ATHENS, La. (KTAL/KMSS) - During September, a few waterfowl species, like Blue-winged Teal, will begin to make their way into the Bayou State for the winter, along with tons of shorebirds. Most migratory bird species that nest in the state will begin their yearly fall exodus, with most heading to Central or South America. And one of the coolest fall migration phenomena we can experience in Louisiana is that of the Chimney Swift, Chaetura pelagica.

The Chimney Swift is a bird many of you know. Commonly but erroneously referred to in the South as "Chimney Sweeps," Chimney Swifts do live in chimneys. There, they spy on you and drink your milk when you leave the house.

But you might ask, "What did they do before chimneys?" And were they just called "Swifts" then? Regardless of what they were then, they nested in hollow trees or caves, but they soon began adapting to chimneys after European colonization. We know of chimney nesting records as early as 1672, and by the 1790s, Chimney Swifts were almost exclusively nesting in chimneys.

Chimney Swifts are admittedly drably colored, but they're honestly pretty adorable. Birders often describe them as "cigars with wings," which is pretty accurate. But there's more to them than the odd moniker. First, they have fangs. Okay, so they don't really have fangs, but they are really, really fast. It's almost as if there's a connection there with their name.

And speaking of their name, there's a lot going on there, too. The name of the taxonomic family swifts belong to is Apodidae, which means "without feet." And before you ask the next obvious question, yes, they have feet. But their feet are ridiculously small. In fact, they're so small that chimney Swifts can't walk or perch on limbs or utility lines or wear shoes.

What does that mean for them, then? It means they spend almost their entire lives in the air. They eat and drink from the air. They can even mate in the air, especially if they fly by a picnic and someone's playing Barry White songs. Their tiny feet allow them to cling to the interior walls of chimneys or hollow trees or sometimes to the sides of buildings. But their feet are still so tiny that Chimney Swifts still need help to hold up their bodies that weigh less than one ounce. Their genus name, Chaetura, means "bristle tail" because each tail feather's very stiff, central shaft extends beyond the feather tips, and the birds use them to prop themselves when clinging to a vertical surface. You can see them in the photo of the bird in hand.

One of the cutest traits of Chimney Swifts is their voice. As they zoom by, you'll often hear them emit a high-pitched, squeaky twitter. Think of a squeaky grocery cart wheel, but revved up to about 60 miles an hour. However, if you approach a nest, the hatchlings emit a vocalization that sounds like a group of cicadas suffering demonic possession.

You might also wonder what their nests are like since they nest inside buildings. The swifts break off small pieces of twigs with their tiny bills because their feet are too small and weak to do so (www.birdsoftheworld.org). Then, they take them one by one inside their chosen chimney and use duct tape to slowly create a sort of half-funnel-shaped nest against the wall. Okay, fine. They don't use duct tape.

But you're not gonna like what they really do. They actually use their saliva, which becomes extra sticky like glue during the nesting season. And that is one bird trait I can personally go without.

If you want to see swifts nesting up close and personal, you can find plans online to build your own Chimney Swift nest tower and install cameras to spy on them. The towers are generally about 12-15 feet tall and look like a chimney sitting in your yard.

So, what's the benefit of building a Chimney Swift tower? For one, Chimney Swifts are a "species in decline." The North American Breeding Bird Survey shows a decline of about 67% between 1966 and 2019. In human equivalency, that's like taking the current population of the United States and losing every single person except those in California, Florida, New York, and Texas. Chimney Swifts aren't listed as Endangered, but these numbers are no joke. If you have a chimney, please leave it open, and don't bother the swifts, especially since they're protected under federal law. Wanna guess the main reason for their decline? Central heating.

If you're lucky enough to live near older buildings with large chimneys or factory smokestacks, September is the time of year in Louisiana to witness one of the coolest fall migration events in the bird world: Chimney Swift tornados. In the half-hour or so before sunset, Chimney Swifts that are in the process of migrating South will create large swarms and circle their intended roost site. It's common to find hundreds or even thousands of swifts within the swirling, aerial eddy. In my home parish of Claiborne, some friends and I once watched a swarm of 1100 Chimney Swifts enter into a large chimney of a local school.

This natural event has led to the creation of an annual Chimney Swift count called "A Swift Night Out" which is sponsored by the Chimney Swift Conservation Association. During the second weekend of August and of September, you can count the number of swifts that enter roosting chimneys and enter your data into www.ebird.org, the largest online database of bird sightings in the world. But honestly, you can do this any night of the month. Bring the bug spray and some cold drinks, find a shady spot, sit back and count the birds only when they enter the roost, and then report the numbers. It'll be the easiest conservation work you do all year!

John Dillon is an expert on bird identification. He teaches at Minden High School, has served on the Louisiana Bird Records Committee since 2011, and is a past president of Louisiana Ornithological Society. Dillon is also a regional reviewer for Cornell University's www.ebird.org, the largest online database of avian records.

For content-related questions, email John Dillon at merlin183@yahoo.com.