In an interesting memoir by Rondani, published in the Bolletino del Comizio agrario di Parma for December, 1868, it is maintained that birds are often injurious to the agriculturist, by preying not only on noxious insects, but sometimes exclusively, or at least by preference, on Entomophagous tribes which would otherwise destroy those injurious to cultivated plants.
"The Earth as Modified by Human Action"
George P. Marsh