Tim Turenne has a theory on why he mustered only a fifth-place finish in last year’s inaugural Minnesota Walleye Habitat Stamp contest.

“The quality of my fish was better than anyone by far,” said Turenne, a veteran wildlife artist who enters up to a dozen wildlife stamp competitions ever year. “But they all showed the whole fish. My painting only showed about three-quarters of a fish. I guess they were looking for the whole fish.”

Divining the judges’ artistic sensibilities is serious business for regulars on the wildlife stamp competition circuit. Winning the contests — there are five per year just in Minnesota — can mean prestige, cash and a big boost in painting sales.

Turenne lives with his male partner of 21 years in a split-level house across the street from a freeway sound barrier in a Minneapolis suburb. He’s won six stamp competitions in about four years by painting a series of fish, ducks and turkey with just the right combination of visual vigor and lack of pinpoint detail that looks good when shrunken to postage-stamp size.

But he’s never won the Academy Awards of wildlife stamp art — the Federal Duck Stamp contest, which just marked its 75th anniversary. Entries for the 2010 stamp are due Aug. 15, and Turenne has been hard at work in his basement studio on a painting of two wood ducks.

“It’s been a long time since the wood duck has won,” he said hopefully.

The first thing to know about wildlife stamps is that they’re not postage stamps.

Instead, the federal government and states including Minnesota require hunters and anglers to buy and affix the stamps to hunting and fishing licenses. Proceeds going to preserve outdoor habitats.

The stamps have become collectibles. Mint-condition copies of the first federal duck stamp, sketched in 1934 by J.N. “Ding” Darling, a Des Moines editorial cartoonist, can fetch $15,000 or more, said Bob Dumaine, the founder of the National Duck Stamp Collectors Society.

Many stamps, particularly those that win the federal or the more prestigious state contests, eventually get reproduced in a size suitable for framing, and adorn many a basement wall — particularly in the outdoors-oriented Upper Midwest.

“When we dress up and go down to see the Monet exhibit, we’re in with a different crowd,” said Dumaine, who lives near Houston, Texas. “I don’t see guys with hip boots on. Does that have a larger following than duck stamps? I guess so. Does that make it better? I guess that’s a matter of taste.”

Whether wildlife stamps belong on museum walls next to the Hoppers and the Hockneys may be debatable, but there’s no doubt winning wildlife stamp competitions can launch artists’ careers.

Scot Storm, a former architect in Freeport, has been earning a living as a full-time wildlife artist since winning the Federal Duck Stamp competition in 2004.

“Winning contests is a big part of it,” Storm said.

There’s no shortage of competitions to enter. Minnesota has a Walleye Habitat Stamp contest, a Trout and Salmon stamp contest, a Migratory Waterfowl Stamp contest, a Pheasant Habitat Stamp contest and a Turkey Habitat Stamp contest. Entry deadlines for all but the turkey stamp contest fall between this Friday and Oct. 23. Artists who want to make a go of the turkey contest have until next January.

Minnesota is home to more Federal Duck Stamp competition winners than any other — 15 painters who have racked up 22 of the 75 wins. The list includes some of the biggest names in wildlife art, including Les Kouba, along with Jim, Joe and Robert Hautman, three brothers who together boast eight federal wins and were memorialized in the movie “Fargo” when Sheriff Marge Gunderson’s husband, a wildlife stamp artist, expressed jealousy over their success.

Minnesota is by no means alone in creating opportunities for wildlife artists. In all, about half the 50 states have at least one wildlife stamp competition. But there aren’t as many competitions as there used to be, not as many artists enter any more and some aficionados grouse that the wildlife art market has been flooded with so much sub-par art that the work of the truly talented is devalued.

“Every time you walk into a rural gas station you see a painting of a duck on a piece of wood,” Dumaine said.