FRESNO, Calif. - If it looks like a duck, acts like a duck and flaps its wings like a duck, conventional wisdom dictates that it is, in fact, a duck.
But not always.
Not when the duck in question is really a Mojo Duck, RoboDuk or any other brand of spinning-wing decoy that waterfowl hunters use to lure real birds into shooting range.
Spinning-wing decoys, whose motorized, battery-powered wings rotate rapidly to simulate a bird landing on a pond, are more widely used but no less divisive among duck hunters than when they were introduced a decade ago.
The debate whether these faux fowl are legitimate hunting tools or provide an unfair (and unnecessary) advantage to those who use them continues to ruffle feathers at public hunting areas and private duck clubs.
Just about the only thing hunters on opposite sides of the spinning-wing decoy debate agree on is that they work as well as advertised.
"I think they've taken away from the art of duck hunting," said Darrel Rerucha of Madera Ranchos, Calif., habitat manager for a private duck club. "Nothing ticks me off more than to see a guy walk into a pond and all he has is a spinning-wing decoy.
"He's lazy. He doesn't know how to arrange a (decoy) spread. He doesn't know how to call ducks. And yet he's pulling birds away from you."
Fellow duck hunter David Borchardt of Fresno, who deploys one or two spinning-wing decoys in his spread of stationary decoys, doesn't see it that way.
"My thinking is if I'm going to spend all the time and energy trying to get some birds, why not use every advantage that you can?" Borchardt said. "If a Mojo Duck brings them closer to you so you can have a humane kill and a better chance of retrieving that bird, all the better."
Plastic decoys debuted in the 1960s and remained unchanged for four decades until two Marysville, Calif.-based companies, RoboDuk and Roto Duck, introduced the first motorized models in November 1998. The response was immediate, and stores couldn't keep them on their shelves.
Ten years later, RoboDuk is still going strong, Roto Duck is out of business and Mojo Outdoors, based in Bastrop, La., has emerged as the leading manufacturer of spinning-wing decoys. A Mojo Mallard, which comes in both hen and drake color schemes, retails for about $130.
Marketed as "the quietest, most powerful and durable motorized duck attractor on the market," Mojo Mallards have 3-foot-wide aluminum wings that can be adjusted to produce different wing-tip actions. Powered by a 6-volt battery, the direct-drive motor can keep the wings churning up to 20 hours.
While states like Oregon, Washington and Pennsylvania have outlawed spinning-wing decoys, California has taken a different approach. They're prohibited before Dec. 1 but legal for the rest of the season, which ends in late January.
Dan Yparraguirre, senior wildlife biologist for the California Department of Fish and Game, said the Dec. 1 stipulation is meant to protect locally born mallards from being decimated.
"Resident ducks that hunters shoot early in the season tend to be incredibly naive," Yparraguirre said. "By December, the ducks that come down from Alberta (Canada) have been hunted since September and are pretty savvy to decoys."
A 2000 UC-Davis study concluded that hunters who used spinning-wing decoys early in the season killed six times as many birds as those who didn't and three times as many ducks late in the season. At the same time, the DFG interviewed 10,000 hunters and found those who used motorized decoys killed one duck per day more than those who didn't.
Nonetheless, overall harvest rates for California waterfowl have declined or remained virtually unchanged since 1998.
"There's no question that they work," Yparraguirre said. "Hunters wouldn't use them if they didn't. But can we say for certain they're affecting the waterfowl population? Not at all."
Even some hunters who dislike the idea of spinning-wing decoys still occasionally use them-albeit reluctantly-to keep up with those who have no such qualms.
Rerucha belongs to this group, and so does Fritz Kyer of Clovis, Calif.
"The sad part is a lot of us that hated them still went out and bought the dumb things because we couldn't get any birds to come to us because of the other guys," Rerucha said.
Added Kyer, "I'd rather not use them, but it's almost like you have to these days."
Jerry Mele of Fresno, a former director of California Waterfowl, used to belong to the anti faction but has reversed his thinking.
"On bad-hunting days, it might add one or two birds to your bag," Mele said. "That difference is enough to keep certain people hunting, and I don't think that's a bad thing. . . .
"It might mean a guy's going to continue hunting this season instead of giving up. And he might even take his kid. To me, that's why I've worked with California Waterfowl, Ducks Unlimited and all these different organizations. I want to see our hunting heritage continue."