Determining Minimum and Optimum Viable Population Size of Banteng (Bos javanicus) Based on Demographic Parameters at Alas Purwo National Park, Banyuwangi, East Java

Abstract

One of the main goals of conservation is to maintain sustainability and to increase the population size of living species. In order to conserve an important wildlife population, Minimum Viable Population (MVP) and Optimum Viable Population (OVP) are the main population parameters that must be known. Banteng (Bos javanicus) are protected by the conservation law yet on the other hand has a great economic value for human. Research on MVP of banteng has not yet been performed up until now, and this was the main reason for undertaking a certain study. The aims of this study were to determine MVP and OVP of banteng as a basic point of wildlife management. To obtain the actual condition of the population (population size, sex ratio and age classes) an inventory method of Concentration Count was used, performed in Sadengan grazing field. Based on the assumption that all banteng would gather at this certain location, the counting was performed within 18 repetition and the largest counted number was then considered as the population size. The Algebra linear equation system from Leslie’s matrix was used to determine MVP, while the density dependence of Leslie’s matrix was used to determine the OVP. The population size used as base of calculation was the size of female population, and as for the male population size was predicted using the initial population’s sex ratio. The result showed that the MVP of banteng in Alas Purwo National Park was 94 with the domination of females in each of age classes, which predicted would occur in a year ahead (2013). As for the OVP was 149, also dominated by females and predicted to be occured in the next 30 years (2024).