Ecology 6th Edition by Charles Krebs

Exercise 9

The introduced house sparrow (Passer domesticus) competes with the native house finch (Carpodacus mexicanus) in the western United States for nesting sites, and the house finch seems to lose out more frequently in interference competition both at feeders and at nest sites, even if nesting sites are not limited. In 1940 the house finch was introduced into the eastern United States. Discuss the potential impact of this eastern introduction of the house finch on the house sparrow, and list the observations and experiments you would like to do to investigate this species interaction. Bennett (1990) summarizes data on these species.