Estimation of the fruit bat population in the Kampala Bat Valley, Uganda

A population estimate of fruit bats was carried out in the Kampala Bat Valley roost. The model used was a single-stage systematic sampling of unequal primary units (trees). The trees were first listed in a ‘serpentine manner’ with neighbouring trees having contiguous serial numbers. After a random start, every seventeenth tree was selected so that a sample of fourteen out of a total of 238 trees were counted. The exercise was carried out over 3 months, January, February and March, in 1979.Information was gathered on the number of branches with bats, the number of bat clusters and cluster size. From the analysis of the data, the following monthly averages were obtained: total number of bats in the colony = 70,388; average number of bats on each tree = 310; average number of clusters per branch=4; average cluster size = 7.8. Measures of reliability of the estimates were made. The implications of these results and the conservation of the habitat are adjusted.