MODESTO -- Look, up in the sky. It's a bird. It's another bird. It's whoa, that's a lot of birds.
The sky above downtown Modesto has been filled with birds, a lot of birds, at sunset each night for months. The birds in question are starlings, a European species common across the country and around the world.
The glossy black birds have been returning to roost in downtown Modesto's trees, towers and tops of buildings for the past few years. And their numbers appear to be growing by the thousands.
Part of the flocks' nighttime ritual is an elaborate twilight dance, a phenomenon known as murmuration. The birds swoop and swirl in the air in unison, creating a moving black cloud above the city skyline, before finally roosting for the night.
Christopher Hull, manager at downtown Modesto's Galletto Ristorante, said he has seen the flock return to the area year after year with amazement.
"Five years ago, I saw a little," Hull said. "Four years ago, a tree or two was full. Three years ago, half the trees were full. Last year, it was worse. This year, it's insanity. Every tree in our area was shivering with birds. I can't wait for next year. It's pretty amazing to watch. Unfortunately, you don't want to be under it."
The aerial acrobatics may be amazing to watch, but for those on the ground, it poses unpleasant problems. Because what goes up must have stuff that comes down in this case, bird droppings.
Andy Johnson, maintenance director for the city and county headquarters at Tenth Street Place, calls the starlings his "archenemy." His task of keeping the buildings and plaza clean has gone to the birds, quite literally.
War against droppings
Since October, the city has had to pressure-wash the plaza every morning to remove the droppings left by the roosting birds. The power cleaning at 5 to 6 a.m. each day, before the offices and shops open, cost the city $1,000 a week until it stopped in early December.
"When you're first driving around and see them, you might think, 'Oh, that's so amazing,' " Johnson said. "But when they are here every day and their droppings are here every day, it's quite frustrating. You have no more sense of how beautiful they are. Downtown Modesto is not where we want them."
Large flocks of roosting starlings are no strangers to urban environments. They have created headaches in cities from Boston to Cincinnati to Seattle. Throughout the fall and winter, flocks have been spotted in other areas of Modesto.
California State University, Stanislaus, zoology Professor Ann Kohlhaas said the birds are known to be a gregarious species that roosts in large, dense flocks, especially in the winter. Their numbers can swell to the tens of thousands, with some flocks reported as large as 100,000.
Kohlhaas said the reasons for the birds' murmurations aren't known. She said the fanciful flight could be done because of worries about predators or just to settle down from the day.
How they perform their coordinated flights is not known either.
"Probably if you're watching the bird next to you, if it goes one way, you go one way, and so on," Kohlhaas said. "And if you're in a large group, you are unlikely to be picked off."
How they got to the United States, however, is known. Starlings were introduced to North America in 1890, by William Shakespeare enthusiasts who thought all animals mentioned in the bard's works should be present across the pond. After a few attempts, those 100 birds released in Central Park turned into the 200 million starlings in the country today.
Kathryn Purcell, a research wildlife biologist with the U.S. Forest Service, said starlings are omnivorous, eating insects, fruits, grains, seeds and whatever other food they can forage. As a nonnative species, they are often seen as urban and agricultural pests. They feed in smaller flocks during the day and come together in larger groups at night often from 30 or more miles away.
"They've done very well in the Central Valley in general," Purcell said. "They're extremely successful, way too successful. They're very hardy and very adaptable and very intelligent. We're never going to control them. They are here to stay."
The winter flocks frequently grow in size because birds communicate with each other when they find a successful roosting area, she said.
In Modesto, roosting flocks have been spotted in several places, from near Marie Callender's at Coffee Road and Sylvan Avenue to near Memorial Medical Center on Briggsmore Avenue to the Save Mart center at Oakdale Road and Scenic Drive. The downtown Modesto flock has spread itself along several blocks Tenth Street Place, Brenden Theatres, the DoubleTree hotel, radio towers and sidewalk trees.
Since October, when the birds arrived, downtown business owners have been talking about the swarm. The birds' presence, with their noise and droppings, has alternately awed and annoyed patrons in the area. The Downtown Improvement District has discussed the birds and plans to do so again in the new year.
Moviegoers who camped out in front of Brenden Theatres in mid-November to see the highly anticipated release of "The Twilight Saga: Breaking Dawn Part 2" brought umbrellas, but not for the rain.
Brenden General Manager Saul Trujillo said his customers have asked about the birds, which have roosted this season in the trees in the plaza and in the neon tower on the building's roof.
"A lot of them ask why I don't do anything about the birds outside," he said. "And I say I'm sorry you don't like the birds, but there's nothing we can do as a business. We've discussed it with the Downtown Improvement District, and the best we can do is make sure downtown stays as clean as possible."
The cleanliness factor is not just so customers and employees don't have to wash their cars daily from a deluge of bird droppings, but also because the waste can cause an infection called histoplasmosis. The disease is caused by breathing in fungi often found in bird and bat droppings.
Tenth Street Place maintenance director Johnson said he's tried a number of approaches to get rid of the birds, which are not a protected species, and the mess they leave behind. He's used deodorizers for the smell, along with the daily power washing. This year, the city used squawk boxes, sonic emitters that send out a danger signal for birds, and fake owls. In the past, the city has used netting to keep them out of areas, but that was abandoned because birds became trapped.
"We tried the squawk box that signals 'Danger! Danger! Danger!' " Johnson said. "That lasted a day before they realized there was no danger. We tried a fake owl. That lasted a day before they realized he was fake and pooped on him, too. I've read some airports use propane cannons, which send off a boom every two minutes. But, yeah, we can't do that downtown."
Falcons 'on speed dial'
Later in the season, Johnson said, he contacted several falcon groups that said they could relocate flocks using the birds of prey. He said if the swarm returns next year, he has those numbers "on speed dial."
What has helped is pruning the trees. In mid-November, the city trimmed the 10 trees in the plaza, which had been thick with roosting starlings sitting side by side on almost every available branch. The weight of the birds had broken off 10-inch sections, and Johnson said he feared they'd cause a safety hazard with falling branches or kill the trees.
The trimming helped, but what helps most is time. The birds are still on their migration pattern, and as the weather gets colder, they will move on to warmer locales. Last year, they left after Thanksgiving, but this year they've held on longer, Johnson said.
Still, the flock is thinning and is expected to be gone soon.
"We can't wait," Johnson said. "I know they are beautiful and they make nice patterns, but they are definitely a nuisance. I'm studying my enemy now, to be ready if they come back next year."
Bee staff writer Marijke Rowland can be reached at email@example.com or (209) 578-2284. Follow her on www.twitter.com/turlocknow.