The season of swifts

It’s September, and the skies above downtown Raleigh are again graced at sunset with the gathering of chimney swifts chippering aloud as they search for a place to sleep – their nighttime roost. If you haven’t witnessed the spectacle of these birds swirling above a chimney, now is the time.

Swifts return downtown each evening from now until early October when they migrate south. Their vocalizations and swirling signal “vacancy” for those arriving from places farther north. It takes a full 20 to 30 minutes for a swirl of 4,000 swifts to enter a chimney. Forget the wildebeest migration across the Serengeti. This is great, free seasonal entertainment right here in our urban core!

Sadly, they’ll find fewer options this year. Two roosts at the Dillon Supply warehouse were razed. Neither Kane Realty nor the Railroad Terminal architects were able to save their chimneys. This year’s roost, in The News and Observer’s own chimney, is slated to be demolished. Wake Schools have lost dozens over the last decade: Broughton High School; Martin, Daniels and Ligon middle schools; Lacey, Washington, Underwood, Conn and Wiley elementaries, among others. Hunter recently capped its chimney, sacrificing a roost of 1,000 swifts.

All is not lost. A roost at the Stone’s Warehouse will survive – the developers recognize it as a seasonal attraction. Lincoln Height’s Elementary PTA in Knightdale is fighting to keep its roost chimney during redevelopment. They recognize the extraordinary educational opportunities inherent with a species that has adapted to live with people.

Chimney swifts are typically social. They feed in flocks on emerging winged termites and ants and on midges and mosquitoes over lakes. Their family, “Apodidae,” means “without feet” – referencing the fact they cannot walk, hop or perch. They cling to vertical surfaces while nesting or sleeping. Once they take flight in the morning, they fly nonstop all day. They feed, drink, bathe and court in flight!

Swifts arrive in North Carolina in April to nest – one pair per chimney. Prior to European settlement, they used hollow trees, but now they depend on humans. They use sticky saliva to glue twigs to a chimney wall when nesting. By August the young join their parents flying above our neighborhoods and begin to roost in large industrial chimneys.

In the 1930s birdwatchers became curious about swift migration. The U.S. Fish and Wildlife Service had success using bird bands to track the movements of waterfowl. Why not try them on swifts? Well, no money. No matter! Dozens volunteered to do the work. Over a 22-year period, folks in Canada, New York, Ohio, Georgia and Tennessee organized an incredible effort. They climbed atop buildings at night and up extension ladders to install cages atop the roost chimneys. As the birds emerged in the morning, they were captured. In total, over 550,000 were banded! The story made the cover of Life Magazine.

We learned that swifts used the same roost chimneys year after year. Families appeared to migrate together. Birds banded in Ohio turned up later in Georgia. Finally, in 1944, 13 bands arrived at the Fish and Wildlife Service – postmark: Lima, Peru. How were they recovered? Amazonian Indians near Iquitos found the bands on swifts they had smoked out of a hollow tree so they could eat them. Imagine the discussion of the tribal elders! The bands were taken to the Jesuit mission and sent home. Swifts have extraordinary physical and behavioral adaptations and a storied history with humans. Is it any wonder the Lincoln Heights PTA wants to incorporate swifts into its STEM curriculum?

Raleigh’s chimney swifts are the most video-taped flock in the world. Our birds have appeared on Exploring North Carolina and on a National Geographic program. Recently, scientists from UNC-CH used video to study aerial dynamics within the flock as it dealt with wind, thermals, buildings and flock-mates while traveling at high speeds. The project transformed mathematicians and students of physics into birdwatchers. By project’s end, computer simulations offered a swift’s eye view of the buildings of downtown Raleigh as if the viewer were part of the flock. Incredible!

Unfortunately, swifts are losing their roosts in Raleigh, and we are losing the opportunity to watch them. It’s time for city and county leaders to convene a swift task force. We should save what we have and design more. Maybe a roost as an artistic structure, or a complement to a development. Maybe at Dix Park? But somewhere, before it is too late!

This story was originally published September 24, 2016 at 6:00 PM with the headline "The season of swifts."