Bette Stallman, a wildlife scientist with the Humane Society of the United States--which filed suit against the U.S. government in February over cormorant management policies--is bothered by the precedent of killing wildlife that fishermen happen not to like. "This is going to create a precedent. It's going to be cormorants today, and it's going to be pelicans next time," she theorizes. Indeed, like cormorants, white pelicans have staged a comeback in Minnesota. While the birds do not congregate at the same densities as cormorants--and don't look so menacing--they eat on average four times as many fish as cormorants. At fish farms and rearing ponds, where bite-size fishes are plentiful and easy to snatch, flocks of cormorants and pelicans often clean out the inventory.
Whether the birds are capable of causing the same sort of damage to natural lakes--and natural fish populations--remains a subject of debate. "If you asked me that two or three years ago, I would have said no," says Steve Mortensen, a biologist who works for the Leech Lake Band of Ojibwe. But Mortensen thinks that Leech Lake may be one of the relatively rare bodies of water where cormorants are causing significant damage to the fishery.
"Obviously, something is going on with the walleyes," he says. "We don't have any evidence that the cormorants are causing it, but we can't find any other explanations, either." They'll get their answer this summer when the culling begins and researchers get to see what's in the guts of the dead birds.