A bird in the hand.

What do 19 states and four Canadian provinces have in common? Hint: It's worth money in the bank. Answer: Birding festivals.

States and communities are promoting their feathered friends, hoping to attract bird watchers and their money. Birders will flock to places where they can see birds that are either unique or migrating in great numbers. Birders, who tend to be affluent, make significant contributions to the economy. They have to eat, sleep, buy gas or pay for other means of transportation, and they buy extraordinary quantities of film. They pay for special excursions into the Louisiana swamps and the Gulf Coast of Texas.

In Texas, with 600 species of birds, studies have shown that tourism is a $23 billion business, likely to outstrip oil and gas and agriculture by the next century. Hunting and fishing and wildlife recreation brought in $3.6 billion in 1993. The economic impact of birdwatchers along the upper Texas coast was estimated at $4 million to $6 million in 1992. One small bird, the yellow-green vireo alone is thought to bring in at least $100,000 per year. (Yes, avid birders will get on a plane to see just one bird for their life list.) Nebraska's sandhill cranes brought in an estimated $1.26 million in 1991, a figure that is increasing by 20 percent a year, according to the state magazine Nebraskaland.

What do states do to attract birders? Texas heads the list for the most birding festivals and also has an official birding trail. In Arizona there's a hot line to call if you are looking for a special bird for your life list. Local and county governments in Mississippi have set aside stretches of beautiful beach and built viewing platforms for the public so terns can nest unmolested. Nebraska protects and maintains its Platte River habitat where 80 percent of the continent's cranes come to fatten up each spring for the flight to the Arctic. On the Platte, birders can find fossil cranes and their living descendants, 500,000 of them taking off in wave after wave in the morning sunrise from their evening roosts. "They're fun to hear, they don't damage the crops, and their arrival is an annual occasion," says Nebraska Senator Ed Schrock.

Different locations of course have individual attractions. High Island, Texas (6,000 bird watchers and $2.5 million in 1992), may be appreciated most by birders who want to sit and watch or who need time to look at their books and to take a second look. The birds are so tired from flying over the Gulf of Mexico in the spring migration that they simply perch and rest once they make land. Arizona is famous for its hummingbirds. California celebrates Duck Days with field trips, bike trips, workshops and even a game bird barbecue. Nesting bald eagles are viewable in Washington, and the hawks soaring on the thermals over Cape May, N.J., bring thousands of watchers and hawk counters.

The Texas Legislature has helped the Texas Parks and Wildlife Department promote the Great Texas Coastal Birding Trail, which will be 500 miles long with 50 significant stops. "Eco-tourism is an important economic development tool," says Texas Representative Clyde Alexander. "It provides economic possibilities in our own backyards and forces us to take care of our surroundings for future generations to enjoy."