MANKATO — From a handful of people eight years ago, the Great Minnesota River Birding Day scheduled for Saturday has grown to more than a hundred participants.

All are birders of varying ability and experience, and all are welcome to participate, says event organizer Bob Williams.

Sponsored by Audubon Minnesota, the day is to count the number of species seen or heard along the length of the Minnesota River. (The Audubon Christmas count, also done in the area, tallies the number of species seen and the number of beaks spotted in one day.)

Last year was a record day for the Great Day, with 204 species recorded. Williams doesn’t expect to best that this year, but it depends on a lot of factors, such as the weather and the number of teams or individuals participating.

Williams hopes there will be up to 115 people participating again this year. He says many teams form around the Mankato area, but out west the event gets one or two people birding any given area.

Chad Heins, biology professor at Bethany Lutheran College and president-elect of the Mankato Bird Club, takes a group each year to the Kasota Prairie loop of the Minnesota River Valley Birding Trail for the Great Day.

“If I don’t hit a hundred (species), I’ll be pretty sad,” Heins says of his expectations of the event. He has led a team of birders in the prairies north of Mankato for three or four years.

Although like most dedicated birders, Heins says he has no favorite bird, he admits one of his favorite areas to go birding is the Kasota Prairie. “I’ve seen my share of rarities there,” he says.

Al Batt of Hartland is an avid birder and naturalist and has often led groups on Great Minnesota River Birding Day. This year, he will be delivering the keynote address at the 2007 Midwest Birding Symposium in Moline, Ill., on Saturday.

He says he’ll miss being at the eighth annual event on the Minnesota River. “It’s a long, long trail and a unique region.”

Particularly, he’ll miss being at the rally at the end of the birding day, at 4 p.m. At Elks Nature Center at Rasmussen Woods in Mankato. “There’s always something to entertain me (at Rasmussen Woods),” he says, adding that hearing of all the species seen by the teams is particularly exciting.

Of the 425 species sightings recorded in Minnesota, 320 of them have been in the Minnesota River Valley along the trail. “Many people struggle to see 300 species in (all of) Minnesota,” he says.

Batt is a member of Audubon Minnesota and believes birders need to make themselves better known for their economic impact in the area. “We’re kinda sneaky. We walk into a cafe, and we look so regular. We’re not like hunters who wear orange vests,” he says only somewhat jokingly.

In addition to eating in local restaurants, birders put gas in their cars, stay in motels, and buy newspapers and other items. He encourages people who are in an area to go birding to leave cards saying, “You’ve been visited by a birder.” That might help put more money into birding trails and sites at many levels in Minnesota, he says. “But, if you’re in a restaurant and you don’t leave a good tip, don’t leave the card.”

The Great Minnesota River Birding Day is open to anyone interested. Williams says he will pair novices with those more experienced, and will gauge accordingly how extensive a loop is assigned. He also will pair birders to groups visiting areas where they are likely to see their favorite birds.

For more information or to register for the event, contact Williams at (612)728-2232.