Chimney Sweeps flit fast in the Piney Woods
Jay V. Huner
Folks new to homes with fire places sometimes hear an odd scratching sound in the spring of the year. What's making the sound? Often the source is made by newly arrived Chimney Swifts examining the uncovered chimney as a roosting site or a place to nest. But, because most chimneys are covered with mesh to keep critters out, few now experience visiting or nesting Chimney Swifts.
Before Europeans came to the New World, there were no chimneys for Chimney Swift habitat. These small, dark gray, almost black birds are often referred to as flying cigars nested and roosted in hollow trees and caves. However, they adapted quickly to chimneys, hence the colloquial names "chimney sweeps" or "chimney swifts".
Chimney Swifts somewhat resemble swallows in shape and behavior. Length is a bit over 5 inches and wing span is roughly 14 inches. Unlike swallows, Chimney Swifts have narrow, curved wings and cigar-shaped bodies. Swallows are also far more colorful.
Chimney Swifts have very small legs and feet so they cannot perch like other birds. They use the claws on their four-toed feet to cling to the vertical sides of chimneys, hollow trees and caves. The shafts of their tail feathers extend beyond the end of their tails. This enhances their ability to hold tight.
When the swifts leave their resting/nesting places, they fly continually. They bathe on the wing, slapping their bodies against water surfaces. They collect twigs for their nests by flying into branches and grabbing them with their bills. Some believe they can even sleep while flying on long distance migratory journeys. While some swifts mate on the wing, Chimney Swifts apparently mate in their roosting/nesting places.
Chimney Swifts are not songsters. They have a high pitched twittering call which they are almost always making when flying about in search of food.
Chimney Swifts have very tiny bills but huge mouths. They feed almost exclusively on flying insects and spiders that disperse by spinning a long thread that catches the wind carrying them along. One report, however, suggests that the swifts may pick off berries as they fly by berry covered plants.
Chimney Swifts have unique mating behavior. A pair flies about and from time to time holds their wings in a vertical "vee" and glide together.
Chimney Swifts build their nests on the sides of vertical surfaces. They use glue-like saliva to hold twigs together. In fact, oriental bird nest soup is made by boiling the nests of one species of Asian swift. Once the eggs have hatched, parent swifts use the saliva to form balls (or boli) of insects and spiders and then feed them to the hatchlings.
How many Chimney Swifts can you put into a chimney or large hollow tree? Well, several thousand have been found roosting in such habitats. However, you'll only find one nesting pair in a chimney or hollow tree.
When swifts are leaving or returning to a large communal roost, they create quite a sight. Some refer to these mass coming and goings as "swift tornadoes".
There is concern about the conservation status of Chimney Swifts because there are not so many chimneys any more when compared to past times. And, many chimneys are capped to prevent swifts and other animals from getting into them. You can actually build a Chimney Swift Tower. Information about these swift habitats can be obtained from the Chimney Swift Conservation Association.
Chimney Swifts arrive in the Piney Woods in March and leave by October. If you happen to see a swift at any other time, it's likely to be a rare Vaux's Swift, a stray from west of the Rocky Mountains.