Q. How long do birds incubate their eggs, and how long do the
chicks stay in the nest?
A. The time for incubation varies widely from species to species. You can
get this information for any species you're interested in by going to its page
in the Cornell Lab of Ornithology's All About Birds
species guide. Once you've found the species you're interested in, click on
"Life History" and then scroll down to "Nesting." Some examples - the eggs of a Black-capped chickadee are incubated for 12-13 days, vs a bald eagle who incubates for 34-36 days. The nestling period also ranges widely for these two species - 12-16 days, vs 56-98.