Assessing the status of tigers in the Western Forest Complex of Thailand and developing a landscape scale management plan Final Report to the National Fish and Wildlife Foundation October 2002 James L.D. Smith, [email protected] Peter Cutter, [email protected] Department of Fisheries, Wildlife and Conservation Biology University of Minnesota 1980 Folwell Ave. St. Paul, MN 55108 Tel. 612-624-5369 CONTENTS Contents...................................................................................................................................................2 Executive Summary.................................................................................................................................3 Study Area ...............................................................................................................................................4 Capacity building.....................................................................................................................................6 Methods ...................................................................................................................................................6 Tiger Surveys.......................................................................................................................................6 Pellet/dung transects............................................................................................................................7 Interviews ............................................................................................................................................7 Captive Sign Study ..............................................................................................................................8 Results ...................................................................................................................................................10 Geographic Information System (GIS) Database..............................................................................10 Human Impact Patterns .....................................................................................................................11 Prey Base Assessment .......................................................................................................................11 Tiger - Habitat Relationships.............................................................................................................13 Tiger Distribution and Estimated Minimum Breeding Population ...................................................13 Monitoring.........................................................................................................................................13 Conclusions ...........................................................................................................................................14 Acknowledgements ...............................................................................................................................14 References .............................................................................................................................................15 Appendix 1. Maps..............................................................................................................................17 Appendix 2. Photos............................................................................................................................18 ------Tiger Conservation in Western Thailand—Final Report to the National Fish and Wildlife Foundation------ Page 2 EXECUTIVE SUMMARY * Note: Numbered maps referred to in the text can be found at the back of this report. Over a four year period from 1997 to 2000, we surveyed a large portion of the Western Forest Complex--an expansive landscape (~10000 km2) of contiguous, mostly forested protected areas in western Thailand (Map 1) to assess the status of tigers, their prey base, and other factors potentially affecting the tiger population in this area. In particular, we sought to answer the following questions: 1.What proportion of the core area of the Western Forest Complex is occupied by tigers? 2.What are the landscape-scale patterns of tiger prey distribution and quality in this area? 3.What are the landscape-scale patterns of human impact in this area? 4.Are patterns of tiger distribution, tiger prey distribution, and human impacts related? In their macro-scale tiger conservation priority setting exercise, Wikramanayake et al. (1998) identified the Western Forest Complex and surrounding areas as the largest high priority Tiger Conservation Unit (TCU) in Asia and it is likely that this TCU is home to the largest population of tigers in Southeast Asia (Smith et al. 1999b). The area is mostly rugged, mountainous terrain with 2 major river systems and 2 mountain ranges bisecting it. The vegetation is a complex mosaic tropical seasonal forest including dry or semi-evergreen forest, tropical mixed deciduous forest, bamboo forest, and dry dipterocarp forest. Within the survey area, there are approximately 4000 people living in about 35 village sites. Our initial efforts focused on selecting methodologies appropriate to the geographic scale of the investigation and the questions being asked. In most cases, field methods that could be learned quickly, employed consistently, and that were not technology-dependent were selected so as to involve a greater number of people in the process and in so doing, foster greater long-term capacity building. Additionally, a Geographic Information System (GIS) was established at the outset of the project to store, analyze, and display data collected. On over 50 field trips during the course of the project, a core survey team would visit protected areas within the larger study area on a rotating basis to carry out training with protected area personnel and to supervise fieldwork. All of these efforts were focused on both completing the specific goals of the project and building the local capacity and baseline data necessary to continue the work after the completion of the project. Approximately 50 Royal Forest Department (RFD) rangers (4-6 from each of the 5 protected areas surveyed plus several replacements during the course of the project) took part in an intensive 2-3 day practical training course prior to assisting with fieldwork. The training covered wildlife and wildlife sign recognition, basic sampling concepts, forest navigation skills (including the use of handheld GPS units), and other methods specific to this investigation. An original training manual was created to supplement the training. To assess tiger distribution, irregular transect or “recce” style tiger sign surveys (Walsh and White 1999) were conducted on approximately 1880 km of roads, trails, streams, and ridges (Map 4). To assess relative prey abundance, pellet/dung count plots were carried out on 57 km of transects at 114 discrete locations (Map 4). Methods followed those used extensively throughout the Terai area of Nepal (Smith 1984, 1999) allowing for a comparison of relative densities between these two areas. ------Tiger Conservation in Western Thailand—Final Report to the National Fish and Wildlife Foundation------ Page 3 During the course of the study, 150 interviews were carried out at 29 villages and 47 Thai Royal Forest Department (RFD) stations in and around the study area (Map 5). These guided discussions provided additional information on the distribution of tigers (Map 7) and other wildlife (Map 9) as well as valuable insights into patterns of human use and impacts (Map 3). Visits to captive facilities during the course of the investigation resulted in a database of track measurements of tigers of known age and sex and the establishment of objective criteria for estimating the age and sex of tigers whose tracks were measured in the field. Applying these criteria to the pooled “unknown” sign collected during the investigation provides a snapshot of tiger demographics during the survey period (Map 7). An evaluation of these data using very conservative assumptions yields an estimated minimum adult tiger population of 6 males and 21 females within the area surveyed which is roughly 30% of the entire Western Forest Complex. A preliminary assessment of tiger distribution, tiger prey distribution, and human impacts indicates that there is a significant relationship between both tiger distribution and tiger prey distribution and between tiger distribution and human impact patterns. The data collected to date are currently being used to create predictive models of tiger and tiger prey distribution beyond the bounds of the study area with the ultimate goal being a predictive map of tiger distribution in western Thailand and eastern Burma. STUDY AREA The area selected for analysis encompasses five contiguous protected areas near the Thai / Myanmar border. At approximately 10,000 km2, the study area represents the core of a mostly forested landscape known as “the Western Forest Complex” comprised of 17 separately managed protected areas (Map 1). Together with a large area of contiguous forest on the Myanmar side of the border, the area represents the largest TCU (Tiger Conservation Unit) identified by Wikramanayake et al. (1998) in their range-wide tiger conservation priority-setting exercise. Armed conflict and travel restrictions have meant systematic fieldwork has not been carried out on the Myanmar side of the border in recent years. At the southeastern end of the extensive