Chimney swifts are small birds, about 5 inches long, that are found across the eastern half of the United States, including Florida. They are sometimes called “cigars with wings”, because their brown to black bodies are stubby with a blunt tail and long, narrow, curved wings.
Chimney swifts feed on insects that they capture while in flight. Swifts are one of the fastest birds in the world and are entertaining to watch as they fly out of structures in large, chattering flocks to hunt insects and skim surfaces of ponds, lakes or streams.
Swifts spend much of their time in the air, feeding, drinking, gathering nest material, courting and even mating while in flight.
Chimney swift nests are constructed of small twigs woven together and stuck to vertical surfaces with the birds’ glue-like saliva. Nesting can occur one to two times per year each summer. Clutch size is usually three to five eggs, which are white in color. Incubation typically lasts from 16 to 21 days and young fledge between 14 and 19 days after hatching. The total nesting time frame for chimney swifts is between 30 and 40 days.
Chimney swifts migrate to Florida from South America in the spring to reproduce. Chimney swifts need natural vertical surfaces such as caves or hollow trees to build their nests, but these can be challenging to come by. Many chimney swifts choose structures such as chimneys or air shafts as alternative nesting locations. For this reason, they can often be seen in both urban and suburban areas.
Chimney swifts are beneficial because they eat flying insects including mosquitos. Unfortunately, chimney swift populations are declining across their range. If you can tolerate birds using your structure, you may be helping their populations. In most cases, birds temporarily residing in chimneys are not cause for alarm. They can create an annoyance to some as they twitter, call, and fly in and out. They also prevent the safe use of fireplaces while nesting in chimneys. Keep in mind, these inconveniences are temporary since chimney swifts begin their migration southward in fall when nesting is complete. If chimney swifts have nested in your chimney, a cleaning should be scheduled following the nesting season for safe fireplace use.