Abstract
Baseline data on distribution and abundance of tigers in the Sundarbans is required to identify problem areas and evaluate management strategies. This paper outlines a khal (creek) bank survey of track set frequency throughout the Bangladesh Sundarbans to aid formulation of a management-driven monitoring program. Three teams of two observers surveyed a total of 1 201 km of waterways throughout the Sundarbans, recording 1 338 tiger track sets. These sets became unrecognizable as tiger sign after a mean 10 days (range 6-14). Proportion of detectable sign recorded was 0.91. Mean (±standard error) sample unit track frequency was 1.12 ± 0.86 track sets/km of khal. The mean coefficient of variance in sample unit track rate, estimated by multiple counts of six sample units, was 0.21 (range 0.06-0.34). Track frequency generally increased from northeast to southwest. Four sample units (6%) had signs of reproduction, with a mean litter size of 1.75 ± 0.5. Monte Carlo simulation suggests a monitoring program of one complete survey every two years will have power of 0.8 (α = 0.2), to detect track frequency declines of ≥19% and increases of ≥17%. We recommend this monitoring scheme be implemented on the Indian side of the Sundarbans to provide a standard assessment of the tiger population and to form the basis for setting management objectives and evaluating transboundary conservation initiatives.
Original language | English (US) |
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Pages (from-to) | 2032-2040 |
Number of pages | 9 |
Journal | Biological Conservation |
Volume | 141 |
Issue number | 8 |
DOIs | |
State | Published - Aug 2008 |
Bibliographical note
Funding Information:This study was only possible through the much appreciated support from the Forest Department of Bangladesh. Funding for the survey came from the US Fish and Wildlife Service, Banglalink and the University of Minnesota’s Agricultural Experiment Station. Md. Mozahurul Islam (Divisional Forest Officer, Sundarbans West), S. M. Shahidullahl (Divisional Forest Officer, Sundarbans East), and Md. Rahul Amin (Assistant Conservator of Forests, Satkira range) provided valuable logistical support. We are grateful to Anwar Hossain, Tariqul Islam, Floris Deodatus, and Ullas Karanth for discussions and field testing this approach to tiger monitoring. A large group helped conduct the survey in the field; in particular, we very much appreciate the hard work and dedication of Md. Naser Mia, Khairul Hossain and Abul Kallam Shodar. Earlier drafts of this document were greatly improved by comments from Francie Cuthbert, Peter Cutter, Christina Greenwood and three anonymous reviewers.
Keywords
- Abundance
- Adaptive management
- Panthera tigris
- Power analysis