Birds around the world eat 400 to 500 million metric tonnes of beetles, flies, ants, moths, aphids, grasshoppers, crickets and other anthropods per year. These numbers have been calculated in a study led by Martin Nyffeler of the University of Basel in Switzerland. The research, published in Springer’s journal The Science of Nature, highlights the important role birds play in keeping plant-eating insect populations under control. Other predator groups like bats, primates, shrews, hedgehogs, frogs, salamanders, and lizards seem to be valuable yet less effective natural enemies of plant-eating insects.
— source springer.com