Buddy Brown lifts his weapon, a "golden eagle" thermal fogger, and begins a slow walk beneath the shadows of the Bradford pear trees on the 12th Street side of The Chattanoogan hotel.
With dusk settling, the trees are alive with squawks and flutters of migrating black starlings -- sturnus vulgaris -- autumn's No. 1 nuisance bird in the Southeast. Droppings fall like rain from these urban flockers, which can number in the thousands.
Brown pushes a button and the "golden eagle" belches a momentary three-inch flame and chokes out a clatter that easily competes with the squawks of hundreds of starlings. He aims the smoker into the bottom limbs of the pear trees, and a grayish haze boils up into the branches, filling the street with a burned-bubblegum smell.
By the scores, starlings take flight -- screeching high into the air before settling again in another row of trees half a block away on Chestnut Street.
"I'll make several passes here until it gets dark," said Brown, a city public works employee of 33 years. "Eventually the birds will know to stay away from these trees -- till the next migration."
The poop-and-squawk of spring and autumn starlings has businesses calling the city, asking for some help from the droppings and the noise. So city workers dutifully trot out the foggers, trying to convince the birds that there are more comfortable places to roost.
The seasonal quandary of dealing with the birds in the Environmental City is not new. In 2005, city officials hired a Fort Wayne, Ind., company to gas the birds with what was billed as a "grape-bubblegum-scented" fogger. Cost: $7,000.
Now city workers like Brown do the work, using equipment and methyl anthranilate -- concord grape extract -- bought from the Fort Wayne company, Flockfighters.
Generally recognized as safe, the methyl anthranilate is used as a food flavoring and fragrance additive. It also has been found to be an effective and EPA-approved bird repellent.
But the fogger control method still is taking some of the city's wingless residents by surprise.
What's in the fogger?
Methyl anthranilate, a naturally occurring compound found in flowers and in grapes.
How does it work?
It repels the birds by painfully stimulating the nerves in their beaks, eyes and throats.
What about other animals?
Only birds react to methyl anthranilate. Other animals sense a pleasant grape scent.
Source: Flockfighters.com, U.S. Environmental Protection Agency
Earlier this week, fire engines screeched up to the stand of fogged trees when evening workers in the Tennessee Valley Authority building next door reported a caustic smoke in their ventilation system and in the street.
"We need to do a better job of community education about the project," city Forester Gene Hyde said.
"But the fog is completely harmless -- to us and the birds," Hyde said. "Eventually they learn to associate that pain (in their beaks) to those trees where we spray, and they'll stay away from them."
Downtown worker Janet Watts was less enthusiastic when she left work Tuesday to find she couldn't get to her car until the smoke cleared.
"I can't believe this would be good for your lungs," she said.
Lance Dorsey, director of facilities at The Chattanoogan, said he asked the city to fog the trees because the thousands of starlings had become "a guest issue" with the amount of their droppings on 12th Street and in the hotel's courtyard.
The city's earth-friendly effort is helping, he said, except for one thing.
"The only problem is that now they've pushed everything (the bird roosting activity) to our center courtyard."
Because the courtyard is hotel property -- making it a hotel problem -- Dorsey says he's "looking to hire somebody to spray it."
The city can only take care of the public sidewalks and parks, according to city officials.
"You have to see it out here to believe it," Dorsey said. "Every morning it looks like the old Alfred Hitchcock movie ["The Birds," 1963]."