Book recounts history of cormorants, 'feathered pariahs'

Linda Wires, wildlife biologist at the University of Minnesota, has written a book for our times. It is about disregard for science, in this instance by sport fishermen, and acquiescence by government, letting fishermen have their way.

The book is "The Double-crested Cormorant: Plight of a Feathered Pariah" (Yale University Press, $30).

If you care about birds, this is an important book. It discusses the social and scientific aspects of the species, and the bird's centuries-old problems with man. Much of its detail concerns extreme efforts to control cormorant populations. Birds are shot. Chicks are crushed. Eggs are oiled. Nests are scattered. The book can be grim.

It is an ethical issue, Wires believes, with a long history.

In the Bible, in Isaiah, written about 700 B.C., cormorants are described as unwholesome and hateful. Chaucer, writing in the 14th century, called the bird a glutton. Shakespeare did the same. Audubon, too.

"Its unique appearance has inspired fear and disgust and its fishing skill has inspired anger and hatred," Wires writes. She suggests that the color of this iridescent black bird has been a factor.

"Animals so colored were frequently associated with evil, witchcraft, magic, superstition, premonition, otherworldliness, and all things dead" in medieval Europe, she writes.

Today, we have science, but that science hasn't made much difference in how opinions are formed. Opinions of many fisherman and people who have economic ties to fishing continue to focus on raw observation, pretty much as in 700 B.C.

Complaints are collected by the U.S. Fish and Wildlife Service (USFWS), which has found itself involved in killing birds it is supposed to defend. Cormorants are protected under a migratory bird treaty with Mexico. Solutions — reducing cormorant populations — come from Wildlife Services, a Department of Agriculture agency, with permission from USFWS.

Loons and mergansers eat more fish than do cormorants, as a percentage of body mass. Wires points out that loons and mergansers, however, are solitary feeders, at most a pair on the water.

Cormorants are colonial nesters, highly social, Wires writes. That means they congregate to nest, and congregate to feed. There's the rub: We see throngs of birds, all with exceptional fishing abilities.

North America has an estimated double-crested cormorant population of 1.1 million. That's despite an estimated kill of half a million cormorants since 1998, not including uncountable numbers of eggs destroyed.

Five other cormorant species found in North America are fewer in number. They aren't singled out for the same treatment.

Scientists have done their best to bring facts to the discussion. More than two dozen scientific studies have come to the conclusion that cormorants do not reduce game-fish populations, Wires writes. Cormorants eat fish, yes, but few of the species fishermen covet. A handful of studies have come to the opposite conclusion.

This is a complicated issue. It has no simple answers. It even has become political, with culling proponents going to Congress for help.

Other reasons for fish populations declining — water quality, invasive species, overfishing, illegal take of game fish — rarely appear in complaints.

The key fish species is walleye. A decline in fishing success for walleye was the argument presented when cormorant control was initiated at Leech Lake in 2005. Thousands of cormorants, some of them returning to nests to feed young, were shot so the food in their stomachs could be examined. Few walleye were found.

Control of that population continued on the grounds of cormorant competition with nesting common terns, a bird of special concern in Minnesota.

So too were game fish central to the request for cormorant culling at Lake Waconia beginning in 2008. Eventually, a depredation order was issued at the request of the owner of the island where cormorants were nesting. His plea was legitimate; cormorant guano kills vegetation.

Wires writes that cormorants in Canada have been subjected to the same maltreatment as birds in the United States, mostly on the eastern Great Lakes.

What's different there, she points out, has been the aggressive response of the birding community. Birders have actively opposed culling efforts, some even putting themselves in canoes positioned between cormorants and the guns pointed at them. Here, Audubon Minnesota wrote letters and organized comments on both the Leech Lake and Lake Waconia removal efforts.

Rallies of the type organized to protest the Vikings' stadium glass issue — addressing concerns about possible songbird deaths — were missing.

Lifelong birder Jim Williams can be reached at woodduck38@gmail.com. Join his conversation about birds at www.startribune.com/wingnut.