In much of SE Asia, the Kerivoula and Murina forage for insects in dense forest habitats. Using echolocation to detect prey in such “acoustically cluttered” environments is a challenge because of the problems of forward and backward masking. The role of the extremely broad-band, high-frequency FM sweeps in prey detection in these vespertilionid subfamilies was investigated experimentally with wild-caught bats in Peninsular Malaysia, specifically the relationship between bandwidth and backward masking. Based on work on European Myotis we hypothesized that bats should be able to detect prey close to background. All the tested species were able to catch a suspended mealworm as close as 6 cm from a standardized vegetation-like background, and some as close as 2.5 cm. The performance and call data corroborate the hypothesis that bats with very broadband calls and high-frequency components have access to prey very close to vegetation and establish this as a more general principle in bat sensory ecology.
Schmieder, D. A., Kingston, T., Hashim, R., Siemers, B. M. (2012), Sensory constraints on prey detection performance in an ensemble of vespertilionid understorey rain forest bats. Functional Ecology. doi: 10.1111/j.1365-2435.2012.02024.x
Abstract can be read here. For a pdf, please contact tigga(dot)kingston(at)ttu(dot)edu,
A video explaining the study for a lay audience is here:http://www.youtube.com/watch?feature=player_embedded&v=dQbgC5n7mAI# with a lay summary here http://www.functionalecology.org/view/0/summaries.html#schmieder
The paper is dedicated to our dear friend and colleague Bjoern Siemers, who tragically passed away in May 2012.