The chimney swift is a small bird that is found throughout much of eastern North America. Despite its name, it no longer relies solely on chimneys for nesting and roosting. The chimney swift has several unique traits that make it stand out from other birds.
What does a chimney swift look like?
Chimney swifts are gray-brown birds with long, slender wings and short legs. Their body is about 5-6 inches long with a wingspan around 12 inches. The most identifiable feature of the chimney swift is its short, triangular tail. When in flight, the tail appears almost non-existent. The bill is very short but wide at the base with a large gape. The eyes are dark brown. Overall, the chimney swift has a very streamlined, aerodynamic appearance.
Chimney swifts may appear similar to swallows but can be distinguished by their uniform coloration, lack of white markings, and shorter tail. Swifts also have relatively larger heads and eyes than swallows.
Where does the chimney swift live?
The chimney swift is found across most of eastern North America. Its breeding range stretches from Nova Scotia west to Saskatchewan and south to Texas and Florida. Some key areas where chimney swifts nest include:
- Eastern deciduous forests
- Towns and cities with suitable chimneys or other structures
- Open wooded areas interspersed with clearings
Chimney swifts migrate to northwestern South America for the winter. Their wintering grounds center around Peru and Brazil. Some chimney swifts may overwinter in southern Florida if suitable roosting sites are available.
What does the chimney swift eat?
Chimney swifts eat flying insects that they catch in flight. Some of their common prey includes:
- Flies
- Beetles
- Moths
- Ants
- Wasps
- Dragonflies
Chimney swifts forage for insects high in the air, sometimes at heights over 1,000 feet. They drink by skimming the surface of water bodies and catch flying insects at the same time.
How do chimney swifts nest and roost?
One of the chimney swift’s defining behaviors is its habit of nesting and roosting inside narrow, vertical spaces such as chimneys. This is reflected in some of its other common names like chimney sweep or chimney topper. Features that chimney swifts use for nesting and roosting include:
- Brick and stone chimneys
- Hollow trees
- Wells
- Silos
- Vents
- Caves
Nests are made by the birds gluing together small twigs into a shallow bracket shape using their saliva as adhesive. The nest is attached to the vertical surface. Chimney swifts may return to the same nesting site for years.
At night, chimney swifts roost communally in large numbers, sometimes with thousands of birds packed into one chimney or structure. It is thought the communal roosting helps conserve body heat.
How do chimney swifts fly and migrate?
The chimney swift is specially adapted for fast, agile flight to catch insects.
Features that aid its flying ability include:
- Long, curved wings
- Short, stiff tail feathers acting as a rudder
- Small feet set far back on the body
- Large chest muscles for power
Chimney swifts beat their wings very rapidly, up to 200 times per second! This allows them to make quick maneuvers in pursuit of insects. Chimney swifts spend almost their entire lives flying and are very awkward when perched or walking.
For migration, chimney swifts fly during the day, feeding as they go. At night, they descend and roost communally before setting off again the next day. Their migrations can cover thousands of miles between their breeding and wintering grounds.
How do chimney swifts communicate?
Chimney swifts have various vocalizations used for communication. Some of the most common calls include:
- High-pitched twitters between mates at the nest
- Loud screeching or chip notes in communal roosts
- A mechanical ticking sound during courtship
- Begging calls by nestlings
These vocalizations allow chimney swifts to communicate within pairs or groups. The sounds can alert others to food sources or signal distress.
What is the chimney swift’s conservation status?
Chimney swift populations have undergone significant declines in recent decades. Habitat loss is the major threat facing this species. Some key factors in the chimney swift decline include:
- Loss of old, large chimneys as modern construction changes
- Loss of hollow trees in mature forests
- Pesticide use reducing insect prey abundance
- Climate change disrupting migration and breeding
Due to these threats, the chimney swift is classified as Near Threatened by the IUCN Red List. Ongoing conservation efforts aim to provide artificial nesting sites and protect key roosting and foraging areas.
Interesting chimney swift facts
- Chimney swifts spend almost their entire lives flying. They even mate while flying!
- A group of chimney swifts circling in flight is called a “kettle.”
- Chimney swifts fly from Canada all the way to the Amazon basin to overwinter.
- Chimney swifts eat up to 1/3 of their body weight in insects daily.
- The oldest recorded chimney swift was over 12 years old.
- Chimney swift numbers have declined by over 70% since the 1960s.
| Location | Population Trend |
|---|---|
| Eastern USA | Declining |
| Midwest USA | Stable |
| Western USA | Increasing |
Conclusion
In summary, chimney swifts are remarkable birds uniquely adapted for aerial living. Their use of chimneys and other structures makes them dependent on humans to some degree. Conservation efforts to provide nesting sites and protect their food sources can help the chimney swift thrive once again.
