KAYSVILLE — In the bird world, females don't dress up for a date.

They let the males primp and preen.

On a recent Saturday, red-winged blackbirds were flashing feathers and singing songs as they swooped across ponds near the Utah State University Botanical Center in Kaysville.

There were killdeers, gulls and an Audubon's warbler. Mallards and Canada geese swam past a double-crested cormorant. A red-winged blackbird chased an American crow away from its nest.

It's that time of year when the birds are active: The males are displaying colorful plumage — and singing for attention or love.

"The guy only sings for two purposes," said Bill Fenimore, a birding expert and owner of the Layton Wild Bird Center. "They sing to tell the other males, 'Don't come here, it's my territory,' or to let the girls know he'd like to have them visit."

Those antics and others are what draw thousands to the sport of birding each year.

One out of five Americans is a birdwatcher, according to a 2001 report from the U.S. Fish and Wildlife Service. It's the nation's fastest-growing hobby and the second most popular. Gardening is first.

Birders spent $32 billion in 2001 for travel, food and gear. More than 863,000 jobs were supported by this output.

"It is a multibillion-dollar industry in just seed sales alone," said Fenimore.

In Utah, birders and other "non-consumptives" far outnumber the state's hunters and anglers. Because of the Great Salt Lake — part of the Western Hemispheric Shorebird Reserve Network — people from around the world recognize Utah as a prime birdwatching destination.

On Thursday, about 4,000 will converge in Davis County for the 7th annual Great Salt Lake Bird Festival. It's the peak migration time, when millions of migratory waterfowl will rest, eat brine shrimp and brine flies and prepare for a journey north.

For the past year, volunteers have been preparing displays and arranging birding trips across northern Utah. It's one of Davis County's largest tourist events, bringing the area about $160,000 last year.

This year is expected to be better, said Neka Roundy with Davis County Tourism.

"We've always had a quality project," she said. "Programming has been excellent and remained excellent. It's tied to the tourism trend, and people are feeling better about traveling; feeling better about being here — about us."

Seven years ago, the bird festival had a budget of zero and little recognition. It was three days long, and former Gov. Mike Leavitt was the keynote speaker.