Chimney Swifts are small birds that typically build their nest in chimneys or abandoned buildings. These migratory birds leave in early November to winter in the Amazon Basin of Peru. They return to the continental United States in late march.
The entire nesting process takes about 30 days. Both sexes participate in nest building and incubation of the eggs. At around day 28, the young hatchlings will start to leave the nest. Soon after, all of the birds will leave the nest.
The nests that these birds build are highly flammable, and must be removed. However, you can’t do that until the nest is empty. The Migratory Bird Treaty Act (MBTA) prohibits people from taking migratory birds, their eggs, feathers or nests. In total, 836 bird species are protected under the MBTA.
So, remember that Chimney Swifts are not to be disturbed until they leave the nests. However, once they are gone, it is highly recommended that you remove the empty nests.