Chimney Swifts

National’s chimney swifts

Photo by Larry Stone
Swift Tower at National. Photo by Larry Stone

The tower replica at National was completed in the early summer of 2009, too late to attract a nesting pair of swifts that year. For the next two years, chimney swifts were seen in the area, but none chose the tower for a nest site. The third year, 2012, nesting began at the National tower. Ironically, Althea Sherman reported waiting three years for swifts to choose to nest in her artificial tower at her nearby home. In 2012, the first year, four eggs were laid, but one did not hatch. It remained intact until the swifts left the tower, surviving a 3 foot fall from the nest to the bottom of the chimney.

Swifts have nested in the National tower now for ten years, and 41 young swifts have fledged from the site. This is great news as the chimney swift population is in steep decline.

The swifts return to our area in mid to late May. We’re unable to tell if the same pair return each year as adult swifts look remarkably alike. It’s believed that swifts will return to the nest site they have used in the past, and that the young raised there will also return. We have often seen at least 3 adults flying overhead, and wonder if one is a “helper” to the mated pair, assisting with incubating and feeding the hungry young.   The ability to fledge five young the last two years makes us believe this is an experienced pair of adults who have perfected the art of parenthood.

Adult Swift flying near the Sherman Swift Tower - Photo by Larry Stone
Adult Swift flying near the Sherman Swift Tower. Photo by Larry Stone

Typically nest building begins around Memorial Day, and continues for some time. Egg laying occurs in June and the babies have arrived in July. By early August, they have fledged and are gone from the nest. After this time we have seen swifts roosting at night in the chimney and believe they might be the young raised there the previous summer.

They are a beautiful bird to see and hear and we look forward to seeing them arrive each spring.

A monitor at the Sherman Swift Tower in National allows you to see the swifts on their nest along with an audio recording and signage about Althea Sherman and the swifts.

Young swifts in the Sherman Swift Tower at National, Iowa

Young swifts in the Sherman Swift Tower at National, Iowa. Photo by Deanna Krambeer

More about Chimney Swifts

Chimney swifts (Chaetura pelagica) are small dark birds about 5 inches long with powerful wings and stubby tails. They are often referred to as “cigars with wings” in flight. They are summer residents of Eastern and Central United States and the southern area of provinces in Canada. Insect eaters only, in winter they migrate to regions in South America for an adequate food supply.

They have some unique characteristics. They are powerful fliers, gathering nest material and eating while flying. Mosquitoes are a common food, making the swift a friend to people living near these pesky insects. They do not land on tree branches or power lines or the ground. If they are not flying, they are found clinging to a vertical surface such as the inside of a chimney or on their nest.

Chimney swifts nest primarily in chimneys, which is one reason their population is declining.

Their nests are made of small sticks they break off while in flight, and the nest is held together with their saliva. There is only one nest in each chimney, but multiple birds may roost there with the mated pair and some reports suggest other adult ‘helpers’ may assist in care the young. They can raise 3-5 babies each year.

Most people are unaware of their presence unless they have a nesting pair in their chimney and then the calls and noises of the babies are heard for a period of time in the summer. The nesting birds don’t harm the chimney and the nest is used during the summer when the chimney is not commonly in use.

Swifts made a unique sound, it’s a rapid chip, chip, chip, often referred to as a ‘chippering’ sound. It can be quite audible in a quiet setting, and hearing the birds before seeing them is not uncommon. But their calls can be difficult to hear in an area with other noises, especially bird calls. The young make a loud hissing noise when aroused which is startling in its volume and very un-birdlike.

In 2014, The North American Bird Conservation Initiative identified them as one of 33 common US birds in steep decline. This means they have lost half of their population over the last forty years. Provinces in Canada and other parts of the United States have reported alarming drops in the populations.

For detailed information about the swifts, visit