Abstract
Assessing the population dynamics and demography of long-lived species can be challenging due to longer lifespans and slow reproductive rates. The population status and demography of the Asian elephant was studied from Dec 2006 to May 2008 at Mudumalai Tiger Reserve. The results were compared with previous studies (1985 and 2000) conducted in the study area to understand temporal changes in the elephant population. Distance sampling and mark-recapture methods were used to estimate elephant density in wet and dry seasons. A total of 651.5 km was sampled using transect method. For the capture–recapture method, 17 routes were monitored fortnightly. The sampling effort was 128.5 km. The estimated elephant density based on capture–recapture and distance sampling was 3.4 and 3.6/km2 respectively. The current estimate is higher than previous estimate (1/km2 in 1985 and 2.4/km2 in 2000). The adult male to adult female ratio was 1:20. Tuskless male makhnas accounted for 20% of the male population. Demography data showed that there has been an increase in the number of males in the population. However, the lack of older bulls in the population and the mortality of males through retaliatory killing require further investigation. Natural causes such as disease, injuries, and predation by tigers (two calves) accounted for a major percent (61%) of mortality. Sex-biased changes in mortalities have occurred over time. While adult and sub-adult male mortalities were higher (83%) in the earlier study period, adult female mortalities were higher (54.5%) in the present study. Despite the skewed sex ratio, elephant population has increased in the study area.