Again, the witty Bro. Darwin catches an unforgettable scene: “The males (English Pouter pigeons), especially when excited, pout more than the females, and they glory in exercising this power. If a bird will not, to use the technical expression,”play,” the fancier, as I have witnessed, by taking the beak into his mouth, blows him up like a balloon; and the bird, then puffed up with wind and pride, struts about, retaining his magnificent size as long as he can (Darwin 1897, 143) .”
Darwin, Charles. The variation of animals and plants under domestication, Volume I. New York: D. Appleton and Company, 1897.