Jennifer Welsh Wired Science 9 Apr 10;
Birds, bats and lizards may play an important role in Earth’s climate by protecting plants from insects that forage on foliage. A new study suggests that preserving these animals could be a low-tech way to fight climate change.
“The presence, abundance and diversity of birds, bats and lizards, the top predators in the insect world, has impacts on the growth of plants,” said ecologist Daniel Gruner of the University of Maryland, co-author of the paper published April 5 in Proceedings of the National Academy of Sciences. “If you don’t have plants, you don’t have organisms that are recapturing carbon.”
Because these animals feed on both plant-eating and insect-eating bugs in equal numbers, it was believed they wouldn’t have a net effect on plant growth: When the animals gobble up the plant-eating insects, the population of these harmful insects decreases. But, when the animals feed on insect-eating insects, there are fewer predators to eat the herbivores.
The new meta-analysis indicates this is not the case. The presence of insect-eating animals has a positive effect on the growth of plants.
Gruner’s team analyzed the results of 113 studies removing birds, bats and lizards from habitats on four continents and quantified the effect of removing the animals on the population levels of insects and on plant growth.
Things like habitat loss, disease and climate change are affecting the future of these insectivore species. Some of them are thought of as vermin and are killed off by humans. Preserving these creatures will be an important part of keeping ecosystems in check, Gruner said. He also stresses the need for larger, more comprehensive studies of these ecosystems to determine the precise mechanism of how these animals play their protective role.
