ESTIMATING THE ABUNDANCE OF SAMBAR DEER(Cervus unicolor unicolor) AT THE HORTON PLAINS NATIONAL PARK Of SRI LANKA

Abstract

A study was conducted during the period 1997-2000 to estimate the sambar population atthe Horton Plains National Park of Sri Lanka using direct and indirect method. Vehiclebased spot light technique was used as the direct method and fecal accumulation methodwas used as the indirect method. The defecation rate of sambar used in the indirect methodwas estimated by, a study carried out in the National Zoological Garden Dchiwala, usingeight-penned sambar. The mean defecation rate of sambar deer [or the eight focal samplingat the Zoological Garden - Dehiwala was twenty-one pellet groups / sambar/ day (range =20,17- 30). Results of ANOVA revealed that there is a significant variation in defecationrate with age (P< 0.05, Sig-0.02) but it is not significant sex (P< 0.05, Sig-0.09).

Altogether 688 transects were run for the direct method. For the indirect method, 200quadrats measuring 25m*25m size were sampled. Standard equations were used [or thepopulation analysis. The estimated sambar population, crude density and ecological densityof the direct and indirect methods are 2102.5=Bl845, 66.5Ikm2, 223.5Ikm2 and3154=B 11096, 98.9km2, 350lkm2 respectively.

Results indicated that the values obtained by the indirect method are higher than the valuesobtained [rom the direct method. The reliability of the indirect method depends on theactual daily defecation rate of sambar deer, which depends on the habitat use. Directmethods are more reliable but not feasible at all times. However indirect method can beused to obtain information on population trends. The results of this study indicate anincrease in sambar deer population at the Horton Plains National Park when comparedwith estimates made in 1991.