FLOWER VISITING BATS AND DURIAN TREES: SPECIES RICHNESS AND POPULATION SIZE

Abstract

Bats play a vital role in the pollination of durian tree flowers, but its population is shrinking due to climate change and excessive hunting. This study tries to determine the bat species richness and population size in a durian orchard. A simple mark-recapture experiment was conducted using mist nets to tag flower-visiting bats of two durian species — Durio zibethinus and D. lowianus — at the Malaysian Agricultural Research and Development Institute orchard in Jerangau, Terengganu, Peninsular Malaysia. The characteristics and species of captured bats were recorded to estimate the population size using the Schnabel formula for a closed population. A total of 137 individuals were captured, comprising four species — Eonycteris spelaea, Cynopterus brachyotis, C. horsefieldii, and Scotophilus kuhlii. E. spelaea was the most abundant species, representing 53 % of the total captured individuals. The estimated population size of the bats with 95% confident interval was 1,110 individuals per hectare, with an upper range of 10,882 individuals. The large population of bats visiting the durian orchard may indicate the importance of this area as a feeding site, particularly for E. spelaea. This further indicates the significant contribution of these flower-visiting bats in the pollination of durian flowers.