A mourning dove has been living on my block since we moved in in early February, often perching in a tree on the corner or doing its head-bobbing pigeon walk around the courtyard of our building searching for food. It–only another mourning dove can tell whether it is a he or a she–may have found a mate.
Most mourning doves spend the winter in small flocks, which break into pairs in early spring. Long-term studies suggest that these pairs are permanent, that the birds stay together for life. Of course the mortality rate is very high–about 55 percent per year for adult birds–so a lifetime commitment for most individuals lasts no more than a year.
Best of Chicago voting is live now. Vote for your favorites »
Once the eggs are laid incubation is divided precisely between the sexes, with the male sitting on the nest by day and the female at night. Once the young hatch, after about two weeks, both parents feed them for the next two weeks, the time it takes them to mature to the point that they can leave the nest.
But only pigeons and doves produce milk in their crops. During the breeding season the walls of the crops of both males and females thicken by as much as 20 times. The milk comes from cells that are continuously sloughed off the insides of the walls. It is a cheesy substance, rather like ricotta. About 25 percent of it is fat, and another 10 percent is protein. The blind, helpless chicks stick their heads down their parents’ throats to suck up the milk, which is their sole food during the first ten days to two weeks of life. As they get older they begin to swallow partly digested seeds mixed with the milk. When they leave the nest they are ready for the nearly all seed diet of their parents.
Passenger pigeons nested in huge colonies. Thousands of pairs of birds would gather where the chestnut and beechnut and acorn crops were especially rich and
Unfortunately the strategy could not withstand large numbers of men with shotguns who had boxcars standing by to haul away as many pigeon carcasses as their marksmanship could create. And it couldn’t withstand the loss of habitat created by the greatest clear-cut in history. The sadness in the coo of the mourning dove reminds us that we have something to be sad about.
