medieval England, squab meat was highly valued, although its availability depended on the season. In England, pigeon meat was eaten when other food was rationed during the Second World War and remains associated with wartime shortages and poverty. This was parodied in an episode of the sitcom Dad's Army, "Getting the Bird". Nevertheless, many people continue to eat it, especially the older generation. Husbandry Squab have been commercially raised in North America since the early 1900s. As of 1986, annual production in the United States and Canada was one and a half million squabs per year. Pigeons, unlike other poultry, form pair bonds to breed, and squabs must be brooded and fed by both parents until they are four weeks old; a pair of pigeons may produce 15 squabs per year. Ten pairs can produce eight squabs each month without being fed by their keepers. Pigeons which are accustomed to their dovecote may forage and return there to rest and breed. Industrially raised pigeons have young which weigh when of age, as opposed to traditionally raised pigeons, which weigh . Utility pigeons have been artificially selected for weight gain, quick growth, health when kept in large numbers, and health of their infants. For a greater yield, commercially raised squab may be produced in a two-nest system, where the mother lays two new eggs in a second nest while her offspring are still growing in the first nest, fed crop milk by both parents. Establishing two breeding lines has been suggested as another strategy for greater yield, where one breeding line is selected for prolificacy and the other for "parental performance", which, according to Aggrey and Cheng, is "vital" for squab growth after the age of two weeks. Meleg estimates that 15–20% of eggs fail to hatch in well-maintained pigeon lofts. Egg size is important for the squab's initial size and for mortality at hatching, but becomes less important as the squab ages. Aggrey and Cheng feel that the hatched weight of squabs is not a good indicator of their weight at four weeks old. Squabs reach adult size, but are not yet ready to fly (making them easier to catch) after roughly a month; at this point, they are slaughtered. In cuisine Usually considered a delicacy, squab is tender, moist and richer in taste than many commonly consumed poultry meats, but there is relatively little meat per bird, the meat