Day 8: Eight Maids a Milking

Hmm, birds…milking…where’s the connection?

Wait! Did you know that some birds feed milk to their young? Crop milk is a nutritious substance composed of cells sloughed from the lining of the crop. Adult birds of both sexes feed the substance to their young for the first few days of life. Not all birds produce crop milk; only pigeons and doves, flamingos, and males of some species of penguin. Interestingly, although crop milk is quite different from mammalian milk, its production is stimulated by prolactin, the same hormone that stimulates milk production in mammals!