Thousands of migratory birds were killed or injured after apparently mistaking a Wal-Mart parking lot, football fields and other snow-covered areas of southern Utah for bodies of water and plummeting to the ground in what one state wildlife expert called the worst mass bird crash she'd ever seen.
Crews went to work cleaning up the dead birds and rescuing the injured survivors after the creatures crash-landed in the St. George area Monday night.
By midday Wednesday, volunteers had helped rescue more than 3,000 birds, releasing them into a nearby pond. There's no count on how many died, although officials estimate it's upwards of 1,500.
"They're just everywhere," said Teresa Griffin, wildlife program manager for the Utah Division of Wildlife Resource's southern region. "It's been nonstop. All our employees are driving around picking them up, and we've got so many people coming to our office and dropping them off."
No human injuries or property damage have been reported.
Officials say stormy conditions probably confused the flock of eared grebes, a duck-like aquatic bird likely making its way to the Mexican coast for the winter.
The birds plunged into a Cedar City Wal-Mart parking lot, football fields, highways and over miles of property that had been blanketed by about 3 inches of gleaming snow.
"The storm clouds over the top of the city lights made it look like a nice, flat body of water. All the conditions were right," Griffin told The Spectrum newspaper in St. George (http://bit.ly/rYpQbJ). "So the birds landed to rest, but ended up slamming into the pavement."
Kevin McGowan, who studies birds at the Cornell Lab of Ornithology in Ithaca, N.Y., said grebes rely on starlight to navigate during their nighttime migration.
"Before there were (artificial lights), the sky was always paler than the ground," he told The Associated Press. "When all of a sudden there's light all over the place, they don't know which way is up anymore."
McGowan said it's not uncommon for birds to crash en masse, especially if they confuse the ground for water.
A high-profile crash in Arkansas in January killed about 4,500 birds, mainly red-winged blackbirds. The National Wildlife Heath Center concluded the birds were startled by loud noises in the area, including celebratory fireworks on New Year's Eve, and crashed amid their poor night-vision.
More than 175 mass death events, in which more than 1,000 birds died, have been reported to the National Wildlife Heath Center in the past 10 years. Causes for those die-offs included disease, weather, poisoning, trauma and starvation.
But Griffin said the Utah downing was notable among the ones she's seen because it was so widespread. Downed flocks were reported all over Cedar City, and as far as 30 miles south.
"I've been here 15 years, and this was the worst downing I've seen," she told the newspaper.
Wildlife officials said they were continuing the rescue effort that started Tuesday afternoon and included residents collecting grebes _ which weigh about a pound _ and delivering them in cardboard boxes to the wildlife department's office.
Officers said once they dropped the birds into bodies of water in southern Utah's Washington County, including a pond near Hurricane, the water-loving creatures were "very active."
Many of the birds had broken wings or other injuries from the accident. Wildlife agency spokesman Lynn Chamberlain said the birds' hollow bones can heal, although humans can't do much to help the process.
Keeping them in water _ where they have food and won't have to fly _ improves their chances.
"We're giving them the best shot they can," Chamberlain said. "The likelihood is that most of them will survive."