Bats Limit Arthropods and Herbivory in a Tropical Forest
Margareta B. Kalka,1*
Adam R. Smith,1
Elisabeth K. V. Kalko1,2
Previous exclosure studies measuring the top-down control of
arthropod abundance and herbivory combined the effects of birds
and bats. We experimentally partitioned bird predation from
bat predation in a lowland tropical forest in Panama and measured
the direct effects (arthropod abundance) and indirect effects
(herbivory). The exclusion of birds and bats each directly increased
arthropod abundance on plants: Bird-exclosed plants contained
65% more, and bat-exclosed plants 153% more, arthropods than
controls. Birds and bats also indirectly increased herbivory:
Bird-exclosed plants suffered 67% more, and bat-exclosed plants
209% more, herbivory than controls. We conclude that bats have
dramatic ecological effects that were previously overlooked.
2 Institute of Experimental Ecology, University of Ulm, Albert-Einstein-Allee 11, 89069 Ulm, Germany.
* To whom correspondence should be addressed. E-mail: mbkalka{at}gmail.com
