Just before sunset in a hotel parking lot in west Wichita, Bob and Nancy Livingston are prepping for what looks like a mini tailgate party. Bob Livingston hops up onto the gate of his pickup, and Nancy sets out a lawn chair.
Then they look toward the sky, and wait.
"We come every year," Nancy Livingston said. "It's just amazing seeing all these birds, and we are purple martin landlords."
In their backyard in Derby, the Livingstons have eight hollowed-out gourds and a 12-room birdhouse where purple martins build nests every spring.
Purple martins are a type of swallow known for their aerial acrobatics and rich chattering songs. Bob Livingston says they’re also great bug catchers.
"Our neighbors love them. We have them because they eat mosquitos. ... They They pick them out of the air," he said. "So for about two or three houses around us, people don’t have mosquitos in the summertime. ... Plus, they sing every morning and every night.”
The Livingstons have hosted the birds for about 15 years. They figure their Purple Martin Airbnb produced about 90 hatchlings this year.
But now it’s late summer, and it's almost like birds throughout the region got a memo to head to the airport.
After leaving their nesting colonies, purple martins gather in large flocks to feed, socialize and rest before their annual migration to Brazil. As part of this season's pre-migratory roosting, the purple martins are putting on a nightly show near the Wichita airport control tower, gathering in a cluster of trees near Yingling Aviation.
The birds form large communal roosts in urban areas because ambient city heat and light can deter predators like hawks and owls. The birds feed on flying insects to build fat reserves for their long flight south.
The nightly event begins quietly. Around 8:30 p.m., the sky is almost clear. One by one, and then dozen by dozen, the birds start arriving from all directions. Within 10 or 15 minutes, thousands of birds converge into a massive cloud that swirls and twirls overhead.
Witnessing the migration sometimes requires a little research. Because roosting sites can change from year to year, bird watchers post notices online when they start to see the martins gathering.
In years past, Wichita-area birds have roosted in Old Town, near Via Christi St. Francis Hospital, and near the former Palace Theater on East Kellogg.
Lisa Vayda drove around for nearly half-an-hour looking for this year’s location. After checking last year’s spot near Hoover Road, she said, she looped around closer to the airport.
"It was too dark to see, but as we drove by here, you could just hear it,” she said.
You can definitely hear it. By 9 p.m., tens of thousands of birds flap in tornado-like formations overhead. If you look up, they look like schools of fish swimming in an ocean — or like something from a Hitchcock film.
When thousands of birds lift off together around sunrise, they can even be seen on Doppler weather radar, creating a distinct circular pattern known as a "roost ring."
Because this year’s roosting spot is so close to the airport, officials say they are tracking the purple martins as part of a wildlife hazard management plan required by the Federal Aviation Administration. Emergency vehicles sound occasional sirens so the birds "do not hang around the airport and cause possible issues for aircraft," said Roger Xanders with the Wichita Airport Authority.
Vayda said the annual spectacle is magical.
"The way that they’re able to communicate, to organize this, and how they decide to do it, how they decide where to go," she said. "It’s one of the true amazing wonders of nature.”
By 9:15 p.m., most of the birds cluster in the trees and begin to settle down for the night, and the skies are clear. In Wichita, the purple martin migration usually peaks in early to mid-August but can continue through the month.
Nancy Livingston said the migration is bittersweet.
“It’s kinda sad, because we won’t hear their chatter anymore," she said. "The neighbors always ask, ‘When are they coming? When are they coming?’ Because they sit out on their porch also and look forward to listen to their chatter."
