Chimneys hold an attraction for all kinds of birds. Some flock to the chimneys on cold mornings for the heat. Others find chimneys resemble naturally occurring geographic features that they find desirable for nesting. Some birds like cavities, like hollow trees, and others like the isolation of the chimney, meaning that most predators won't be able to access the nest.
European white storks
European white storks have been building nests on buildings for hundreds of years. Some homeowners encourage them to build on their homes by adding elements to abandoned chimneys that make it easier to build nests. Other times the stork nests are a major problem because they sometimes build their nests directly on top of functioning chimneys. These nests are large and made of sticks, branches, grass, rags, paper and sod. The storks usually lay about three to five eggs and incubate them for 33 to 34 days. Some think it is this habit of nesting on chimneys that started the legend of storks delivering babies.
Jackdaws are members of the crow family that nest in cavities such as old trees and chimneys. Jackdaws are black with grey shading around the head and neck. The like open areas near animals, where they can find plentiful insects to feed. The nest is made of twigs, straw, paper, hair and feathers. The jackdaws lay four to six eggs in April or June and the eggs hatch about three weeks later. The nests can be a problem because the birds in chimneys can be noisy, especially once the babies are born. The nesting birds also leave a mess of feathers and droppings in the fireplace. The nests can also be a fire hazard. Removing the nests or putting up devices to keep the birds out of the chimney is recommended.
Chimney swifts are well-adapted to nesting in chimneys. Their feet serve as grappling hooks, enabling them to hold on to vertical surfaces, like the insides of chimneys, but not perch on horizontal surfaces like branches. Chimney swifts spend nearly all their time in the air -- eating, drinking, courting, mating, bathing and collecting sticks for nests. The young birds make noise that is considered annoying to many homeowners. Homeowners are encouraged to leave the nests alone until the birds have fledged and are no longer using the nest. If the homeowner wants to avoid birds in the chimney in the future, he should cover the chimney with chicken wire or a device designed to keep birds out of chimneys.