In many parts of California's Sacramento Valley, hearing the high-pitched cries of newborn blackbirds was once a common occurrence.
"It's something that I hear very infrequently, almost rarely anymore," said ecologist Bob Meese.
Meese has spent the last decade studying the tri-colored blackbird, which once numbered in the millions.
The decline, Meese says, is unprecedented based on surveys coordinated by him and his team at the University of California, Davis.
In 2008, the state was home to 400,000 tri-colored blackbirds. Today, there are only 145,000 - a 64 percent loss in just six years.
"There are parts of the state where the birds seem to be disappearing altogether," Meese said.
Meese is now catching the birds so he can tag them and track their movements. He believes the birds' natural habitats are being increasingly turned into farmland and vineyards, which rely on pesticides that kill off the very insects they feast on.
"If they do not have enough insects in their diet, they simply cannot form eggs," Meese said.
So Meese is trying to convince growers to give up pesticides
"The blackbirds could act as a natural insecticide," Meese said. "If we can reproduce this specific set of circumstances in enough places in California, I think the species has a future here."
Unless that idea takes flight, Meese says, this iconic bird could be lost forever.