Canadian Forest Service Publications
The effects of insectivorous bird activities in forest ecosystems: an evaluation. 1979. Otvos, I.S. Pages 341-374 in J. Dickson, R. Conner, R. Fleet, J. Jackson, and J. Kroll, Editors. The Role of Insectivorous Birds in Forest Ecosystems. Academic Press, New York.
Issued by: Pacific Forestry Centre
Catalog ID: 5288
Insectivorous birds play an important role in the forest ecosystem. They have a significant influence on the population dynamics of many forest insects. Birds act as direct mortality agents of insect pests, and they can also affect their prey indirectly through influencing insect parasites and predators on the prey, by spreading entomogenous pathogens, or in some cases by altering the microhabitat of the prey. Birds exert the greatest influence on insect populations at endemic levels; they suppress and delay population build-up to epidemic levels, and thus may increase the interval between insect outbreaks. Insectivorous birds may also accelerate the decline of an outbreak. They may also have an effect on the forest ecosystem by feeding on and by dispersing seeds of various forest trees and shrubs. Some birds may be involved in the spreading of wood rotting fungi and thus contribute to the nutrient recycling.