The love-making of the bluebird is as beautiful as the bird itself, and normally as gentle, unless interrupted by some jealous rival who would steal his bride; then gentleness gives place to active combat. The male usually arrives a few days ahead of the female, selects what he considers to be a suitable summer home, and carols his sweetest, most seductive notes day after day until she appears in answer to his call.

Life histories of North American thrushes, kinglets, and their allies: order Passeriformes (ed. 1949)