Bats Limit Insects in a Neotropical Agroforestry System
Kimberly Williams-Guillén,1*
Ivette Perfecto,1
John Vandermeer1,2
Exclosure experiments have demonstrated the effects of bird predation on arthropods. In a Mexican coffee plantation, we excluded foliage-gleaning bird and bat predators from coffee plants. Effects of bats and birds were additive. In the dry season, birds reduced arthropods in coffee plants by 30%; birds and bats together reduced arthropods by 46%. In the wet season, bats reduced arthropods by 84%, whereas birds reduced them by only 58%. We conclude that previous "bird" exclosure experiments may have systematically underestimated the effects of bats.
1 School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI 48109, USA.
2 Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA.
* To whom correspondence should be addressed. E-mail: kimwg{at}umich.edu
