; the nearest previous
records are from Barito Ulu (B. van Balen in litt.),
over 300 km to the north-west.
Bornean Whistler Pachycephala hypoxantha
Range extension: fairly common above 1,100 m,
wit h several individuals seen and heard; over
300 km south-east of the previous most southerly
records from Barito Ulu (B. van Balen in litt.).
Grey-chinned Minivet Pericrocotus solaris
Range extension: occ asional ly recorded above
900 m; previously recorded only as far south as the
Menyapa Mountains, some 450 km away (Brickle
et al. 2009).
Bornean Treepie Dendrocitta cinerascens
Ra ng e extension: commonly rec ord ed ab ove
1,100 m; nearest previous records were from the
Mahakam drainage, over 260 km away (B. van
Balen in litt.).
Penan (Chestnut-vented) Bulbul
Alophoixus ruficrissus
Both races of this Bornean endemic have rich
reddi sh- brown underparts; however, we s aw
several birds all with slightly paler, yellow-
tinged underpa rts, which may be an undescribed
subspecies.
Chestnut-hooded Laughingthrush
Garrulax treacheri
Previously recorded by Davison (1997) between
1,200 and 1,600 m; we saw small numbers between
1,100 and 1,720 m. They differed from the three
subspecies known from north and central Borneo
in having peachy-buff (not buff-grey) underparts,
lacking pale streaking on the breast and showing
distinctive white flecking below the eye (Plate 10),
and may represent an undescribed subspecies.
Bornean Stubtail Urosphena whiteheadi
Range extension: at least seven individuals were
encountered, of which three were sound-recorded.
Notably, all birds heard gave a single drawn-out
introductory tseeee instead of the two introductory
tsit-tsit notes recorded in the rest of the species’s
range (B. van Balen in litt.). Although the two
birds seen well both appeared rather pale-breasted
and more distinctly grey-spotted than most birds
observed in northern Borneo, the species’s plumage
appears to be variable and further work is needed
to confirm whether this is an undescribed taxon.
The previous most southerly record was from the
Menyapa Mountains, some 450 km away (Brickle
et al. 2009).
Fruithunter Chlamydochaera jefferyi
Range extension : very common, with over 60
recorded b et ween 1,300 and 1,800 m. Many
of the ridge-top trees were f ru iti ng, which is
probably why the large numbers, including many
immatures, were present; the nearest previous
rec ord was f rom Buk it Baka in the Schwane r
Plate 10. Chestnut-hooded Laughingthrush Garrulax trea cheri,
Meratus Mountains, South Kalimantan province, 10 July 2016,
showing peachy-buff underparts, lack of streaking on the
breast and white flecking below th e eye.
CARLOS NAVARINO B OCOS
BirdingASIA 26 (2016) 111
range, on the border between Cent ral and West
Kalimantan provinces, more than 400 km away
(B. van Balen in litt.).
Bornean Shortwing Brachypteryx erythrogyna
Ra nge ex ten sion: several birds of both sexes
wer e hear d and see n above 1,300 m and al l
appeared similar to birds from Mt Kinabalu, Sabah.
Previously the most southerly record in Kalimantan
was from the Menyapa Mountains (Brickle et al.
2009).
Bornean Leafbird Chloropsis kinabaluensis
Range extension: a single female, identified by its
black throat with well-demarcated bright viridian
(rather than yellow) mask surround, was recorded
at 900 m; previously recorded only as far south
as the Menyapa Mountains (Brickle et al. 2009).
Conclusion
Our discovery of at least two undescribed taxa
co nf i rms t hat t he a vi fauna o f the Me ra tu s
Mountains, South Kalimantan province, is very
lit tle known. The ran ges of the new ta xa are
unknown and they may be restricted to this area.
Given the brevity of our visit, it is possible that
other significant findings await observers able to
explore these mountains, particularly the areas
between t he two main ridges of the range.
Editors’ note : In BirdingASIA 24 we were able to
produce our regular taxonomic review covering
developments up to the end of 2014. Due to other
commitments our regular contributors have been
unavailable in 2016 and this year has seen two
large contributions to Asian taxonomy in the form
of Birds of the Indonesian Archipelago (Eaton et
al. 2016) and the HBW and BirdLife International
illustrated checklist of the birds of the world, Volume
2 Passerines (del Hoyo & Collar 2016). This paper
utilises conclusions from Eaton et al. (2016);
however, we have where possible and appropriate
cross-referenced Appendix 1 with del Hoyo & Collar
(2016) to help readers who are ‘getting to grips’
with these new departures in taxonomy. As usual
in such circumstances we seek to remain neutral
and the outlining of proposals does not indicate
adoption by or opinion of the Oriental Bird Club.
References
van Balen, B. (2016) Black-capped White-eye (Zosterops atricapilla). HBW
Alive (h ttp :// ww w.h bw. co m/n od e/6 0170 a cce sse d o n 02 /08 /2 016).
Brickle, N. W., Eaton, J. A. & Rheindt, F. E. (2010) A rapid bird sur vey of the
Menyapa mountains, East Kalimantan, Indonesia. Forktail 2 6: 31– 41.
Davison, G. W. H. (1997) Bird observations in the Muratus Mountains,
Kalimantan Selatan. Kukila 9: 114–121.
Eaton, J. A., van Balen, B., Brickle, N. W. & Rheindt, F. E. (2016) Birds of the
Indonesian archipel ago. Barcelona: Lynx Edicions.
Holmes, D. A. & Burton, K. (1987) Recent notes on the avifauna of
Kalimantan. Kukila 3: 2–32.
del Hoyo, J. & Collar, N. J. (2016) HBW and BirdLife International illustrated
checklist of the birds of the world, Volume 2 Passerines. Barcelona:
Lynx Edicions.
Mann, C. F. (2008) T he bi rds o f Born eo: a n ann otat ed ch eck list .
Peterborough: British Ornithologists’ Union. Checklist 23.
Myers, S. (2009) Birds of B orneo. London: New Holland.
J. A. EATON
Kota Damansara, Casa Indah 1, Petaling Jaya
Selangor Malaysia
Email: james.birdtourasia@gmail.com
S. L. MITCHELL
Topham Farm, Topham Ferry Lane, Sykehouse
Goole, DN14 9BQ, UK
Email: Simonleomitchell@gmail.com
C. NAVARIO GONZALEZ BOCOS
Plaza de la Libertad 3 2b, 47002 Valladolid, Spain
Email: cnbocos@gmail.com
F. E. RHEINDT
Department of Biological Science
National University of Singapore
14 Science Drive 4, Singapore 117543
Email: frankrheindt@gmail.com
112 A short survey of the Meratus Mountains, South Kalimantan, Indonesia: two undescribed avian species discovered
Appendix 1
List of species recorded during survey. Species nomenclature and taxonomy follows Eaton et al. (2016). Equivalent nomenclature
and taxonomy following del Hoyo & Collar (2016) shown in semi-bold in brackets. * = new range extension
Crested Partridge (Roulroul) Rollulus rouloul
Little Cuckoo Dove Macropygia ruficeps
Sunda Cuckoo Cuculus lepidus
Sunda Brush Cuckoo Cacomantis sepulcralis
(Brush Cuckoo C. variolosus sepulcralis)
Asian Palm Swift Cypsiurus balasiensis
Swiftlet sp. Aerodramus sp.
Bornean Frogmouth Batrachostomus mixtus
Crested Serpent Eagle Spilornis cheela
Blyth's Hawk Eagle Nisaetus alboniger
Rufous-bellied Eagle Lophotriorchis kienerii
Sunda Owlet Glaucidium sylvaticum
(Collared Owlet G. brodiei sylvaticum)
Mountain Scops Owl Otus spilocephalus
Barred Eagle Owl Bubo sumatranus
Diard's Trogon Harpactes diardii
Bushy-crested Hornbill Anorrhinus galeritus
Rhinoceros Hornbill Buceros rhinoceros
Wreathed Hornbill Rhyticeros undulatus
Gold-whiskered Barbet Psilopogon chrysopogon
Mountain Barbet Psilopogon monticola
Blue-eared Barbet Psilopogon australis
(Black-eared Barbet P. d uv auc eli i)
* Bornean Barbet Psilopogon eximius
Rufous Piculet Sasia abnormis
Maroon Woodpecker Blythipicus rubiginosus
Banded Yellownape Chrysophlegma miniaceum
(Banded Woodpecker C. miniaceum)
Checker-throated Yellownape Chrysophlegma mentale
(Chequer-throated Yellownape C. humii)
Crimson-winged Woodpecker Picus puniceus
Grey-capped Pygmy Woodpecker Picoides canicapillus
Banded Kingfisher Lacedo pulchella
(Black-faced Kingfisher L. melanops)
Blue-crowned Hanging Parrot Loriculus galgulus
Green Broadbill Calyptomena viridis
Black-and-yellow Broadbill Eurylaimus ochromalus
Bornean Banded Pitta Hydrornis schwaneri
Golden-bellied Gerygone Gerygone sulphurea
Blyth's Shrike-vireo Pteruthius aeralatus
(White-browed Shrike Babbler P. ae ral atu s)
(White-bellied) Erpornis Erpornis zantholeuca
* Bornean Whistler Pachycephala hypoxantha
Bar-winged Flycatcher-shrike Hemipus picatus
* Grey-chinned Minivet Pericrocotus solaris
White-throated Fantail Rhipidura albicollis
Spotted Fantail Rhipidura perlata
Ashy Drongo Dicrurus leucophaeus
Black-naped Monarch Hypothymis azurea
Jay Shrike (Crested Shrike Jay) Platylophus galericulatus
* Bornean Treepie Dendrocitta cinerascens
Grey-headed Canary-flycatcher Culicicap a ceylon ensis
Scaly-breasted Bulbul Pycnonotus squamatus
Black-headed Bulbul Microtarsus (Brachypodius) atriceps
Penan (Chestnut-vented) Bulbul Alophoixus ruficrissus
Cinereous Bulbul Hemixos cinereus
(Green-winged Bulbul H. connectens)
Streaked Bulbul Ixos malaccensis
Striped Tit-babbler Mixornis gularis
(Bold-striped Tit-babbler M. bornensis)
Sunda Scimitar Babbler Pomatorhinus bornensis
(Chestnut-backed Scimitar Babbler P. m ont anu s)
Grey-throated Babbler Stachy ris nigriceps
Moustached Babbler Malacopteron magnirostre
Tem mi nck 's Ba bb le r Pellorneum pyrrogenys
Brown Fulvetta Alcippe brunneicauda
Chestnut-hooded Laughingthrush Garrulax treacheri
Chestnut-crested Yuhina Staphida everetti
Hume's White-eye Zosterop s aurivente r
Meratus White-eye Zosterops sp. nov.
Sunda Warbler Seicercus grammiceps
(Yellow-breasted Warbler Phylloscopus montis)
Mountain Leaf Warbler Seicercus trivirgatus
(Mountain Warbler Phylloscopus trivirgatus)
* Bornean Stubtail Urosphena whiteheadi
Bamboo Bush (Yellow-bellied) Warbler Abroscopus superciliaris
Mountain (Tailorbird) Leaftoiler Phyllergates cucul latus
Ashy Tailorbird Or thotomus ruficeps
Dark-necked Tailorbird Orthotomus atrogularis
Rufous-tailed Tailorbird Orthotomus sericeus
Velvet-fronted Nuthatch Sitta frontalis
* Fruithunter Chlamydochaera jeeryi
Verd iter ( Flycatcher) Warbling Flycatcher Eumyias thalassinus
Indigo (Flycatcher) Warbling Flycatcher Eumyias indigo
Little Pied Flycatcher Ficedula wester manni
Meratus Jungle Flycatcher Cyornis sp. nov.
Bornean (Blue Flycatcher) Jungle Flycatcher Cyornis superbus
Bornean Shortwing Brachypteryx erythrogyna
Bornean Shade-dweller Vau riel la g ular is
(Eyebrowed Jungle Flycatcher V. g ul ar is)
* Bornean Leafbird Chloropsis kinabaluensis
Asian Fairy Bluebird Irena puella
Yel low -b rea st ed Flo wer pe cke r Prionochilus maculatus
Yel low -r ump ed Fl owe rp eck er Prionochilus xa nthopygius
Orange-bellied Flowerpecker Dicaeum trigonostigma
Bornean (Black-sided) Flowerpecker Dicaeum monticolum
Ruby-cheeked Sunbird Chalcoparia singalensis
Brown-throated Sunbird Anthreptes malacensis
Van Hasselt 's (Maroon-bellied) Sunbird Leptocoma brasiliana
Tem mi nck 's Su nb ird Aethopyga temminckii
Grey-breasted Spiderhunter Arachnothera modesta
Little Spiderhunter Arachnothera longirostra
Purple-naped Spiderhunter Arachnothera hypogrammica
Dusky Munia Lonchura fuscans
BirdingASIA 26 (2016) 113
... There continues to be a dearth of knowledge on this radiation across the core of its Asian distribution due to limited sampling and lack of genetic data. In particular, it is crucial to unravel the phylogenetic affinities of white-eyes distributed across the Indonesian archipelago, which -comprising more than 17,000 islands -is the largest archipelago in the world and harbors about 20 endemic Zosteropsspecies (Fig. 1), including two undescribed species that were discovered in the last two decades (Eaton et al. 2016;O'Connell et al. 2019). The high density of Zosterops species across the Indonesian archipelago hints at the possible importance of this region in white-eye evolution. ...
... We expanded our clade assignment to 30 Zosterops taxa not sampled in our study but found to be embedded within one of the three main clades with high bootstrap support ( >90%) by at least one previous study (Table S2). We also included two undescribed Zosterops species in this expanded clade assignment (Eaton et al. 2016;O'Connell et al. 2019). ...
... atricapilla and Z. auriventer ), montane endemics (Z. emiliae and an undescribed white-eye from the Meratus range (Eaton et al. 2016)), and coastal woodland species (Z. simplex ). ...
... This is particularly true of birds in the Meratus range of south-east Borneo. These mountains have rarely been visited by ornithologists or birdwatchers (Davison 1997, Eaton et al. 2016a Louisiana State University Museum of Natural Science (LSUMNS) and the Museum Zoologicum Bogoriense, Indonesian Institute of Sciences (MZB), conducted a joint expedition to Mt. Besar on 1-19 May 2017. The primary purpose was to obtain molecular and morphological specimens for use in ongoing studies of Sundaic avian biogeography (e.g., , Chua et al. 2017, Lim et al. 2017. ...
... Expedition.-Our team comprised three researchers from LSUMNS (SBS, RCB, FHS), a researcher (TH) and field technician from MZB (Suparno), and a variety of local guides and porters. Like Davison (1997) and Eaton et al. (2016a), we approached Mt. Besar from Loksado in the Hulu Sungai Selatan regency of South Kalimantan province. ...
... Lemon-bellied White-eye Zosterops chloris.-This is one of the taxa identified as a new species by Eaton et al. (2016a). ND2 comparisons with 45 other species of white-eyes, including the genera Zosterops, Lophozosterops, Speirops and Chlorocharis (mostly from Moyle et al. 2009), reveal the Meratus population to be most closely related to Z. chloris (ND2 divergence 2.69%). ...
Article
Full-text available
The Meratus Mountains of south-east Borneo are biogeographically interesting due to their isolation and potential endemicity. However, Meratus' birds have never been quantitatively surveyed or collected, so we know little of their community structure or taxonomy. In May 2017, we visited Mt. Besar in the Meratus range to assess its avifauna and collect specimens for phylogeographic study. Here, we report on Mt. Besar's avifauna and provide preliminary ND2-sequence assessments of their relationships. We recorded 89 species, of which we collected 68 species; 17 represented distributional extensions. Mt. Besar's avian community is depauperate compared to Borneo's main mountains, and several of its species exhibit unusual elevational abundance patterns. We attribute these findings to the range's small area, low elevation, isolation from other mountains, depleted surrounding native lowland forest, and exploitation for food and pet-trading. ND2 comparisons indicate that at least 12 Meratus species exhibit population structure that merits additional phylogeographic study.
... species (Davison 1996, Eaton et al. 2016b, Shakya et al. 2018) despite having made other significant discoveries. Davison (1996) and Eaton et al. (2016b) visited the Meratus Mountains for a relatively short duration and covered lower elevations only briefly. ...
... species (Davison 1996, Eaton et al. 2016b, Shakya et al. 2018) despite having made other significant discoveries. Davison (1996) and Eaton et al. (2016b) visited the Meratus Mountains for a relatively short duration and covered lower elevations only briefly. Shakya et al. (2018) managed to conduct 19 days of mist-netting work at elevations of 500, 1,500 and 1,350 m on Gunung (= Mount) Besar. ...
... There continues to be a dearth of knowledge on this radiation across the core of its Asian distribution due to limited sampling and lack of genetic data. In particular, it is crucial to unravel the phylogenetic affinities of white-eyes distributed across the Indonesian archipelago, which -comprising more than 17,000 islands -is the largest archipelago in the world and harbors about 20 endemic Zosterops species (Figure 1), including two species that were discovered in the last two decades and remain undescribed (Eaton et al., 2016;O'Connell et al., 2019). The high density of Zosterops species across the Indonesian archipelago hints at the possible importance of this region in whiteeye evolution. ...
... atricapilla and Z. auriventer), montane forest (Z. emiliae and a still undescribed white-eye from the Meratus range Eaton et al., 2016), and coastal woodland (Z. simplex). ...
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Archipelagoes serve as important 'natural laboratories' which facilitate the study of island radiations and contribute to the understanding of evolutionary processes. The white-eye genus Zosterops is a classical example of a 'great speciator', comprising c. 100 species from across the Old World, most of them insular. We achieved an extensive geographic DNA sampling of Zosterops by using historical specimens and recently collected samples. Using over 700 genome-wide loci in conjunction with coalescent species tree methods and gene flow detection approaches, we untangled the reticulated evolutionary history of Zosterops , which comprises three main clades centered in Indo-Africa, Asia, and Australasia, respectively. Genetic introgression between species permeates the Zosterops phylogeny, regardless of how distantly related species are. Crucially, we identified the Indonesian archipelago, and specifically Borneo, as the major centre of diversity and the only area where all three main clades overlap, attesting to the evolutionary importance of this region.
... In the same vein, vocal similarities arguably smaller than the ones observed between our robins have been documented among a number of Cyornis jungle-flycatchers (Gwee et al., 2019) that are known to be genetically deeply diverged (e.g. Cyornis montanus and an undescribed form from the Meratus mountains (Shakya et al., 2018;Eaton et al., 2016b). These cases illustrate that the vocal differences here documented between Javan and Sumatran Blue ...
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Southeast Asian avifauna is under threat from both habitat loss and illegal poaching, yet the region’s rich biodiversity remains understudied. Here, we uncover cryptic species-level diversity in the Sunda Blue Robin (Myiomela diana), a songbird complex endemic to Javan (subspecies diana) and Sumatran (subspecies sumatrana) mountains. Taxonomic inquiry into these populations has previously been hampered by a lack of DNA material and the birds’ general scarcity, especially sumatrana which is only known from few localities. We demonstrate fundamental bioacoustic differences in courtship song paired with important distinctions in plumage saturation and tail length that combine to suggest species-level treatment for the two taxa. Treated separately, both taxa are independently threatened by illegal poaching and habitat loss, and demand conservation action. Our study highlights a case of underestimated avifaunal diversity that is in urgent need of revision in the face of imminent threats to species survival.
... Probably so. There are photographs of a distinct flowerpecker (the "Spectacled Flowerpecker") from Danum Valley (Edwards et al. 2009) and also of two possibly new species in the Meratus Mountains of southeastern Kalimantan (Eaton et al. 2016, Shakya et al. 2018. ...
Article
We describe two new bird species from the Meratus Mountains of southeastern Borneo, Indonesia: a jungle-flycatcher (genus Cyornis) and a white-eye (genus Zosterops). Our descriptions are based on comparisons of plumage, mitochondrial ND2 DNA sequences, and vocalizations of the new species and their congeners. The new Meratus jungle-flycatcher is most closely related to Cyornis montanus but morphologically distinguished by lighter blue on the upperparts and more whitish and less reddish on the underparts. The new Meratus white-eye is most closely related to Zosterops chloris but distinguished by olive upperparts and darker underparts. Vocalizations and genetic divergence values also corroborate species status for both new taxa. Both new species are probably confined to the Meratus Mountains, which are currently surrounded by degraded lower elevation secondary woodland or converted agricultural landscape. They appear to have diverged from their sister species through geographic isolation in this remote mountain range compounded by altered population dynamics in a depauperate montane bird community. Although both species are relatively common in the restricted area of the Meratus Mountains, continued habitat alteration and the imminent threat of poaching may be in the process of endangering them. Therefore, we recommend the IUCN Red List status of “Vulnerable” for the new species based on criteria B1 and B2.
Article
White-eyes are an iconic radiation of passerine birds that have been the subject of studies in evolutionary biology, biogeography, and speciation theory. Zosterops white-eyes in particular are thought to have radiated rapidly across continental and insular regions of the Afro- and Indo-Pacific tropics, yet, their phylogenetic history remains equivocal. Here, we sampled 77% of the genera and 47% of known white-eye species and sequenced thousands of ultraconserved elements to infer the phylogeny of the avian family Zosteropidae. We used concatenated maximum likelihood and species tree methods and found strong support for seven clades of white-eyes and three clades within the species-rich Zosterops radiation.
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The first-ever Illustrated Checklist of the Birds of the World is really two works in one. It is a complete checklist whose taxonomy incorporates the most up-to-date information and an exhaustive methodology (Tobias et al. 2010) in an entirely systematic and consistent way. At the same time, it contains illustrations and distribution maps for every bird species in the world. This includes the original artwork from the HBW series, as well as hundreds of new illustrations, all in two compact volumes (Volume 1: Non-passerines & Volume 2: Passerines).
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We report on a rapid bird survey in the Menyapa Mountains of East Kalimantan Province, Indonesia. Six days were spent at altitudes of between 150 m and 1,600 m during November 2007. A total of 184 species were recorded including one new species for Kalimantan, one new for Indonesia, and several range extensions, highlighting the interest and importance of the Menyapa region. The status, distribution and taxonomy of several montane species are discussed in general, including species both detected and undetected by this survey.
Recent notes on the avifauna of Kalimantan
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Bornean (Blue Flycatcher) Jungle Flycatcher Cyornis superbus Bornean Shortwing Brachypteryx erythrogyna Bornean Shade-dweller Vauriella gularis (Eyebrowed Jungle Flycatcher V. gularis)
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