What if? You can't really do anything, just don't mess with the eggs or nest.
A Cukoo Bird builds it's nest in a chimney
if you like bird feces
nest
cattle bird
The Weaver builds a nest out of grasses, with the entrance at the bottom.
Hummingbirds. The nest of the bee hummingbird, the smallest bird in the world, is only 3cm in diameter.
an eagle builds a nest called an aerie
penguins don't build nests
The nests of cave swifts are used in bird's nest soup.
Swallows? Swallows?
egrets they are called egrets
6-8 weeks