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PATTERNS OF VARIATION IN THE MOUNTAIN BLACKEYE (Chlorocharis emiliae) IN SELECTED

MOUNTAINTOPS IN SABAH AND SARAWAK, MALAYSIA

Dency Flenny anak Ausgustine Gawin

Master of Science (Molecular Ecology and Evolutionary Genetics)

2007

Pusat Khidmat Maklumat Akademik UriIVERSITI MALAYSIA SARAWAK

P. KNIDMAT MAKLUMAT AKADEMIK

iiiiiiiiiliTi11ýrýý PATTERNS OF VARIATION IN THE MOUNTAIN BLACKEYE (Chlorocharis emiliae) IN SELECTED

MOUNTAINTOPS IN SABAH AND SARAWAK, MALAYSIA

DENCY FLENNY ANAK AUGUSTINE GAWIN

A thesis submitted In fulfillment of the requirement for the degree of Master of Science

Faculty of Resource Science and Technology UNIVERSITI MALAYSIA SARAWAK

2007

Declaration

I declare that, except as acknowledge in the text, the work presented in the thesis is

entirely my own work and has not been submitted, either in part or in whole, for a degree at this or any other university.

Dency Flenny Anak Augustine Gawin August 2006

ii

To my beloved family and friends who know me

111

Acknowledgment

More than two years, since I took this project, there had been a tremendous opportunity

for me to learn a lot of new things that I never acquired during my undergraduate

studies. The evolution study and its connection to the ecology and variations within the

organisms has intrigued me to seek the answers for all the questions about life and to

make me understand more, that God created them with some specialties and purposes

for them to survive in this world. I would like to thank my supervisor, Associate

Professor Dr. Mustafa Abdul Rahman (Dr. Bob), who initiated this project. Without his

support and guidance, probably I could not manage to complete my thesis. Thousand

thanks to him for sharing his valuable scientific aptitudes and for being a good teacher

and friend to me.

I would also like to express my personal gratitude to the following: Researcher Officer of

Sabah Park, Mr. Maklarin bin Lakim and his assistant, Mr. Alin Biun, for granting

permission and assisting me in getting my fieldwork at Kinabalu National Park to work

in Mount Kinabalu National Park.

Thanks to Regional Manager of Sarawak Forestry Corporation (SFC), Miri Branch, Mr.

Abang Arabi and his staffs, Mr. Zaidi Mawek, Mr. Augustine Lai and Mr. Siduk Lejau

for their co-operation during my fieldwork at Mount Mulu National Park. I would also

like to thank Sarawak Forestry Department (SFD) for granting permission to do

sampling.

iv

Director of Institute of Biodiversity, Environmental and Conservation (IBEC), Associate

Professor Dr. Andrew Alek Tuen for letting me to use the IBEC Molecular Laboratory

and providing a small fund for my fieldwork at Mount Pueh, Semantan and Associate

Professor Dr. Mohd Tajuddin Abdullah of UNIMAS for commenting my project and

making some references available.

Dr. Charles Leh of Sarawak Museum and Mr. Jafit of Sabah Museum for allowing me to

study the dry skin samples of mountain blackeye. Dr. Awang Ahmad Sallehin, Madam

Benardine Jeffrey and Mr. Faisal Ali for giving me ideas and assistance in doing the

cloning works. The laboratory assistants, Mr. Isa bin Sait and Mr. Raymond Patrick Atet

from UNIMAS, Mr. Duwin and Mr. Sutar of Kampung Siru Dayak and Mr. Kevin of

Kampung Tebakang Bidayuh for helping me in making my fieldwork a successful trip.

Also, the IBEC and Faculty of Resource Science and Technology (FRST), UNIMAS

administrative staffs for your administrative support. Miss Goh Wei Lim, Miss Imelda

Vivian Paul and her family in Inanam, Sabah for their unlimited assistance and support.

I cherish our friendship.

My love to my family and especially to my mummy, Madam Bertha Renus, thanks for

your support and encouragement. Last and not least, my heartful appreciation to

Camillus Benno Alian, you are my inspiration for me in taking the post-graduate study

in UNIMAS. I will always remember our friendship.

This project was supported by Universiti Malaysia Sarawak (UNIMAS) Fundamental

Research Grant 248/ 2001 (07) and 01(121)/ 510/ 05 (09).

V

Abstract

Mountain blackeye (Chlorocharis emiliae), an endemic spesies to Borneo, is commonly

found above 1,600 m above sea level. The known populations of this montane resident

included: Mount Kinabalu and Mount Trus Madi in Sabah, Mount Mulu, Mount Murud,

Tama Abo Range and Pueh Range in Sarawak, Maga mountains between Sabah and

Sarawak border and Mount Nyiut, in Kalimantan, Indonesia. This spesies is divided into

four sub-spesies; C. e. emiliae, C. e. trinitiae, C. e. fusciceps and C. e. moultoni. The

division of mountain blackeye into four sub-spesies has triggered many questions such as

how the spesies diverged morphologically, and when the diversification occur, and what

are the factors that contribute to the sub-specific variation of that spesies. Probably, the

differentiation could be due to the natural selection through adaptation processes and/ or

neutral process via random genetic drift within or between populations. /

The aim of this study was to investigate the patterns of variation among isolated

populations of the mountain blackeye in Borneo by analyzing selected morphological

characters and molecular data. The populations of mountain blackeyes included in this

study were (1) Mount Kinabalu, (2) Mount Trus Madi, (3) Mount Murud, (4) Mount Mulu

and (5) Pueh Range. The external morphological characters included tarsus length (TR),

wing length (WL) and wing span (WS), tail length (TA), total length (TL), bill length

(BL), bill depth (BD), bill width (BW) and head + bill (HB) were measured and analysed

for the morphological analysis. As for molecular analysis, samples were taken from three

populations; (1) Mount Kinabalu, (2) Mount Murud and (3) Mount Mulu. The third

domain of Control Region (CR) of mountain blackeye was utilized for the molecular

analysis.

V1

The numeric analytical results of morphological characters between the mountain

blackeyes populations in Borneo showed that, the bill length trait was highly significant

character than the other morphs, including the non-bill characters. In addition, the bill

length is the first character that contributed to the patterns of variation between the

selected populations and thus regarded as the most `plastic' morphological characters in

mountain blackeye. This finding was probably related to the feeding performance and

the adaptation of this spesies to the environmental elements. The wing length, tail and

tarsus characters of mountain blackeye even showed significant differences between the

populations in Borneo. The results showed that mountain blackeyes in Mount Kinabalu

population have a larger body than the other populations. Probably, the variations in

non-bill characters of mountain blackeye are due to the adaptation to the climatic

temperature and air pressure.

Results from the molecular analysis, revealed that Mount Mulu and Mount Murud

populations are genetically close. The results support the taxanomic classification which

those two populations belong to the same sub-spesies, C. e. moultoni. The sub-spesies

emiliae in Mount Kinabalu population has substantially diverged from the sub-spesies

moultoni of the Mount Mulu and Mount Murud populations. It was suggested that, the

two populations in the northern Sarawak were connected during the global cooling of the

Pleistocene period. During that time, the montane vegetation in Borneo was expended

and this led to the large dispersion of mountain blackeye farther than their recent

restricted areas. Based on the molecular analysis, the Mount Murud population is more

important compared to Mount Kinabalu and Mount Mulu in terms of the conservation

due to its genetic diversity. The Mount Kinabalu could be identified as a separate

`Management Unit' among the three populations.

vii

In conclusion, the study has demonstrated some components of the biogeographic forces

that must be quantified in order to identify the contemporary mechanisms that involve

in the radiation and evolution of the endemic bird spesies in Borneo. In addition, this

study also showed that the historical and contemporary mechanisms are connected to

each other and worked in unison to form the present geographic structure of avian

spesies within this region. Perhaps in future this study will be a platform for future

research on evolutionary theory within biogeographically distributed spesies which

emphasize more on the Southeast Asian region.

viii

Abstrak

Burung Gunung Bermata Hitam (Chlorocharis emiliae) yang merupakan spesies endemik

di Borneo, selalu dijumpai dikawasan melebihi 1,600 m dari paras aras laut. Populasi-

populasi burung tersebut yang setakat ini telah direkodkan ialah: Gunung Kinabalu and

Gunung Trus Madi di Sabah, Gunung Mulu, Gunung Murud, Banjaran Tama Abo di

Sarawak, Pergunungan Maga yang terletak di antara sempadan Sabah dan Sarawak

dan Gunung Nyiut di Kalimantan, Indonesia. Spesies ini dibahagikan kepada empat

sub-spesies: C. e. emiliae, C. e. trinitiae, C. e. fusciceps dan C. e. moultoni. Pembahagian

spesies ini kepada empat sub-spesies telah mencetuskan banyak persoalan-persoalan

seperti bagaimana spesies ini bercapah dari segi morpologinya dan bilakah pecahan ini

berlaku dan apakah faktor-faktor yang menyumbang kepada pembahagian sub-spesies

ini. Kemungkinan perbezaan ini disebabkan oleh pilihan secara semulajadi melalui

proses adaptasi dan / atau proses neutral melalui hanyutan genetik secara rawak di

dalam atau di antara populasi-populasi spesies tersebut.

Matlamat kajian ini ialah untuk menyiasat corak-corak variasi di antara populasi-

populasi terasing burung ini di Borneo melalui analisis morpologi bagi ciri-ciri yang

terpilih dan juga melibatkan data-data molekul. Populasi populasi spesies yang dipilih

bagi kajian ini ialah: (1) Gunung Kinabalu, (2) Gunung Trus Madi, (3) Gunung Murud,

(4) Gunung Mulu dan (5) Banjaran Pueh. Ciri-ciri morpologi luaran yang diukur dan

dianalisis untuk analisis morpologi termasuklah panjang kaki (TR), panjang sayap (WL)

dan panjang sebaran sayap (WS), panjang ekor (TA), panjang keseluruhan badan (TL),

panjang paruh (BL), kedalaman paruh (BD), lebar paruh (BW) dan kepala + paruh (HB).

Bagi analisis molekul, sampel-sampel DNA diambil dari tiga populasi-populasi yang

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dipilih iaitu: (1) Gunung Kinabalu, (2) Gunung Murud dan (3) Gunugn Mulu. Domain

Ketiga `Control Region (CR)' spesies ini digunakan untuk analisis molekular.

Keputusan daripada analisis ciri-ciri morpologi di antara populasi-populasi Burung

Gunung Bermata Hitam menunjukkan ciri panjang paruh adalah yang paling sinifikan

dibandingkan dengan ciri-ciri yang lain termasuklah ciri-ciri bukan paruh. Tambahan,

panjang paruh merupakan ciri yang pertama sekali menyumbangkan kepada corak-

corak variasi di antara populasi-populasi yang terpilih dan ini membolehkan ciri

tersebut dipilih sebagai ciri yang paling elastik untuk spesies ini. Penemuan ini berkait

rapat dengan tabiat permakanan burung ini dan juga adapatasinya kepada unsur-unsur

alam sekitar. Panjang sayap, ekor dan kaki bagi burung ini juga menunjukkan

perbezaan yang ketara di antara populasi-populasi di Borneo. Keputusan ini

menunjukkan burung Gunung Bermata Hitam bagi populasi di Gunung Kinabalu

mempunyai saiz badan yang lebih besar dibandingkan dengan populasi-populasi lain.

Kemungkinan, variasi-variasi bagi ciri-ciri bukan paruh bagi burung ini adalah

disebabkan adaptasinya kepada suhu persekitaran dan juga tekanan udara.

Keputusan-keputusan daripada analisis molekular menunjukkan populasi-populasi di

Gunung Mulu dan Gunung Murud adalah berhubung rapat dari segi genetik.

Keputusan-keputusan tersebut menyokong klasifikasi taxanomi yang menunjukkan

kedua-dua populasi tersebut adalah dari sub-spesies yang sama, C. e. moultoni. Sub-

speseis emiliae dari populasi di Gunung Kinabalu telah terpisah dari sub-spesies

moultoni dari populasi-populasi di Gunung Mulu dan Gunung Murud. Berdasarkan

kepada keputusan tersebut, kedua-dua populasi di utara Sarawak tersebut pernah

bertemu semasa tempoh penyejukan global pada zaman Pleistocene. Pada zaman

X

tersebut, vegetasi pergunungan di Borneo mungkin tersebar luas dan ini menyebabkan

penyebaran yang meluas bagi spesies ini sehingga melangkaui kawasan-kawasan yang

didiaminya sekarang. Berdasarkan kepada analisis molekular tersebut, populasi di

Gunung Murud adalah lebih penting dibandingkan dengan populasi-populasi di

Gunung Kinabalu dan Gunung Mulu dari segi pemuliharaan kepelbagaian genetik.

Gunung Kinabalu boleh diidentifikasikan sebagai satu `Unit Pengurusan' yang terasing

daripada ketiga-tiga populsi tersebut.

Kesimpulannya, kajian ini menunjukkan sebahagian komponen-komponen tekanan

biogeografik yang patut dinilai, di dalam mengenal pasti mekanisma kontemporari yang

terlibat di dalam evolusi bagi spesies-spesies burung endemik di Borneo. Tambahan pula,

kajian ini juga menunjukkan perkaitan dan kerjasama berlandaskan kepada

keharmonian di antara sejarah dan mekanisma kontemporari di dalam membentuk

struktur geografik pada zaman sekarang bagi spesies-spesies burung di rantau ini.

Diharap pada masa akan datang, kajian ini akan menjadi asas kepada pengkajian teori

evolusi di dalam penyebaran spesies biogeografik terutama sekali di rantau Asia

Tenggara.

xi

Pusat Khidmat Maklumat Akademik U1vIVERSITi MALAYSIA SARAWAK

Table of Contents

Title Page

Declaration

Dedication

Acknowledgement

Abstract

Abstrak

Table of Contents

List of Tables

List of Figures

Chapter 1 Introduction

1.1 Avifauna endemism in Borneo Island

1.2 Recent administration and political organization in the Borneo

1.3 Description of topography and climate of the highland in Borneo

1.3.1 Mountainous areas in Borneo

1.3.2 Mountains

1.3.3 Regional climate of Borneo Island

1.3.3.1 Mountain climate

1.4 Montane vegetation

1.5 Geological record of mountain ranges in Borneo Island

1.6 Species and speciation

1.6.1 Species concepts 1.6.2 Speciation and its related mechanisms

1.6.2.1 Allopatric speciation

1.6.2.2 Parapatric speciation

1.6.2.3 Sympatric speciation

1.6.3 The reproductive isolating mechanisms

1.7 The study species 1.7.1 General description of mountain blackeye

1.7.2 Distribution

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1.7.3 Sub-species

1.8 Specific aims and approach 1.8.1 Main objective and approaches

1.8.2 Specific hypotheses and predictions

Chapter 2 Materials and methods

2.1 Study outline

2.2 Sampling sites 2.2.1 Mount Kinabalu

2.2.2 Mount Trus Madi

2.2.3 Mount Murud

2.2.4 Mount Mulu

2.2.5 Pueh Range

2.3 Morphometric Part

2.3.1 Field techniques

2.3.1.1 Deployment of general mist-nets

2.3.1.2 Banding and measurements of birds

2.3.2 Museum specimens

2.3.3 Morphological analysis 2.3.3.1 Data conversion prior to analysis

2.3.3.2 Univariate analysis

2.3.3.3 Multivariate analysis

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2.3.3.3.1 Multivariate analysis of variance 48

2.3.3.3.2 Discriminant function analysis 48

2.4 Molecular Part 49

2.4.1 DNA sources 49

2.4.2 Molecular procedures 50

2.4.2.1 Laboratory materials 50

2.4.2.2 DNA extraction procedures 50

2.4.2.3 Amplification 52

2.4.2.4 Cloning procedures 54

2.4.2.4.1 Overnight preparation of a bacterial 54

X111

culture

2.4.2.4.2 Preparation of calcium chloride 56

(CaC12) competent cells 2.4.2.4.3 Transformation of bacterial plasmid 57

2.4.2.4.4 Extraction of plasmid 59

2.4.2.5 Purification of PCR products 60

2.4.2.5.1 DNA purification from agarose gels 60

2.4.2.5.2 DNA purification from PCR reaction 61

components

2.4.2.6 Sequencing 62

2.4.3 Molecular analysis 62

2.4.3.1 Sequence editing and alignment 62

2.4.3.2 Data analysis 62

Chapter 3 Results

3.1 Mountaintop avifauna diversity 65

3.2 Numerical morphological analysis 66

3.2.1 Univariate analysis between geographically isolated 66

populations

3.1.1.1 Live samples 66

3.1.1.2 Museum samples 67

3.2.2 Multivariate analysis 77

3.2.2.1 Multivariate analysis of variance (MANOVA) 77

3.1.2.1.1 Live samples 77

3.1.2.1.2 Museum samples 77

3.2.2.2 Discriminant function analysis (DFA) 78

3.3 Molecular analysis 81

3.3.1 Mitochondrial DNA (mtDNA) control region (CR) of 81

mountain blackeye

3.3.2 Phylogenetic analyses and geographic distribution 84

between populations 3.3.3 Statistical analysis of genetic structure within and 89

among populations

xiv

3.3.4 Test of population expansion 90

Chapter 4 Discussion

4.1 Morphological variation in mountain blackeye 92

4.1.1 Variation in bill morphology 92

4.1.2 Variation in non-bill characters 96

4.1.3 Geographical relationships of mountain blackeye 99

populations

4.1.4 Summary 100

4.2 Molecular variation in mountain blackeye 101

4.2.1 Population differentiation in relation to Pleistocene 102

periods

4.2.2 Genetic evolution within mountain blackeye 105

4.2.3 Sub-species divergence in mountain blackeye 107

4.2.4 Conservation implications 108

4.2.5 Summary 109

Chapter 5 Conclusions and recommendations 5.1 Conclusions 110

5.2 Recommendation for future studies 112

5.2.1 Further analyses on external morphological characters 112

5.2.2 Termination of gene flow and neutral mechanisms within 112

sub-species

References

List of Appendices

Appendix A

Appendix B

Appendix C

Appendix D

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xv

Appendix E

Appendix F

Appendix G

Appendix H

xvi

List of Tables

1.1 Comparison of resident avifauna, including endemic species in six eco- regions on the Sunda continental shelf. Data sources for resident species and endemicity are King et al. (1975), Medway and Wells (1976), Dickinson et al. (1991), Lekagul and Round (1991), MacKinnon and Phillipps (1993), Smythies (1999) and Kennedy et al. (2000).

Page

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1.2 Thirty nine endemic species that are recorded, only can be found in 6 Borneo. Of those endemic avifauna species, 26 are montane or hill-slopes

specialists (Smythies, 1999).

2.1 Primers used to amplify a partial part of mtDNA control region of 53 mountain blackeye. L and H refer to the light and heavy strand, respectively.

3.1 One-way ANOVA comparing morphological characters of the three 69 geographically isolated populations of live samples

3.2 ANOVA comparing morphological characters between Mount Murud and 70 Mount Mulu

3.3 ANOVA pairwise comparison comparing morphological characters 71 between Mount Kinabalu and Mount Mulu

3.4 ANOVA pairwise comparison comparing morphological characters 72 between Mount Kinabalu and Mount Murud

3.5 One-way ANOVA comparing morphological characters of three 73

geographically isolated populations of museum samples

3.6 ANOVA pairwise comparison comparing morphological characters 74

between Mount Kinabalu and Mount Trus Madi

3.7 ANOVA pairwise comparison comparing morphological characters 75 between Mount Kinabalu and Pueh Range

3.8 ANOVA pairwise comparison comparing morphological characters 76 between Mount Trus Madi and Pueh Range

3.9 Variable (polymorphic) positions for the partial CR of 30 individuals. Full 83

points indicate identical nucleotides to sample A4244.

3.10 Summary of standard diversity indices within the Mount Kinabalu, 84 Mount Mulu and Mount Murud populations.

xvii

3.11 Mean of pairwise distances (numbers in brackets are in percentage) 84 between Mount Mulu, Mount Mulu and Mount Kinabalu populations. The distances were corrected using a Kimura 2-parameter (K2P) model. Detailed pairwise distances between sequences can be referred in Appendix H.

3.12 Summary of mtDNA CR haplotypes distribution of mountain blackeyes in 88 Mount Kinabalu, Mount Mulu and Mount Murud populations. M represents number of individuals for each haplotype, while N represents the total number of individuals within each population. Hd indicates within-population haplotype diversity. Pi (it) indicates nucleotide diversity.

3.13 Matrix of nucleotide diversity, (above diagonal) and nucleotide 90 divergence, DXy (below diagonal) between populations.

3.14 Analysis of the molecular variance (AMOVA), grouping the three 90 populations of mountain blackeyes in a single group

3.15 Matrix of genetic variation acknowledged by Ft corrected by Kimura 2- 90 parameter model among populations of mountain blackeyes

xviii

List of Figures

Page

1.1 Location of the endemic bird areas in the Southeast Asia (Source: Long et 4 al., 1996; Taylor et al., 1999).

1.2 Map of mountain regions in Borneo. The main feature of the Bornean 5 landscape is the Bornean `spinal' chain, which runs downward from the Sabah northeast axis to the southwest. The main chain is extended off by long limb of spurs. (Source: MacKinnon and Phillipps, 1993; MacKinnon et al., 1996)

1.3 Borneo is divided into three different countries. The biggest is the 9 Indonesian territory of Kalimantan which is divided into four separate administrations. The second biggest is the East Malaysia which consists of Sabah and Sarawak. Negeri Brunei Darusalam is the smallest country within this island.

1.4 Map showing the main mountain ranges and major peaks in Borneo. 15 Elevation is in metres above sea level. (Source: MacKinnon and Phillips, 1993; MacKinnon et al., 1996)

1.5 Mountain blackeye (Chlorocharis emiliae emiliae) on Mount Kinabalu. The 31 distinct feature of this little bird is the black ring around its eye.

1.6 Distribution of mountain blackeye in Borneo. The distribution of this 32 species can be divided into western (Mount Niut and Mount Pueh) and northern region (Mount Kinabalu, Mount Trus Madi, Mount Muruk Miau, Mount Murud, Mount Mulu and Tama Abo Range). Both regions are separated by extensive lowlands and mountain areas.

2.1 Selected sampling sites for this study. 37

2.2 The vegetation at Tumau Hill, Mount Mulu. The red flowers are 41 Rhododendron species. The stunted trees are covered with lichens and moss.

2.3 Amplified mtDNA control region (CR) of mountain blackeye. Boxes in light 55 grey represent conserved domain (CD). While boxes in dark grey colour represent Third Domain (CR II). CR I is the First Domain of the mtDNA control region. The CSB-1 and the F, D and C boxes of mountain blackeye's CR correspond to the sequences from the chicken (Desjardins and Morais, 1990) and lesser snow goose (Quinn and Wilson, 1993). Glu (tRNA glutamine) and Phe (tRNA phenylalanine) are flanked at each end of the CR sequence, respectively. Primers ("' ) are referred in Table 2.1. Complete sequence of amplified mtDNA CR of mountain blackeye is presented in Appendix B.

xix

3.1 Scatterplot of root 1 versus root 2 of geographically isolated populations of 80 live samples. A detailed data can be referred in Appendix D.

3.2 Scatterplot of root 1 versus root 2 of geographically isolated populations of 80

museum samples. A detail data can be referred in Appendix D.

3.3 A strict consensus tree of 30 individuals of mountain blackeye 86 (Chlorocharis emiliae) from Mount Kinabalu, Mount Mulu and Mount Murud populations. Bootstrap values are shown above branches. The tree was rooted using the black-capped white-eye (Zosterops atricapilla). Mt. is

referred as ̀ Mount'. Tree length is 25.

3.4 Minimum spanning tree (MST) of five mtDNA control region haplotypes in 87 mountain blackeyes from Mount Kinabalu, Mount Mulu and Mount Murud populations. Crosshatches and filled squares represent transitions (TS) and transversions (TV), respectively. Numbers in circles stand for haplotype numbers. Circle sizes are in proportion to frequencies of haplotypes given in Table 3.12. Haplotypes are coloured according to the

respective population.

3.5 A mismatch distribution. Frequency distribution of pairwise nucleotide 91

sequence differences among 30 individuals of mountain blackeyes from the three populations.

CHAPTER ONE

Introduction

1.1 Avifauna endemism in Borneo

Borneo is one of the regions in the world that is strikingly rich in flora and fauna. It has

been selected by International Union for Conservation of Nature and Natural Resources

(IUCN), as one of the Endemic Bird Areas (EBAs) in the Southeast Asia (Long et al.,

1996; Taylor et al., 1999). Besides Borneo, other EBAs are located in the Malay

Peninsula, Sumatra, Java, Bali and Palawan. The regions are located on the Sunda

continental shelf (MacKinnon and Phillipps, 1993). Long et al. (1999) explained that the

endemic bird area is an area where two or more of restricted-range of (the range is less

than 50,000 km2) avifauna species, locally breeding there. Most EBAs in the Southeast

Asia are found in mountainous areas. Moreover, some of them overlap with the lowland

areas (Wikramayanake et al., 2000).

Most of the EBAs in Borneo are on the high mountainous regions along the north-

eastern coastline and continue to the central part of the island (Figure 1.1). In addition,

there are other mountainous areas with an altitudinal range of 300 m to 3,000 m above

sea level (asl) that are chosen as endemic birds `hotspots' (Figure 1.1).

Among the four Greater Sunda Islands (Borneo, Java, Sumatra and Bali), Palawan and

the Malay Peninsula, the Borneo Island has the most endemic avian species (Table 1.1).

Moreover, it is the `house' of many endemic sub-species and based on the recent

I

ornithological collections and observations (Smythies, 1999). Over 200 endemic sub-

species were identified, and currently, there are 39 endemic avian species confined in the

island of Borneo (Smythies, 1999). From the 39 endemic species, 26 species are montane

or hill slope specialists and the rest are the lowland forest species (Table 1.2). A few of

them show great resemblances to Himalayan avifauna.

The topography of Borneo that is dominated by mountains has an effect on the

variability of avifauna within this region (MacKinnon et al., 1996; Smythies, 1999). The

inaccessible mountain regions in Borneo are geographically isolated by lowland areas or

major river basins which pass through those highland regions. Due to the geographical

isolation, the avifauna species confine in the isolated mountain areas, evolve to become

endemic species (MacKinnon et al., 1996; Wikramanayake et al., 2000). The central

mountain ranges, extended from Sabah to the borderline of Sarawak and Kalimantan

(Figure 1.2) have contributed to speciation of montane avifauna (Smythies, 1999). Most

likely, each of those montane species is subjected to morphological characters changes

due to the prolong confinement within their own isolated restricted ranges, and

subsequently some of them are attainable for full or nearly species status. Besides the

geographical isolation factor, adaptation to the environment, natural selection and

neutral process are presumably factors that cause the speciation (Grant and Grant,

1993; Grant, 1994).

2

Table 1.1: Comparison of resident avifauna, including endemic species in six eco-regions on the Sunda continental shelf. Data sources for resident species and endemicity are King et al. (1975), Medway and Wells (1976), Dickinson et al. (1991), Lekagul and Round (1991), MacKinnon and Phillipps (1993), Smythies (1999) and Kennedy et al. (2000).

Eco-regions Borneo Sumatra Java Bali Palawan Malay Peninsula

Resident bird 476 520 407 221 177 488

Endemic bird 39 (8.19%) 43(8.27%)

49(12.04%) 7 (3.17%) 17(9.60%) 2 (0.41%)

3