East of Cascade Range and Sierra Nevada, however, much of breeding population apparently departs for winter. Some wandering apparent, especially in late summer, including limited upslope movements. Incubation lasts 12-14 days. Altricial young tended by both parents. Young leave nest at 14-16 days, but fed by parents for several days thereafter.
House sparrows are strong competitors for nest sites.
Life Histories of North American Cardinals, Grosbeaks, Buntings, Towhees, Finches, Sparrows, and Allies. Bergtold, W. H. 1913. A study of the house finch. Ehrlich, P. R., D. S. Dobkin, and D. Wheye. The Birder's Handbook.