Apr 13 2010
Bats, not as bad as you think.
To many, bats are dirty, scary and mysterious while to the fruit farmers, fruit bats are persecuted as pests for the damage they do to their yield. All of these have rendered bats to be among the most hated and most feared animals in the world, hiding under a bushel the importance of fruit bat as a seed-dispersal agent.
The most commonly found fruit bat in Singapore is the Lesser Short-nosed Fruit Bat, Cynopterus brachyotis (Phua, P.B. and Corlett, R.T., 1989). Bearing a dog-like face with large eyes, it is also widely known as the Lesser Dog-faced Fruit Bat (Wild Fact Sheets, 2008). In Singapore, you can find them almost anywhere, ranging from coastal areas, forests, riverside to urban areas (Phua, P.B. and Corlett, R.T., 1989). According to Phua and Corlett (1989), the Lesser Short-nosed Fruit Bat (Cynopterus brachyotis) is a very important seed-dispersal agent for the Tiup-tiup (Adinandra dumosa), which is the dominant species in the secondary forest adjoining to National University of Singapore (NUS) (Phua, P.B. and Corlett, R.T., 1989).
With Tiup-tiup (Adinandra dumosa), the Lesser Short-nosed Fruit Bat (Cynopterus brachyotis) establish a mutualistic relationship. Though A. dumosa fruits all year round but its conspicuous green-hue fruits surprisingly, are not taken by birds or other mammals, but by the C. brachyotis ( Phua, P.B. and Corlett, R.T., 1989). The habit of Lesser C. brachyotis to defecate during its flight has greatly enhanced the dispersal of Tiup-tiup (A. dumosa) seeds to a wide range of habitat. Being the major food source, the Tiup-tiup (A. dumosa) thus maintains high population density of Fruit Bat (C. brachyotis) in the secondary forest (Phua, P.B. and Corlett, R.T., 1989).
One question raised here is why C. brachyotis the sole diepersing agent for A. dumosa. Phua and Corlett (1989) provide an explanation that A. dumosa has evolved over time in favor to be dispersed by the fruit bats. However, the mechanism underlying the evolution is not established. This calls for the study of natural history of both the bats and plants in the university’s secondary forest to explain this specific mutualism.
- “Fruit Bats,” by Kelvin K. P. Lim, Dennis H. Murphy, T. Morgany, N. Sivasothi, Peter K. L. Ng, B. C. Soong et al. URL: http://mangrove.nus.edu.sg/guidebooks/text/2121.htm (accessed on 15 April 2010)
- Phua, P.B. & Corlett, R.T., 1989. Seed Dispersal by the Lesser Short-nosed Fruit Bat (Cynopterus brachyotis, Pteropodidae, Megachiroptera). Malayan Nature Journal, 42: 251-256.
- “Tiup-tiup flowers” by Flickr. URL: http://www.flickr.com/photos/shimmertje/35125906/ (accessed on 9 April 2010)
- Wild Fact Sheets. (2008). Common fruit bat. Retrieved 9 April, 2010, from http://www.wildsingapore.com/wildfacts/vertebrates/mammals/brachyotis.htm