(CBS News) With summer winding down, millions of migratory birds are on the move. But his year, things are a bit different, especially for tiny hummingbirds. Drought and climate change have shifted the landscape dramatically.
Some hummingbird species fly 2,000 miles during migration. And with a heart rate of up to 1,200 beats per minutes, they often need to eat five times their body weight, every day.
This year's migration is complicated by the lack of natural wildflowers, which have been hit hard by drought and forest fires.
So birds that are looking about for their usual food sources are heading elsewhere. Large numbers of birds are swarming feeding stations set up in gardens and backyards in drought areas out West.
It is standing room only at many feeders -- and that has hummingbird fans buzzing.
"I'm speechless, really," said one woman who has set up feeders for the hummingbirds, "to just sit here and be so close that I can see them."
Lenore Hemingway is being especially careful to keep her 20 feeders filled with sugar water at her home in Sedona, Ariz.
"You make sure that they have all of the things they need," she said. "They have the sugar feeders, which they do rely on on their migration. They have all of the flowers they love."
"It is a commitment," she added. "But the joy is getting to view them."
No one's quite sure how the drought will affect hummingbird populations in the short term.
Biologists are more concerned about the long-term effect of climate change. Fewer wildflowers means fewer sources of nectar along migration routes.For more information:
Cornell Lab of Ornithology
PRBO Conservation Science
Ross Hawkins founded the Hummingbird Society.
"There is a chance in the future that there will be significant problems with certain species -- where the birds find less of the sources of food than they found in years before," he said.
In difficult seasons like this, backyards can be welcome rest stops on the winged migration. And Lenore Hemingway is glad to lend a hand.
"To just see the beauty of the birds, the coloring," she said. "They're just amazing. "
Amazingly small, but, also amazingly adaptable.