We've had mourning doves nesting in our backyard evergreen trees all summer.
They're good parents--far more attentive than the human ones who share the space! They lay two eggs at a time, and almost never leave them alone. The male usually incubates from midmorning until late afternoon, and the female tends them the rest of the time. (Warning: gross fact ahead!) Mourning doves of both sexes feed their hatchlings something called "pigeon milk"--a substance that oozes from the lining of the parent's crop and contains more protein and fat than either human or cow's milk. Hatchlings eat nothing but pigeon milk until they're three days old; after that, they're gradually weaned onto a diet of seeds. The parents continue to feed the hatchlings until they're totally feathered out.
The crazy part is that mourning doves can produce five or six sets of chicks each year. (This may be one reason why mourning doves are among the ten most abundant birds in the US...) If things at the first nest are going well, the parents will build a second one nearby. One adult feeds the older chicks, while the other sits on the new eggs. It's a baby bird factory!
Right now, we have a couple of newly-fledged doves running around on the ground. I think the parents are still feeding them occasionally. And there's a new set of hungry hatchlings to feed, too. Makes me feel lazy for complaining about keeping up with my two little ones!
Mourning doves are related to pigeons. Here's a great article on why you never see baby pigeons.