the ecology of a small mammal population with...

THE POPULATION ECOLOGY OF NON-VOLANT SMALL MAMMALS WITH PARTICULAR REFERENCE TO THE COMMON TREESHREW (Tupaia glis)

IN GUNUNG JERAI, KEDAH

MARK RAYAN DARMARAJ

UNIVERSITI SAINS MALAYSIA

2006



by

MARK RAYAN DARMARAJ

Thesis submitted in fulfilment of the requirements for the degree

of Master of Science

May 2006

ACKNOWLEDGEMENTS

I have worked with a great number of people whose contribution in various ways led to

the research and the making of this thesis. It is a pleasure to convey my gratitude to

them all in my humble acknowledgement. First and foremost I would like to thank God,

for giving me the grace and perseverance to pull through those lonely days and nights

spent in the jungle. My deepest appreciation goes to my mum, sister, brother, brother

in-law, my soul mate-Sylvia and friends especially Retna, Saradambal, Shariff, and

Surin, for their support and encouragement.

I would also like to record my gratitude to my supervisor, Associate Professor

Dr. Shahrul Anuar Mohd.Sah for his supervision, advice and guidance from the very

early stage of this research as well as giving me an opportunity to be exposed to a

research method such as radio-telemetry. I am indebted to him more than he knows. I

am very grateful to the Forestry Department of Kedah, especially Ranger Ramli Kamis,

for the long gruesome hours spent helping me on the field.

Thanks also to the staffs of the School of Biological Sciences, University

Science of Malaysia for their indispensable help in providing transportation and help on

the field, namely, Mr. Ganesh, Mr. Muthu and others. My special appreciation goes to

Ms. Nurul Ain who was always ready to lend a hand, be it in the field conducting

research or during the thesis writing stages. Also not forgetting Ms. Nor Zalipah and

many others who were of great help out in the field. I gratefully thank Dr. Shukor, Dr.

Dino, and Gareth for their constructive comments on my work and this thesis in the

midst of all their activity and tight schedule. Finally, I would like to thank everybody who

was important to the successful realization of my thesis, as well as expressing my

apology that I could not mention personally one by one. This research was funded by

research grant IRPA No: 08-02-05-1026 EA 001.

ii

TABLE OF CONTENTS

Page

ACKNOWLEDGEMENTS ii

TABLE OF CONTENTS iii

LIST OF TABLES vii

LIST OF FIGURES xi

LIST OF PLATES xiv

LIST OF APPENDICES xiv

ABSTRAK xv

ABSTRACT xvii

CHAPTER ONE : INTRODUCTION

1.1 General introduction and justification 1

1.2 Research objectives 4

CHAPTER TWO : LITERATURE REVIEW

2.1 Previous researches in Gunung Jerai 6

2.2 Previous researches conducted on small mammals in

highlands in Malaysia

8

2.3 Previous researches conducted on small mammals using

radio-telemetry in Malaysia

10

2.4 Previous researches carried out on the Common Treeshrew in

Malaysia

12

CHAPTER THREE : METHODOLOGY

3.1 Sampling period 14

3.2 Description of study area 14

3.2.1 Climate, topography, soils and habitat types 17

3.2.2 Location, description and selection of main research area 19

3.3 Methods 23

3.3.1 Abiotic factors 23

3.3.2 Habitat description 23

3.3.2.1 Sampling techniques 24

3.3.2.2 Data analysis 26

iii

3.3.3 Small Mammals 26



3.3.4 Radio-tracking Common Treeshrews (Tupaia glis) 36



3.3.5 Nesting behaviour 42



3.3.6 Prey abundance 43


3.3.6.2 Data analysis

45

CHAPTER FOUR : RESULTS

4.1 Abiotic factors 46

4.2 Habitat description 46

4.3 Small mammal community 48

4.3.1 Trapping success 48

4.3.2 Overall captures 54

4.3.3 Relative abundance 57

4.3.4 Diversity 57

4.3.5 Sex ratio and Age structure 59

4.3.6 Reproductive season 63

4.3.7 Population size and Density 66

4.3.8 Home range based on trapping data 74

4.4 Radio-tracking Common Treeshrews (Tupaia glis) 79

4.4.1 Description of radio-tracked individuals 79

4.4.2 Activity and Movements 81

4.4.2.1 Activity and Movement parameters 81

4.4.2.2 Movement patterns and direct observations 87

4.4.2.3 Activity profile 105

4.4.3 Home Ranges and Associated Analysis 108

4.4.3.1 Cumulative area curves 108

4.4.3.2 Comparison of home range and core area estimators

114

4.4.3.3 Overall home ranges and core areas 117

iv

4.4.3.4 Comparison of home range distribution and estimates derived from radio tracking data and trapping data

121


4.4.4.1 Dimensions of nesting sites 125

4.4.4.2 Use of sleeping sites 136

4.4.5 Social organisation 142

4.4.5.1 Home range overlap 142

4.4.5.2 Use of nests between pairs 144

4.4.5.3 Dispersal 146

4.4.6 Prey abundance and Predation 147

4.4.6.1 Prey abundance 147

4.4.6.2 Predation

151

CHAPTER FIVE : DISCUSSION

5.1 Small mammals 158

5.1.1 Trapping success 158

5.1.2 Overall captures 160

5.1.3 Relative abundance 163

5.1.4 Diversity 166

5.1.5 Sex ratio and Age structure 168

5.1.6 Reproductive season 169

5.1.7 Population size and Density 173

5.1.8 Home range 175

5.2 Common Treeshrew (Tupaia glis) 180

5.2.1 Activity and movements 180

5.2.1.1 General comparison with other studies 180

5.2.1.2 Intra-specific differences within site 185

5.2.1.3 Differences between sites 187

5.2.2 Home range 195

5.2.2.1 General comparison with other studies 195

5.2.2.2 Intra-specific differences within site 197

5.2.2.3 Differences between sites 199

5.2.2.4 Home range estimates and distribution derived from two different methods

203


5.2.4 Social organisation 212

v

5.2.4.1 Home range overlap and use of nest between pairs

212

5.2.4.2 Dispersal 219

CHAPTER SIX : CONCLUSION

6.1 Small mammals 222

6.2 Common Treeshrew (Tupaia glis) 224

6.3 Recommendations for further studies 227

BIBLIOGRAPHY

230

APPENDICES

Appendix 1.0: A list of common families and species found at Site A and B as described by Kochummen (1982).

Appendix 2.0: Descriptions of sampling sessions and statistical test

vi

LIST OF TABLES

Page

3.1 The breakdown of activities for the sampling period 15

3.2 The altitudinal zones of vegetation on Gunung Jerai 20

3.3 List of variables measured and its unit of measurement 25

4.1 Average and range of temperature and relative humidity

according to Site A and Site B

47

4.2 Results derived from 16 habitat variables for Site A and Site B

based on counts (number of individuals), means and range

according to forest strata

47

4.3 Trapping success parameters in terms of number of species,

individuals, captures, catch effort, capture rate and total

capture success according to Site A and Site B

49

4.4 Number of small mammal species and number of individuals at

Site A and Site B at Gunung Jerai Permanent Forest Reserve,

Kedah

55

4.5 Number of captures, number of individuals and percentage of

individuals recaptured according to species at Site A and Site

B

56

4.6 Expected number of species using the Rarefaction method 60

4.7 Diversity indexes (Shannon-Weiner and Evenness using

Simpson’s measure) at Site A and B

60

4.8 Sex ratio and age structure of each small mammal species

captured at both study sites

61

4.9 Statistical comparisons (Chi-square test) for sex ratios and

maturity level according to each species at Site A

62

4.10 Statistical comparisons (Chi-square test) for sex ratios and

maturity level according to each species at Site B

62

4.11 Summary of the closure test with the Goodness of fit test (χ2

test statistics, p= 0.05)

68

4.12 The results of the model selection criteria under program

CAPTURE. Models selected have a maximum value of 1.00

70

vii

4.13 Summary of the test results of the model selection procedure

under program CAPTURE. The values correspond to the level

of significance of each LRT and goodness of fit tests

71

4.14 Averaged population size according to species based on the

Model Mbh (CAPTURE) at Site A and Site B

72

4.15 Mean maximum distance moved, density estimates and the

averaged density estimates according to sampling sessions

and Site

73

4.16 Averaged population size and standard error according to

species for Site A and Site B

75

4.17 Averaged population density estimate (individuals per hectare)

and standard error according to species for Site A and Site B

75

4.18 Home range of adult individuals from each species according

to sex at Site A

76

4.19 Home range of adult individuals from each species according

to sex at Site B

76

4.20 Home range of sub-adult individuals from each species

according to sex at Site A

77

4.21 Home range of sub-adult individuals from each species

according to sex at Site B

77

4.22 Home range size (m2) of adult individuals from each species

according to sex and Site

78

4.23 Home range size (m2) of Sub-adult individuals from each

species according to sex and Site

78

4.24 Morphological measurements, duration of monitoring period

and number of locations obtained for each individual at both

sites

80

4.25 Modal (mode) time of exit and entry into nest according to sex

at Site A and Site B

82

4.26 Total active period and total distance travelled for all

individuals at Site A for seven consecutive days

84

4.27 Total active period and total distance travelled for all

individuals at Site B for seven consecutive days

85

4.28 Total length of active period according to sex at Site A and Site

B

86

viii

4.29 Mean and range of total daily distances moved by adults

according to sex at Site A and Site B

86

4.30 Mean daily rate of movement and maximum observed rate of

movement by adults according to sex at Site A and Site B

88

4.31 Summary of statistical comparisons a) between Sites and b)

between sexes for the parameters- total active period, total

daily distances moved and daily rate of movement

89

4.32 Home range and core area estimation and the mean

percentage of daily movement range for each individual at both

sites

115

4.33 Mean home range, mean core area estimation and the mean

percentage of daily movement range according to site and sex

116

4.34 Home range estimates derived from using radio-tracking data

and trapping data for MA405 and FA248 at Site A

124

4.35 Description of nests used by radio-collared T.glis at Site A 126

4.36 Description of nests used by radio-collared T.glis at Site B 128

4.37 Interior details of excavated nest from both sites 133

4.38 Number of sleeping sites according to site and sex 137

4.39 Nest use of each radio-collared individual according to number

of nights and sequence of nights spent in nest at Site A

138

4.40 Nest use of each radio-collared individual according to number

of nights and sequence of nights spent in nest at Site B

139

4.41 Percentage of nest within core area (based on 50%Harmonic

Mean) at Site A and Site B according to sex

143

4.42 Static interaction index calculated based on the amount of area

overlapped by each individual at Site A

143

4.43 Static interaction index calculated based on the amount of area

overlapped by each individual at Site B

143

4.44 Number of nest used by each pair at Site A 145

4.45 Number of nest used by each pair at Site B 145

4.46 Number of insects collected from 25 pitfall traps in a period of 4

months (December 2003 – March 2004)

according to order and habitat

149

4.47 Status of each individual at Site A at the end of the study 157

4.48 Status of each individual at Site B at the end of the study 157

ix

5.1 Total active period of six Tupaia species determined by radio-

telemetry

183

5.2 Mean distances and rate of movement by six Tupaia species

as determined by radio-telemetry

184

5.3 Mean home range size of six Tupaia species 196

5.4 Number of nests and rate of nest shift by six Tupaia species 210

x

LIST OF FIGURES

Page

1.1 A model chart that describes the study objectives 5

3.1 Location of Gunung Jerai on the Peninsular Malaysia map 16

3.2 Monthly variation of rainfall for the year 2002 and 2003 18

3.3 Map showing the two study sites 21

3.4 Study grid showing trapping points 28

4.1 Species accumulation curves for a) Site A and b) Site B 51

4.2 Number of new individuals against cumulative trap-nights at a)

Site A and b) Site B

52

4.3 Trap success and average rainfall against cumulative trap-

nights at a) Site A and b) Site B

53

4.4 Relative abundance of every species caught at Site A and Site

B

58

4.5 Rarefaction curve for Site A and Site B 58

4.6 Number of individuals caught at Site A in each month

according to two maturity levels a) Juveniles and b) Sub-adults

and also depicting average rainfall in each month c) Rainfall

64

4.7 Number of individuals caught at Site B in each month

according to two maturity levels a) Juveniles and b) Sub-adults

and also depicting average rainfall in each month c) Rainfall

65

4.8 The number of sub-adult Tupaia glis caught according to sex in

each month at a) Site A and b) Site B

67

4.9 Movements made by FA248 for seven consecutive days 91


4.11 Movements made by MA443 for seven consecutive days 93


4.13 Movements made by MA405 (Day 1) and MA 443 (Day 5)

which depicts their movement around a fruiting tree

95

4.14 Movements made by FA 248 (Day 5) and FA 499 (Day 3)

which depicts their movement around a fruiting tree

96

4.15 Movements made by MA405 (Day 4) and MA 443 (Day 6)

which depicts no clear movement around a fruiting tree

98

xi

4.16 Movements made by FA248 (Day 3) and FA 499 (Day 6) which

depicts no clear movement around a fruiting tree

99





4.21 Movements made by FS970 for seven consecutive days 104

4.22 Activity profile of a) females, b) males and c) mean

temperature and relative humidity during the specified hour of

the day at Site A

106

4.23 Activity profile of a) females, b) males and c) mean

temperature and relative humidity during the specified hour of

the day at Site B

107

4.24 Number of fixes required to reach an asymptote for females at

site A; a) FA248 and b) FA499

109

4.25 Number of fixes required to reach an asymptote for males at

site A; a) MA443 and b) MA405

110

4.26 Number of fixes required to reach an asymptote for females at

site B; a) FA973 and b) FA975

111

4.27 Number of fixes required to reach an asymptote for males at

site B; a) MA971 and b) MA905

112

4.28 Number of fixes required to reach an asymptote for sub-adult

females; a) FS915 at site A and b) FS970 at Site B

113

4.29 The distribution of the home range and core area of all

individuals (except individual FS 916) at Site A

119

4.30 The distribution of the home range and core area of all

individuals at site B

120

4.31 Graphical distribution of home range based on the 100%

Minimum Convex Polygon using trapping data at Site A

122

4.32 Graphical distribution of home range based on the 100%

Minimum Convex Polygon using radio-tracking data at Site A

122

4.33 Graphical distribution of nests within the home range

(MCP95%) of radio-collared individuals at Site A

140

4.34 Graphical distribution of nests within the home range

(MCP95%) of radio-collared individuals at Site B

141

4.35 Movements made by FS915 for three consecutive days. 148

xii

4.36 Biomass of insects collected according to each month

(December 2003- March 2004)

150

xiii

LIST OF PLATES Page

4.1 A tree crevice opening on a large tree that was about two

meters from the ground at Site A.

130

4.2 A peculiar nest at Site A made from a pile of leaves and twigs on an entanglement of vines stretched between two trees and was shaped like a rugby ball with only one opening leading into it.

131

4.3 One of the nests with two openings at the base of the root of a tree on the ground at Site B.

134

4.4 One nest was found with a cavity opening in a tree stump that was about six metres from the ground at Site B.

135

4.5 Individual MA971’s head torn apart from its body in the cage trap with only its head left in the trap without the collar.

152

4.6 MA971’s radio-collar was later found under the leaf litter near the trap location

153

4.7 Close-up of the hind feet of the injured FA973.

154

4.8 The injured FA973 that was found dead two hours after release.

155

LIST OF APPENDICES

1.0 Appendix 1.0: A list of common families and species found at Site A and B as described by Kochummen (1982).

2.0 Appendix 2.0 : Descriptions of sampling sessions and statistical test

xiv

EKOLOGI POPULASI MAMALIA KECIL NON-VOLAN DENGAN TUMPUAN UTAMA KEPADA TUPAI MUNCUNG BESAR (Tupaia glis) DI GUNUNG

JERAI, KEDAH

ABSTRAK

Satu kajian dua fasa ke atas mamalia kecil dengan tumpuan utama kepada Tupai

Muncung Besar (Tupaia glis) telah dijalankan di dua zon vegetasi yang berbeza (tapak

kajian A; Hutan Dipterokarp Bukit dan tapak kajian B; Hutan Pergunungan Myrtaceous)

di Gunung Jerai, sebuah gunung terpencil di Kedah. Fasa satu dijalankan dengan

mengunakan Kaedah Tangkap-Tanda-Lepas pada setiap bulan dengan menggunakan

100 perangkap dawai yang dijarakkan 10m, di dalam grid seluas 0.81ha di setiap

kawasan tapak kajian. Persampelan dijalankan dari bulan Oktober 2002 sehingga

bulan Jun 2003. Sejumlah 10 spesis mamalia telah dicerap di kedua-dua tapak kajian.

Kejayaan penangkapan di tapak kajian A dan B adalah 6.00% dan 6.81% masing-

masing. Tupaia glis dan Maxomys rajah mendominasi tapak kajian A, manakala di

tapak kajian B pula adalah T. glis dan M. whiteheadi. Kawasan tapak kajian B

menampung komposisi mamalia kecil yang lebih kaya dan berkepelbagaian

dibandingkan dengan kawasan tapak kajian A, dan ini disebabkan oleh kejadian

pertindihan spesis yang ketara di kawasan tapak kajian B. Pengagihan individu antara

spesies adalah lebih seragam di kawasan tapak kajian A dibandingkan dengan tapak

kajian B dan ini kemungkinan disebabkan oleh peningkatan keterdapatan mikrohabitat

dan sumber makanan di kawasan tapak kajian A. Bagi Tupaia glis pembiakan berlaku

sepanjang tahun terutamanya antara April dan Ogos dengan tiada perbezaan tempoh

antara kedua-dua tapak kajian. Kepadatan T. glis di kedua-dua tapak kajian didapati

hampir sama (4±1/ha di A dan 5±1/ha di B). Fasa dua dijalankan dengan

menggunakan kaedah radio-telemetri ke atas lima individu T. glis dari Disember 2003

sehingga Mac 2004. Di setiap tapak kajian, corak aktiviti adalah bimodal. Jumlah

tempoh masa keaktifan harian, jumlah jarak yang dilalui setiap hari dan jumlah kadar

pergerakan harian bagi individu dewasa di B didapati lebih panjang dan lama secara

xv

signifikan jika dibandingkan dengan individu di A (Ujian-Mann-Whitney U-Test).

Individu dewasa di tapak kajian B mempunyai saiz kawasan kediaman dan saiz

kewasan kediaman pusat yang lebih besar secara signifikan jika dibandingkan dengan

di A (Mann-Whitney U-Test). Kualiti habitat dari segi keterdapatan sumber makanan

yang berubah mengikut altitud berkemungkinan besar merupakan sebab utama bagi

perbezaan tersebut. Secara keseluruhannya, saiz kawasan kediaman adalah 0.80–

1.18ha (MCP95%) manakala kawasan kediaman pusat adalah 0.34- 0.57ha (HM50%).

Di A, hampir 88% daripada jumlah sarang didapati berada dalam pokok tumbang dan

lubang pokok sementara di tapak kajian B, hampir 89% daripada sarang didapati

berada di dalam lubang yang digali di kaki akar pokok. Individu-individu di kedua-dua

tapak kajian didapati bersarang di kawasan kediaman pusat. Indeks interaksi statik

menunjukkan organisasi sosial monogami bagi kedua-dua populasi T. glis.

xvi



ABSTRACT

A two-phase study on small mammals with particular reference to the Common

Treeshrew (Tupaia glis), was conducted at two different floristic zones (Site A;

Hill/Upper Dipterocarp Forest and Site B; Montane Myrtaceous Forest) on Gunung

Jerai, an isolated mountain in Kedah. Phase one consisted of a monthly Mark-

Recapture study using 100 cage wire traps, spaced 10m apart in a 0.81ha trapping grid

on each site. Trapping was carried out from October 2002 till June 2003. A total of 10

species of small mammals were recorded at both sites. Capture success at Site A and

B were 6.00% and 6.81% respectively. Tupaia glis and Maxomys rajah were the two

dominant species at Site A, whilst at Site B these were, T. glis and M. whiteheadi. Site

B proved to be more rich and diverse in small mammal composition than Site A due to

the considerable degree of species overlap taking place at Site B. Distribution of

individuals among species was more even at Site A compared to Site B probably due

to increased microhabitat and food resource availability at Site A. For T. glis, breeding

occurred throughout the year with a peak between April and August, without any

marked differences between both sites. Density for T. glis at both sites were similar

(4±1/ha at Site A and 5±1/ha at Site B). Phase two of this study consisted of a radio-

telemetry study on T. glis which was carried out from December 2003 till March 2004.

Five individuals were radio-collared at each site. Individuals at both sites conformed to

a bimodal activity pattern. Total length of daily active periods, total daily distances

moved and daily rate of movements by adult individuals at Site B were found to be

significantly longer and higher compared to individuals at Site A (Mann-Whitney U-

Test). Adult individuals at Site B had significantly larger home range size and core area

size than individuals at Site A (Mann-Whitney U-Test). Habitat quality in terms of food

xvii

availability, which varied altitudinally is highly likely the prime influential factor for these

differences. Overall home range sizes were 0.80-1.18ha (MCP95%), whilst core areas

were 0.34-0.57ha (HM50%). At Site A, almost 88% of nests were found to be in fallen

logs and tree holes whilst, at Site B, almost 89% of nests were found in dug burrows at

the base of the roots of trees. Individuals at both sites were found to preferentially nest

in core areas. The static interaction index revealed a monogamous social organisation

for both populations of T. glis.

xviii

CHAPTER 1 INTRODUCTION

1.1 General introduction and justification

Malaysia is endowed with a great diversity of fauna species in its forests. These

forests are able to support such a rich diversity of wildlife due to the adaptations of

each species to utilise different spatial and temporal niches within the forest mosaic. In

Malaysia, a total area of 1.39 million hectares are gazetted as national parks, protected

areas and wildlife sanctuaries but the majority of these consist of scattered fragments,

isolated amidst matrices of agricultural and developmental areas (Anon., 1998).

Habitat fragmentation is a major threat to wildlife population, particularly for

area demanding species such as mammals and since the 1960’s, Malaysia has

experienced considerable forest loss (Laidlaw, 2000). Several studies have

investigated the impacts of forest conversions and logging activities on wildlife, and

changes in forest structure due to logging have been related to local extinction of

mammal species, while others do well in logged forests (Johns, 1992; Johns, 1997;

Fimbel et al., 2000). With this in mind, it should be stressed that it is essential to gain a

basic understanding of primary ecosystems and the role of the various communities of

plant and animal species in an undisturbed habitat. However, research on species

composition and distribution of various animals in different types of habitats or floristic

zones is still in its infancy in Malaysia.

Malaysia has a particularly diverse small mammal fauna. Small mammals play

an important role in forest ecosystems serving several important functions, such as

seed dispersal, preying on insect pests and also as being a prey itself to predators

(Brisbal, 1986; Miura et al., 1997; Zubaid & Khairul, 1997; Ray, 1998; Shanahan &

Compton, 2000). Several species are threatened and endangered (Ratnam et al.,

1991). Because experimental studies or even observational studies are not possible on

endangered, large or rare species, ecological model species or systems are sometimes

1

used to test predictions of how a species will respond to some perturbation (Wolff,

1999). But before we can formulate an ecological model species or system, detailed

information regarding the biology and natural history of a certain species and its

community is vital.

Information about population size, reproduction, diet, home range, social

organization and nesting behaviour are among the basic vital information, which is

needed to understand a certain species before any effort in trying to conserve them

and their habitats are to be enforced. Understanding the spatial distribution and

movements that a certain species makes within its habitat is important for interpreting

ecological processes and plays a vital role in formulating conservational management

plans.

The primary objective for this small mammal study was to increase the

information available on tropical small mammals with particular reference to the

Common Treeshrew (Tupaia glis) at two different elevations. Many studies have shown

that changes in physical characteristics over a short distance along an elevational

gradient would affect the species diversity, distribution and abundance of organisms

(Kano, 1940; Terborgh, 1977; Kitayama, 1992; Yu, 1994; Zainab et al., 2001). Altitude

determines either the presence or the absence of certain plants and the abundance of

fauna. There have been very few long term studies on comparing diversity and other

aspects of the ecology of Malaysian small mammals in different habitat zonations or

elevations. The very few studies done have contributed to the understanding of small

mammal species composition along an elevational gradient (Shukor, 2001; Zainab et

al., 2001) but no long term studies have been done on isolated mountains such as

Gunung Jerai in Peninsular Malaysia. Although this study did not concentrate on an

elevational gradient throughout a mountain but rather in two distinct floristic zones,

each occurring at different elevations, this study does offer an important contribution to

the understanding of species composition and ecology of small mammals on an

isolated mountain.

2

For most of the past century, scientists thought that treeshrews were primitive

primates. Systematics has played an important role in differentiating animals based on

certain characteristics. According to Emmons (2000), treeshrews suffer from a chronic

case of mistaken identity for they are not shrews and most are not found in trees.

Earlier studies involving taxonomy, morphology, reproduction and social behaviour of

treeshrews have considered only a single species, T. glis and there has been a

tendency to regard this species as “the” treeshrew and consider findings as

characteristic of the family Tupaiidae. But studies made of other species have shown

that there are marked behavioural differences between species (Sorenson & Conoway,

1968). Although, there have been quite a number of anatomical, embryological and

behavioural studies carried out on captive treeshrews (Sorensen & Conoway, 1968;

Sorenson, 1970), only two detailed field ecology studies (Kawamichi & Kawamichi,

1979; Langham, 1982) have been done on the Common Treeshrew in the wild in

Malaysia. As a result, there is still very little known about the Common Treeshrew

although its name itself suggests that it is ‘common’. Thus, this study represents a key

contribution to the understanding of the ecology of the Common Treeshrew in its

natural habitat.

On the whole, the primary contribution that this study offers is that methods and

results interpretation about the Common Treeshrew and its community could be used

as a model to study other small mammal species or even other bigger mammals with

mathematical and statistical modifications. In addition, this study provides future

researchers and conservation managers with information on spatial and population

dynamics of small mammals that inhabit different floristic zones, especially on an

isolated mountain.

3

1.2 Research objectives

The objective of this study was to obtain information on the small mammal

community with particular reference to the Common Treeshrew that inhabit two

different floristic zones on an isolated mountain (Figure 1.1). Thus, the research

objectives can be divided into two main parts as mentioned below:

a) To investigate the ecology of terrestrial small mammals at two different floristic

zones with specific emphasis on determining the following:

1) To identify and compare species composition and abundance

2) To investigate the probable reproductive season according to species using

trapping data

3) To estimate population size and density according to species

4) To estimate the home range of small mammals according to species using

trapping data

b) To investigate the ecology of Tupaia glis at two different floristic zones with

specific emphasis on determining the following:

1) Activity and movements

2) To estimate the home range using radio-tracking data and also to compare

estimates derived from trapping data

3) Nesting behaviour

4) Social organisation

4

Gunung Jerai (Isolated Mountain)

Vegetation Abiotic factors

Habitat

Lowland Forest

Montane Forest

Small mammals • Composition and abundance • Reproductive season • Population and density • Home range

Comparison

Common Treeshrew (Tupaia glis)

Activity and movements Home range Nesting behaviour Social organisation

Figure 1.1: A model chart that describes the study objectives.

5

CHAPTER 2 LITERATURE REVIEW

2.1 Previous researches in Gunung Jerai

The botanists were probably the first professional biologists to explore Gunung

Jerai since colonial times. Research on flora in Gunung Jerai started in the late 19th

century. Most of the botanist collected specimens for the purpose of adding to their

herbarium collection. Thomas Lobb was the first among researchers who collected

horticultural materials for the Kew Herbarium in London (Ridley, 1916). Although

Gunung Jerai is located very close to southern Thailand, the flora in Gunung Jerai has

been noted to inherit the characteristics of Malaysian flora.

According to Ridley (1916), the vegetation in Gunung Jerai is identical to that

found in Gunung Ledang, Johor, based on the assumption that both these mountains

used to be islands that were isolated from the mainland. Apart from Ridley, Mohamed

Hanif of the Singapore Botanic Gardens also collected plants from Gunung Jerai in

1915. Robinson & Kloss (1916) reported that more than 200 flowering plants species

(mainly orchids) were found at an altitude of above 800m above sea level. Between the

1920s and 1940s, massive specimen collection was conducted in Gunung Jerai, for

collection purposes in the Singapore Botanical Gardens.

Marchette (1965) discovered a new species of ‘Monkeys Cup’ Nepenthes

albomarginate on this mountain. He also added new plant species to the list of higher

plants in the gymnosperm and angiosperm groups. Dunn (1967) added 18 species of

ferns which accumulated to a total number 78 fern species or rather 16% of the ferns

that was listed in Malaysia during that time. Kochummen (1982) demarcated the

difference in vegetation according to altitudinal gradient in Gunung Jerai. His findings

stirred great interest among other botanists as he reported that the Oak Laurel forest

that were found in other highlands in Malaysia was absent in Gunung Jerai.

6

Kochummen (1982) classified this floristic zone as ‘Myrtaceous’, as it was dominated

by this Genus at an elevation of above 780m above sea level.

Research on fauna in Gunung Jerai began as early as 1915 by Robinson &

Kloss (1916). They listed 10 species of small mammals, 36 species of birds and 13

species of herpetofauna in the area. Researches on insects have also been carried out

on this mountain. Hislop (1949) described the differences in butterflies from the Genus

Milium that was found here and in two other mountains in Malaysia (Gunung Ledang

and Gunung Padang). Domrow & Nadchatram (1963) found that most of the small

mammals in Gunung Jerai had ecto-parasites, belonging to the Family Mesostigmata

and Prostigmata.

Yong (1969) recorded three species of small mammals; two of which were new

records for Gunung Jerai at that time. These new species were Sundamys muelleri and

Niviventer sp. A total of 11 species of small mammals in Gunung Jerai were recorded

by Langham (1983). Gregory-Smith (1994) recorded 67 species of birds in Gunung

Jerai. He found that due to the absence of ‘true’ montane bird species, lowland bird

species had dispersed to higher altitudes.

A freshwater crab species (Phricotelphusa amnicola) which is believed to be the

third record for Peninsular Malaysia from the family Gecarcinucidae was found in the

waterfalls of Gunung Jerai at an altitude of 800m above sea level (Ng, 1994). A recent

study conducted on the distribution of understorey bats along an elevational gradient,

recorded a total capture of 317 individuals from 18 species comprising of four Families

(Rhinolophidae, Hipposideridae, Vespertilionidae and Pteropodidae) (Shahrul et al.,

2003). They found a decrease in number of bat species with increasing elevation and

inferred that it was most likely due to the unfavourable climatic condition at higher

elevations. It is important to note that the literature mentioned in this sub-chapter is

taken only from published journals and does not include researches that would have

been conducted for the purpose of thesis writing.

7

2.2 Previous researches conducted on small mammals in highlands in

Malaysia

There has not been many researches conducted on small mammals in

highlands in Malaysia mainly due to the consequences of sampling in difficult terrain in

a tropical environment. The few studies that have been carried out (Medway, 1972;

Lim, 1974; Langham, 1983; Shukor, 1997; Zainab, 2001) although not all, have been

extensive rather than intensive in which sampling was conducted during a limited

period of time (not representative of all climatic seasons). Nevertheless, such studies

mentioned above are important in producing predictions as to how non-volant small

mammal species richness and abundance change with increasing altitude within

various floristic zones.

Apart from the studies mentioned above, there are other short-termed studies

that have been conducted in highlands such as Robinson & Kloss (1916), Domrow &

Nadchatram (1963) and Yong (1969; 1974) but these researches offered only

anecdotal evidence about diversity and abundance of small mammals that inhibited

different floristic zones across an elevational gradient. Among all the studies mentioned

above, only Shukor (1997) and Zainab (2001) extensively focused their study on

distribution and diversity of small mammals across an elevational gradient within five

(lowland, lower montane, upper montane, sub-alpine) and four (lowland, hill

dipterocarp, submontane and montane) different floristic zones. Shukor (1997)

concentrated more on explaining the elevational diversity pattern of small mammals

that inhibited Mount Kinabalu. His study produced evidence of a hump shaped diversity

pattern occurring across an elevational gradient.

He reported that the maximum diversity of small mammals occurred at the

elevation where a highland and a lowland assemblage overlapped of which several

types of plants reached their maximum diversity and within this transition zone, rainfall

and humidity was also recorded to reach their maxima. Although his study proved to be

8

invaluable in predicting elevational diversity patterns of small mammals in highlands,

the population dynamics and demographic details of small mammals inhibiting the

different floristic zones on Mount Kinabalu, have yet to be documented. On the whole,

various aspects such as population size, home range and reproductive strategies (e.g.

reproductive seasons) pertaining to heterospecific populations of small mammals in

differing floristic zones across an elevational gradient have yet to be documented in

Malaysia.

Although Zainab (2001) did not look into the aspect of reproductive strategies of

small mammals at different elevations, she did manage to estimate home range size of

at least one species (Leopoldamys sabanus) in five different elevations with the use of

live traps. She found that the home range of this species seem to increase as elevation

increased but only from lowland (300m a. s .l.) till sub-montane forest (1100m a. s. l.)

after which home range size was smaller on montane forest (1350m a. s. l.). She

deduced that the differences in home range size across different floristic zones was

mainly influenced by the density of individuals of which supported the hypothesis of

inverse correlation of home range size and density.

In summary, most small mammal studies on highlands in Malaysia, as

mentioned above, have solely restricted their research on either figuring out diversity

patterns across elevational gradients or investigating demographic patterns of small

mammals (particularly abundance) with relatively low sampling effort within certain

arbitrarily chosen elevations. Functional relationships of small mammals may vary

according to habitat. Having acknowledged this in the context of investigating small

mammal ecology across an elevational gradient, this study aims to gain information on

population demographics of small mammals on two distinct floristic zones. It is hoped

that a better understanding of the complexity of small mammal dynamics in two

differing habitats associated with differing vegetation (both in structure and

composition) will be attained.

9

2.3 Previous researches conducted on small mammals using radio-

telemetry in Malaysia

Gaining information on the ecology of small mammals with the use of radio-

telemetry is still in its infancy in Malaysia as indicated by the very few citations

mentioned in this sub-chapter although interestingly the first ever radio-tracking study

in this region was conducted four decades ago. Since then, only two other detailed

radio-telemetric studies have been conducted on small mammals in Malaysia. Thus

this study although focusing on a single species, is probably the fourth detailed radio-

telemetric study conducted on small mammals in Malaysia.

Sanderson & Sanderson (1964) used modified miniature transistorized radio

transmitters that weighed about 16-32g which were rather heavy compared to the units

that were used in my study that weighed 4.5g. They radio-tracked nine rats from the

species Sundamys mulleri, Leopoldamys sabanus and Rattus tiomanicus for a period

of one to sixteen days in the Ulu Gombak area of Selangor. They noted there was

overlapping of home ranges of rats of the same species and of different species.

Apart from that, they also mentioned that with some exceptions, most of the

radio-tracked rats returned to the same nests each day. Although important information

on spatial ecology of some rats were discovered, the authors (Sanderson &

Sanderson, 1964) described their findings in a rather descriptive manner with hourly or

daily accounts of individual movement. Nevertheless, it is important to note that

observations such as the ones mentioned above, would not be possible if radio-

telemetry had not been used.

A field study on Bornean treeshrews with the use of radio-telemetry was

conducted between 1989-1991 in Sabah. This study (Emmons, 2000) was actually the

first ever detailed radio-telemetry field research carried out on six species of

treeshrews (Ptilocerus lowii, Tupaia minor, T. gracilis, T. montana, T. tana and T.

longipes). Emmons (2000), describes in detail the diet, nesting behaviour, home range,

10

activity pattern and social organisation of the six treeshrew species mentioned above.

Furthermore, she also successfully managed to observe the absentee maternal care in

the wild, of which previously was only observed in captive studies. She stresses that

none of the above mentioned ecological observations particularly the lack of maternal

care in T. tana would have been possible without the use of radio-telemetry. Generally,

one of the important conclusions that she made was that each treeshrew species

differing lifestyles could be explained or attributed to their differences in foraging sites

and prey. Although Emmons (2000) covered various aspects of ecological differences

that exist within six treeshrew species, the Common Treeshrew T. glis which is also

present in Sabah, was not included in her study. In fact, Emmons (2000) noted that

there has not been any detailed study on the nesting behaviour of the Common

Treeshrew in Malaysia. Thus, this study which aims to gain information on the nesting

behaviour of the Common Treeshrew may well be the first to document this aspect in

detail.

Although the third published radio-telemetry small mammal study in Malaysia

was carried out in 1992-1993, surprisingly, it was only published eight years later.

Saiful et al. (2001), investigated the home range sizes and spatial overlap of four

sympatric species of squirrels (Callosciurus caniceps, C. notatus, C. nigrovittatus and

Lariscus insignis) in a lowland Dipterocarp forest in Ulu Gombak, Selangor. The radio-

transmitter collars that were used by Saiful et al. (2001) weighed about 6-7g. They

found that generally, home range size did not differ seasonally. However, they did note

that home range overlap among intraspecific individuals was common but differed

among species mainly because of the differing space use of the vertical strata of the

forest.

On the whole, all three radio-telemetry studies mentioned above, generally

found radio-tracking small mammals to be difficult in Malaysia due to the soil, terrain

and dense foliage which evidently caused interference to radio signals. Finally, it is

worthy to note, that only researches that have been published in journals are cited in

11

this sub-chapter. Although there might have been radio-telemetry studies conducted on

small mammals in Malaysia purely for the purpose of fulfilling the requirements of a

degree through a dissertation, these were not included in this sub-chapter due to the

probable nature of findings that were perhaps inadequate to be published in journals.

2.4 Previous researches carried out on the Common Treeshrew (Tupaia

glis) in Malaysia

There are only two detailed field studies (Kawamichi & Kawamichi, 1979;

Langham, 1982) carried out in the wild on the Common Treeshrew (Tupaia glis).

Another researcher, Lim Boo Liat also carried out field observations on the social

behaviour of paired T. glis (Lim, 1995a) but these were very subjective in nature as

acknowledged by himself in his paper. Apart from this, removal studies through

trapping (Lim, 1995b; 1998) were also carried out to gain information on the food habits

and reproductive pattern of T. glis. Despite having four field studies (inclusive of Lim,

1995a; 1995b) that have been carried out on T. glis, certain aspects of its natural life

history such as activity pattern, movement pattern and nesting behaviour have yet to

be documented. A brief summary of the nature of each previous research mentioned

above are given in the next paragraphs.

Langham (1982) carried out a three year (1972-1975) study on T. glis through

live trapping in the states of Penang and Kedah. He collected comprehensive data on

space use in terms of vertical stratification, reproduction, density, survivorship, mortality

and diet. Although Kawamichi & Kawamichi (1979) published their findings earlier than

Langham (1982), their field research was carried out from end of September 1974 till

end of March 1975.

Technically their (Kawamichi & Kawamichi, 1979) research should not be

included in this sub-chapter because their research was actually carried out in

Singapore. However, their research is a significant contribution towards understanding

12

the spatial organisation of T. glis and due to the fact that the geographical difference

does not vary very much (difference only in terms of classification of sub-species), their

research needs to be mentioned here. Kawamichi & Kawamichi (1979) carried out

direct observations on 117 T. glis that indicated that they were more terrestrial than

arboreal. They reported that the social organisation of T. glis was mainly monogamous

of which a solitary ranging pair occupied an area of less than 1ha. Findings from the

same study related to the timing of independence of offspring were later published in

another journal (Kawamichi & Kawamichi, 1982). They inferred that juveniles of

different sex dispersed according to the reproductive status of their mothers.

Lim (1995a) also noted from direct observations that T. glis were mainly

terrestrial. Interestingly, Lim (1995a) managed to observe the copulation of a pair of T.

glis in his study. Lim (1995b) examined 85 stomach contents of T. glis and concluded

that insects were their prime diet (just as Langham (1982) had inferred). Lim (1998)

concluded that T. glis were found to breed all year round but with a peak from March to

June similar to the findings of Langham (1982).

Although the researches mentioned above have contributed towards a better

understanding of T. glis in the wild and proved to be invaluable, however it is evident

that to some extent the methods that were used (trapping and direct observations) in

their research precluded them to gain other sorts of information. Certain aspects on the

ecology of T. glis such as activity pattern and nesting behaviour can only be revealed

by means of radio telemetry or other tracking methods and it has to be stressed here

that the use of such a method has never been carried out on this particular species in

the wild. Thus, the current research in this study may well constitute the first radio-

telemetry study to shed some light into the ecology of T. glis.

13

CHAPTER 3 METHODOLOGY

3.1 Sampling period

This study was carried out in two phases. The first phase was to carry out a

monthly Mark-Recapture study on small mammals which was done from the month of

October 2002 till June 2003 (Phase 1). The second phase was to carry out a radio-

telemetry study on the Common Treeshrew (Tupaia glis) which was done from the

month of December 2003 till March 2004 (Phase 2). The breakdown of activities of the

two phases are better reflected in Table 3.1.

3.2 Description of study area

This study was conducted in Gunung Jerai Permanent Forest Reserve, Kedah.

Gunung Jerai, which was formerly known as Kedah Peak, is an isolated mountain in the

state of Kedah (Figure 3.1). This isolated mountain lies at a latitude of 5°47’N and a

longitude of 100°26’E and rises to an altitude of 1217m above sea level (a.s.l.). The

general structure of Gunung Jerai has been described as a hill composed mainly of

sandstone and quartzite, with a core of granite (according to Kochummen, 1982 referring

to Bradford, 1972).

Gunung Jerai is a forest reserve managed by the Kedah Forestry Department.

Some parts (mainly on the western part) of the mountain have been previously

selectively logged. Other parts of the mountain (mainly below an elevation of 300m

a.s.l.) have been cleared for rubber plantations and fruit orchards. There is one main

road leading up to the mountain’s telecommunication station and resort.

14

Table 3.1: The breakdown of activities for the sampling period.

Year 2002 2003 2004 Month Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Phase

Activiti es Identifying main

study area & setting up the

study grid

Phase 1 Small mammal

monthly Mark-Recapture

study at both sites

simultaneously

Pilot study for radio-telemetry on the field and

habitat assessments

Phase 2 Sampling

Period for radio-tracking study & prey abundance sampling

15

Figure 3.1: Location of Gunung Jerai on the Peninsular Malaysia map. Note: This map is not to scale.

16

3.2.1 Climate, topography, soils and habitat types

The average rainfall for the ten year period of 1965-1975 was 357cm/year and

the wettest months are May to October and driest is February (Kochummen, 1982).

Rainfall data provided by the Muda Agricultural Development Authority (MADA), for the

nine year period of 1994-2002, averaged about 309cm/year. The monthly variation of

rainfall for the year 2002 and 2003 is given in Figure 3.2.

In terms of topography, Gunung Jerai is an isolated massif forming a single peak

that sweeps down on all sides into flat lowlands. Escarpments with steep to vertical

drops of considerable extent are frequent on the western, south-western and north-

western sides (Anon., 1977). The slopes are generally steep; the steeper slopes to the

north and west are of hard quartzite, while the more gentle southern slopes are

underlain by granite or schist (Kochummen, 1982).

Gunung Jerai has been isolated for a geologically lengthy period and in the past

has been an island. The geological structure of the mountain and its present flora seem

to attest to the fact that it was an island before. The massif is largely granite and

sandstone, and in many places the bedrock is exposed as flat expanses of rock or as

large boulders. The soil compositions at different elevations, especially at different

floristic zones are distinctively unique. Above an elevation of 750m a.s.l., the sandy

nature of much of the soil has in several areas resulted in the production of heath forest.

The soil under this forest is nutritionally poor, patchily covered with peatmoss

(Sphagnum sp.), typified by a slow decay rate of organic matter and retention of an

acidic milieu (Kochummen, 1982). Below an elevation of 750m a.s.l., the soil is much

richer, resulting in the production of a taller and more diverse forest.

In terms of habitat types, there appears to be few quantitative studies on the

changes of vegetation in Peninsular Malaysia (Kochummen, 1982), except for previous

work on the classification of forest types with respect to altitude (Symington, 1943;

17

0200400600800

10001200140016001800

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Months

Rain

fall

(cm

)

2002 2003

Figure 3.2: Monthly variation of rainfall for the year 2002 and 2003.

18

Burgess, 1969; Whitmore, 1985). Because of its isolation, Gunung Jerai has the

“telescoped” zonation by altitude similar to islands and isolated peaks; the montane oak

forest vegetation type, common on hills of the main range between an elevation of

1000m and 1500m is absent here, instead the myrtacecous forest and ericaceous forest

is obvious at these elevations (Kochummen, 1982). The lower and upper Dipterocarp

forest types seem to be merged between the elevations of 480m and 750m above sea

level. The altitudinal zones of vegetation in Gunung Jerai as summarised by

Kochummen (1982), is given in Table 3.2.

3.2.2 Location, description and selection of main research area

Two study sites were chosen to fulfil the study objectives. Site A (500m a.s.l.)

and Site B (900m a.s.l.) were chosen mainly because both sites fall on two different

floristic zones described by Kochummen (1982) which are Hill/Upper Dipterocarp Forest

(merged) and Montane Myrtaceous Forest respectively. For logistic reasons and also to

avoid disturbance, both sites chosen, were at least 200 meters away from the road that

lead to the chalet (Figure 3.3). For the purpose of this study, a site is defined as the

general area chosen to locate a trapping grid. Trapping grid parameters for both sites

are described in sub-chapter 3.3.3.1.

At first sight, the structure of the forest at Site A (ranged from 500 – 520 m a.s.l.)

is like any lowland forest type with emergent trees reaching to heights of 60 to 80 m. But

according to Kochummen (1982), the vegetation at this elevation (500m), is a mix of Hill

Dipterocarp Forest and Upper Dipterocarp Forest. Site A is mainly dominated by trees

from the family Dipterocarpaceae, such as Shorea curtisii and Shorea ovata. At mid-

storey level, Eugeissonia tristis or commonly referred to as ‘Bertam”, a common

understorey palm, is abundant at this site. Because this site has huge canopy hovering

trees and abundance of palm trees, there is not much light penetrating the forest floor,

hence

19

Table 3.2: The altitudinal zones of vegetation on Gunung Jerai (Kochummen, 1983)

Floristic Zones Elevation above sea level (meters)

Lowland Dipterocarp Forest 150 – 210

Hill / Upper Dipterocarp Forest (merged) 480 – 750

Montane Myrtaceous Forest 780 – 1140

Montane Ericaceous Forest 1200

20

Figure 3.3: Map showing the two study sites (Site A- 500m above sea level & Site B- 900m above sea level).

21

contributing to conditions that do not favour dense vegetation on the forest floor. Another

characteristic that is distinct to this site is the huge size and length of the fallen logs on

the forest floor.

Site B (ranged from 900–940 m a.s.l.), is classified by Kochummen (1982) as

Montane Myrtaceous Forest due to the abundance of trees from the family Myrtaceae

and also because the Oak-Laurel floristic zone is absent at this elevation. Site B is

mainly dominated by trees from the family Myrtaceae, such as Eugenia sp. and

Tetractomia tetrandra. The trees at this site do not exceed a height of 30m. Two main

characteristics distinct at this site are the abundance of leaf litter and dense mid-storey

vegetation, such as shrubs, herbs and vines.

The research areas (Site A and Site B) were selected mainly for the following

reasons:

• Other possible sites at different elevations, which constitute different

floristic zones such as 100m to 300m and above 1000m to 1217m, were

habitats that had some kind of disturbance. For example, most of the

habitats from the foothills of Gunung Jerai till an elevation of about 350m

have already been converted to fruit orchards. Thus, only two floristic

zones (Site A and B) could be used to investigate the parameters

mentioned in the study objectives.

• Other possible sites along the same elevational gradient were deemed

too steep and logistically difficult. Due to this limitation, it was not possible

to set trapping grids or rather have replicates for both sites along the

same elevations.

• Both sites were not disturbed by the general public who visited the area

mainly because both sites were chosen to have a buffer distance of at

22

least 200 meters from the road. Apart from that, there were no existing

nature trails that lead to both study sites.

3.3 Methods

3.3.1 Abiotic factors

Abiotic factors include edaphic, all aspects of climate, geology and atmosphere

that may affect the biotic environment (Oxford-Dictionary., 2000). For the purpose of this

study the term abiotic factors refer to two elements, which are temperature and relative

humidity. Data for both temperature and relative humidity were collected using a data

logger devise called HOBO H8 Pro Series (BoxCar, 2001), which automatically logged

readings in the devise itself on an hourly basis.

This devise was used to collect data on temperature and relative humidity during

the sampling period (Phase 1 of study). The devise was left on the study site during the

sampling period and removed from the field when sampling ceased. The data was

obtained from the devise once it was plugged into a computer. It is important to note that

the purpose of obtaining this data was to have additional information to support any

inference made on other parameters. No data analyses were conducted and the results

of this sampling method are presented in a descriptive manner in sub-chapter 4.1. This

topic (temperature and relative humidity) is not discussed as a single sub-chapter in

Chapter 5, but instead would be included in the discussions of other related sub-

chapters if necessary.

3.3.2 Habitat description

Methods of assessing and analyzing habitat parameters are numerous with

extensive statistical treatments underlying each method (Smith, 1990; Brower et al.,

1998). Mammals typically are irregular, often patchily distributed in a habitat and

23

individual species occur in microhabitats which are limited subsets of habitats at each

site (Inger & Wilson, 1996). Microhabitat information is useful for determining ecological

distributions of each species but taking such data can be time consuming and may result

in overwhelming data sets which would then be needed to correlate with the use of

habitat for a certain species.

Since microhabitat use by small mammals was not part of the study objectives, the

habitat description or rather the forest strata for each study site were assessed using 12

variables measured quantitatively and four variables measured qualitatively. Each of the

variables were chosen based on the guidelines provided from Dueser & Shugart (1978).

The list of variables and each of its unit of measurement is given in Table 3.3. For

reference purposes, types of common families and species vegetation occurring at

elevations 500m and 900m as described by Kochummen (1982) is given in Appendix

1.0.

3.3.2.1 Sampling techniques

Sampling for habitat assessments were conducted using the trapping points of

the grid as a focal point with a five meter radius around each point. Within this area of a

five meter radius, 16 variables were measured. At both sites, each grid had 100 trapping

points with a 10m interval between points comprising an area of 8100m2. On the whole,

the 16 variables were measured in area of 7855 m2 (size of each sampling area x 100

points; π r2x100 = 7855, π = 3.142, r = 5m.) Thus, almost 97% of the total area of the

grid was sampled.

For the four variables measured qualitatively, the percentage of cover was

estimated using the six coverage classes according to Gysel & Lyon (1980). The six

coverage classes are 0-5%, 5-25%, 25-50%, 50-75%, 75-95% and 95-100%. Canopy

height or rather the height of the tallest tree was estimated using the formula suggested

by

24

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