Ecology and Behaviour of Tarsius Syrichta in the Wild
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O',F Tarsius syrichta ECOLOGY AND BEHAVIOUR - IN BOHOL, PHILIPPINES: IMPLICATIONS FOR CONSERVATION By Irene Neri-Arboleda D.V.M. A thesis submitted in fulfillment of the requirements for the degree of Master of Applied Science Department of Applied and Molecular Ecology University of Adelaide, South Australia 2001 TABLE OF CONTENTS DAge Title Page I Table of Contents............ 2 List of Tables..... 6 List of Figures.... 8 Acknowledgements... 10 Dedication 11 I)eclaration............ t2 Abstract.. 13 Chapter I GENERAL INTRODUCTION... l5 1.1 Philippine Biodiversity ........... t6 1.2 Thesis Format.... l9 1.3 Project Aims....... 20 Chapter 2 REVIEIV OF TARSIER BIOLOGY...... 2t 2.1 History and Distribution..... 22 2.t.1 History of Discovery... .. 22 2.1.2 Distribution...... 24 2.1.3 Subspecies of T. syrichta...... 24 2.2 Behaviour and Ecology.......... 27 2.2.1 Home Ranges. 27 2.2.2 Social Structure... 30 2.2.3 Reproductive Behaviour... 3l 2.2.4 Diet and Feeding Behaviour 32 2.2.5 Locomotion and Activity Patterns. 34 2.2.6 Population Density. 36 2.2.7 Habitat Preferences... ... 37 2.3 Summary of Review. 40 Chapter 3 FßLD SITE AI\D GEIYERAL METHODS.-..-....... 42 3.1 Field Site........ 43 3. 1.1 Geological History of the Philippines 43 3.1.2 Research Area: Corella, Bohol. 44 3.1.3 Physical Setting. 47 3.t.4 Climate. 47 3.1.5 Flora.. 50 3.1.6 Fauna. 53 3.1.7 Human Population 54 t page 3.1.8 Tourism 55 3.2 Methods.. 55 3.2.1 Mapping. 55 3.2.2 Geographic Information Systems (GIS). 56 3.2.3 Mistnetting and Hand Capture. 57 3.2.4 Morphological Measurements. 63 3.2.s Radiotelemetry... 65 3.2.6 Habituation... ... 67 3.2.7 Informal Behavioural Observations. 67 3.2.8 Population Density. 68 3.2.9 Vegetation Survey... 69 3.2.10 Rainfall Data Collection. 7l Chapter 4 HOME RANGES, SPATIAL MOVEMENTS ANI) HABITAT ASSOCIATIONS 72 4.1 Introduction.......... 73 4.2 Methods.. 74 4.2.1 Radiotelemetry... 74 4.2.2 Radiotelemetry Bearing Accuracy 76 4.2.3 Independence of Movements. 79 4.2.4 Habitat Classifications. 79 4.3 Results.... 80 4.3.r Triangulation Bearing Accuracy. 80 4.3.2 Home Ranges. 80 4.3.3 Sleeping Sites. 89 4.3.4 Movements and Activity Patterns 9l 4.3.5 Habitat Associations... .. 96 4.4 I)iscussion 102 4.4.1 Home Ranges. 102 4.4.2 Movement Patterns. t04 4.4_3 Habitat Associations... .. 105 4.5 Summary 107 Chapter 5 SOCIAL ORGANIZATION AND REPRODUCTIVE BEHAVrOUR......... 109 5'1 rntroduction""""" 1lo 5.2 Methods 111 J DAge 5.3 Results.... 111 5.3.1 Morphometrics and Body Weights. 11r s.3.2 Home Range Overlap. 113 s.3.3 Resource Distribution... ... tt6 s.3.4 Communication. tt7 5.3.5 Reproductive Behaviour ... t17 5.3.5.1 Birth months and Parent¿l Care. tt7 5.3.5.2 Testicular size... 118 5.4 Discussion 118 5.5 Direction for future research.. l2l Chapter 6 FORAGINGAI\[D TRAVELLINGBEHAVIOUR.............. 123 6.1 Introduction.......... 124 6.2 Methods.. t24 6.2.1 Behavioural Observations.. 124 6.2.2 Data Analyses... 126 63 Results.... 128 6.3.1 Activities Recorded by 5-minute Interval Sampling... 128 6.3.2 Foraging. 128 6.3.3 Travelling. 133 6.4 l)iscussion. 138 Chapter 7 POPULATION VIABILITY ANALYSIS............ t4t 7.1 Introduction.......... 142 7.2 Methods.. 144 7.2.1 The PVA Model. 144 7.2.2 Data Input to ALEX. 145 7.2.2.1 Age Classes and Mortality.. l4s 7.2.2.2 Litter Size and Sex ratio... 146 7.2.2.3 Home Range Size.. t47 7.2.2.4 Environmental Variabilrty. 147 7.2.2.5 Catastrophe... ... 148 7.2.2.6 Biomass Function. 149 7.2.3 Analysis.. t49 7.2.3.1 Minimum Viable Population 149 7.2.3.2 Sensitivity Analysis. 149 7.2.3.3 Catastrophe and Patch Variation. 151 4 DAge 7.3 Results.... 152 7.3.r Minimum Viable Population and Habitat Area' 152 7.3.2 Sensitivity Analysis. 153 7.3.3 Catastrophe and Patch Variation. 153 7.4 Discussion 158 ChapterS CONSERVATION... r62 8.1 Introduction.......... 163 8.2 Legislation Efforts.... 163 83 Management Options............ t64 8.3.1 Captive Breeding. 164 8.3.2 Ecotourism 165 8.3.3 Local Communities... .. 16s 8.3.4 Protected Areas. 168 8.4 ConclusionsandRecommendations.. t7l References Cited...... 173 Appendices............ 192 I Taxonomic list of identiflred tree specles... 193 2 Importance Value Index of tree species identified.. r97 3 Minimum Convex Polygons of areas covered during continuous tracking sessions. 199 4 Home ranges estimated from discontinuous point data. 206 5 Kernel 95o/o and 50% probability polygons... ... 213 6 Morphological measurements of Tarsius syrichta. 220 i Home range overlap of adjacent males and females using Kernel 95%... 222 I Foraging and travelling data. 227 9 Foraging and Travelling fitted Models.. 231 5 LIST OF TABLES DAge Table2.l Mode of Locomotor, activity patterns, support type and substrate use frequencies offree ranging tarsiers. 35 Table 3.1 Trapping records at Corella, Bohol in 1999. 62 Table3.2 Description of the morphological measurements taken on the living tarsier T. syrichta individuals 64 Table 3.3 Definition of the behavioural states recognised during the study.. ' . '. 69 Table 4.1 Basic information on radio-tracking for estimation of home range of tarsiers. 86 Table 4.2 Philippine tarsier home range estimates calculated for minimum convex polygon (MCP) and Kernel analysis (KER) 95%.. 87 Table 4.3 List of sleep trees. 90 Table 4.4 Summary of continuous (15 min) tarsier fiacking results for 12 hour shifts. 93 Table 4.5 The mean distance travelled per hour by females in varying reproductive states. 96 Table4.6 Range use of individual tarsier using continuous 12-hour tracking... 98 Table 4.7 Support diameter (cm) used for foraging... ... 101 Table 4.8 Support diameter (cm) used for travelling..... 102 Table 4.9 Reported home range of different wild tarsier species in various habitat types from radiotelemetry studies r03 Table 4.10 Most preferred substrate types and sizes of different free ranging tarsier species. 106 Table 5.1 Relative weight of the transmitter package for each individual and changes in body weights during capture. lt4 Table 5.2 Sex differences in numerous morphological measurements. 115 Table 5.3 Percentage overlap of home ranges of adjacent individuals using the 95% Kernel home range. 116 Table 5.4 Infant-mother weight ratio. 118 Table 5.5 Testis-body weight ratio. 118 Table 6.1 The range of information collected for each factor of interest: the type of activity, the substrate used and locomotor mode. t25 Table 6.2 The number of 5-minute behavioural sampling on selected activities in relation to the substrate used.. 128 Table 6.3 Summary of models fitted for foragingiJørtz.. 129 Table 6.4 Expected mean number of foraging activities for each substrate...... 130 Table 6.5 Expected mean number of foraging activities for each locomotor type used.. 130 Table 6.6 Mean height used by T. syrichta while foraging as influenced by substrate... t33 Table 6.7 Mean height used by T. syrichta while foragng as influenced by locomotor type... 133 Table 6.8 Summary of models fitted for travellingdata. 134 Table 6.9 Expected mean number (and standard enor) of tavelling movements for substrate by locomotion interaction 135 Table 6.10 Mean height used by T. syrichta while travelling as influenced by substrate and different modes of locomotor....... t37 6 page Table 7.1 Values of the life history and environmental parameters used in ALEX for the metapopulation analyses of the T' syrichta 150 Table7.2 Values of the catastrophe and movement parameters used in ALEX for the metapopulation analyses of the T. syrichta 151 Table 8.1 The ten pnority sites under the National lntegrated Protected Area System (NIPAS). 168 7 LIST OF FIGURES DAge Figure 1.1 Philippine tarsier Tars ius syrichta... 18 Figure 2.1 Geographical distribution of T. syrichta 23 Figtre2.2 Map of Southeast Asia showing the distribution of recognised tarsier species. 25 Figure 2.3 Map of Sulawesi showing sites cited in the literature.. 26 Figure 3.1 Philippine faunal region and tectonic features.. 45 Figure 3.2 Map of Bohol.... 46 Figure 3.3 Map of Corella.. 48 Figure 3.4 Topographical map of the study site... 49 Figure 3.5 Monthly rainfall in Corella, Bohol during 1999. 51 Figure 3.6 Annual rainfall in Bohol over 35 years. 5l Figure 3.7 GIS Procedure Flowchart... .. 58 Figure 3.8 GIS Analysis Flowchart... 59 Figure 3.9 Trapping sites in Corella and Sikatuna, Bohol.. 60 Figure 3.10 Vegetation survey sites in Corella and Sikatuna, Bohol. 70 Figure 4.1 Bearing triangulation geometry 77 Figure 4.2 Habitat map of the study site... 8l Figure 4.3 a Habitat gradient showing different classifications based on &b vegetation types. 82 Figure 4.4 Grassland corridors. 83 Figure 4.5 Agricultural land habitat classification based on land use... 83 Figure 4.6 Swamp representing the only body of water in the study site... ....... 84 Figure 4.7 Birth months for the collared and other non-collared females. 86 Figure 4.8 Incremental area plot of the radiotagged tarsiers.. 87 Figure 4.9 Minimum convex polygon (MCP) home ranges. 88 Figure 4.10 Types of sleeping sites used by study individuals 90 Figure 4.11 Nightly activity patterns of I I tarsier individuals..... 92 Figare 4.12 Nightly activity patterns of individuals2T30 and 4505.