Milk: Not Just from Moms, Not Just for Mammals
I recently realized that you can't really have a milk mustache if you don't have lips. I guess that means we won't be seeing pigeons in any upcoming dairy ad campaigns- even though they make "milk," and it functions like the milk of mammals. by L. Lan Danny “Pigeon milk” was first systematically described in the 1930s and continues to intrigue dairy scientists through today. Pigeon chicks (known as squabs) hatch in a relatively undeveloped state, but during the first days after hatching, they show accelerated development. During this time, female and male pigeons shed “milk” from the epithelial cells in their crop, an enlarged compartment in the gullet in which food is stored prior to digestion. This chunky substance is rich in fats and proteins and is regurgitated to provision the squabs (Davies, 1939). Pigeon “lactation,” as well as parenting behavior, is hormonally regulated by prolactin, as is the case in mammals (reviewed in Horseman and Buntin, 1996).