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Evaluation of Line Transect Sampling Technique in Estimating Elephant Abundance in Forests Using Dung Survey
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Line transect sampling technique is widely applied for estimating the biological population in forests. Recently, this technique has been in use for the estimation of elephant abundance using dung survey. The method of transforming dung count into elephant density requires dung density, which is corrected by defecation and decay rate. In this paper, the performance of the line transect sampling technique (LTS) in dung surveys with particular reference to variation in the number of detections of dung piles caused by annual rainfall variability was evaluated. The data set for this purpose was from the estimation of elephant population in the State of Kerala during the years 2005, 2007 and 2010, covering about 9000 km2. The study showed that the presence of dung piles and its detection probability were dependent on the level of rainfall in the two months preceding the date of dung survey. However, the LTS could provide comparable dung density estimates under the highly varying number of dung piles present in the area due to differences in the annual rainfall pattern.
Keywords
Distance Sampling, Detection Probability, Elephant Density, Rainfall Variability.
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- Anderson D.R. and Southwell C. (1995). Estimates of macropod density from line transect surveys relative to analyst expertise. J. Wild Manage, 59(4): 852-857.
- Barnes R.F.W., Asamoah-Boateng B., Majam J.N. and Agyei-Ohemeng J. (1997). Rainfall and the population dynamics of elephant dung-piles in the forests of southern Ghana. Afr. J. Eco., 35: 39-52.
- Barnes R.F.W. and Dunn A. (2002). Estimating forest elephant density in Sapo National Park (Liberia) with a rainfall model. Afr. J. Eco., 40: 159163.
- Borchers D., Margues T., Gunnlaugsson and Jupp P. (2010). Estimating distance sampling detection functions when distances are measured with errors. J. Agricultural, Biological and Environmental Statistics, 15: 346-361.
- Buckland S.T., Anderson D.R., Burnham K.P., Laake J.L., Borchers D.L. and Thomas L. (2001). Introduction to distance sampling: Estimating abundance of biological populations,Oxford University Press Inc, New York.
- Buckland S.T., Anderson D.R., Burnham K.P., Laake J.L., Borchers D.L. and Thomas L. (2004). Advanced Distance Sampling, Oxford University Press Inc, New York.
- Buckland S.T., Plumptre A.J., Thomas L. and Rexstad E.A. (2010a). Line Transect Sampling of primates: Can animal-to-observer distance methods work? Int. J. Primatol., 31: 485-499.
- Buckland S.T., Plumptre A.J., Thomas L. and Rexstad E.A. (2010b). Design and analysis of line transect surveys for Primates. Int. J. Primatol., 31: 833-847.
- Burnham K.P., Anderson D.R. and Laake J.L. (1980). Estimation of density from line transects sampling of biological populations. Wildlife Monographs, 72: 202.
- Forcard S., Isotti R. and Tinell A. (2002). Line transect estimates of ungulate populations in a Mediterranean Forest. J. Wild Manage, 66(1): 48-58.
- Guthery F.S. (1988). Line transect sampling of probable density of Rangeland: Evaluation and recommendations. Wildlife Society Bulletin, 16: 193-203.
- The Hindu (2012) The Hindu archives. http://www.thehindu.com/navigation/?type=static&page=archive, accessed on 30 April 2012.
- Mercey K.A. and Jayaraman K. (1999). Predicting the variation in detection function in line transect sampling through random parameter model. Environmental and Ecological Statistics, 6(4): 341-350.
- Mercey K.A. and Jayaraman K. (2002) Effect of errors in visual assessment of distance in line transect sampling. In: Proceedings of the 14th Kerala Science Congress 29-31 January 2002 (M.R.Das eds), Science and Technology Department, Government of Kerala, Thriuvananthapuram, 2002, pp. 455-458.
- Mercey K.A., and Jayaraman K. (2004). Detection function models for indirect evidence of elephant and gaur. Indian Forester, 130(10): 12011203.
- Sivaram M., Ramachandran K.K., Nair P.V. and Jayson E.A., Population estimation of Wild Elephants in the Elephant Reserves of Kerala State2005, Kerala Forest Research Institute, Peechi, KFRI Extension Report, 2005, No.18, p.46.
- Sivaram M., Ramachandran K.K., Nair P.V. and Jayson E.A. (2007). Population estimation of Wild Elephants in the Elephant Reserves of Kerala State-2007, Kerala Forest Research Institute, Peechi, KFRI Extension Report, No.27, p.40.
- Sivaram M., Ramachandran K.K., Jayson E.A. and Nair P.V. (2010). Wild Elephant Census of Kerala State-2010, Kerala Forest Research Institute, Peechi, KFRI Extension Report, 2011, No.52, p.40.
- Thomas L., Laake J.L., Strinberg S., Marques F.F.C., Buckland S.T., Borchers D.L., Anderson D.R., Burnham K.P., Hedley S.L., Pollard J.H., Bishop J.R. and Marques T. A. (2006). Distance 5.0, Release 2, Research Unit for Wildlife population Assessment, University of St. Andrews, U.K.
- Turnock B.J. and Quinn II T.J. (1991). The effect of responsive movement on abundance estimation using line transect sampling. Biometrics, 47: 701-715.
- Varman K.S., Ramakrishnan U. and Sukumar R. (1995). Direct and indirect methods of counting elephants: A comparison of results from Mudumalai Sanctuary. In: A week with Elephants: Proceedings of the International Seminar on Asian Elephants (J.C. Daniel, J. C. and S.H. Datye eds),Oxford University Press, New Delhi.
- White G.C., Bartmann R.M., Carpenter L.M. and Garrot R.A. (1989). Evaluation of aerial line transects for estimating deer densities. J. Wild Manage, 53(3): 625-635.
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