The male is hilarious and demonstrative, the female serious and anxious about her charge. ... If his life is all poetry and romance, hers is all business and prose. ....She shows no affection for the male, no pleasure in his society; she only tolerates him as a necessary evil, and, if he is killed, goes in quest of another in the most business-like manner, as you would go for the plumber or the glazier. In most cases the male is the ornamental partner in the firm, and contributes little of the working capital. With the bluebirds the male is useful as well as ornamental. He is the gay champion and escort of the female at all times, and while she is sitting he feeds her regularly. It is very pretty to watch them building their nest.
- John Burroughs, The Bluebird, 1867