GREAT OUTDOORS: Migration of unpopular cormorants underway

As I fished last Friday in the Sandusky Bay with catfish guide Scott Heston, I could not help but notice the thousands of double-crested cormorants that shared the water with us. Also known as fish crows, sea crows or crow ducks, their scientific name, phalacrocorax auritus translates to "bald crows with ears," referring to the tufts above their eyes, the "double crests" that develop during breeding season. The adults are all black, except with yellow skin on their throat that turns orange in mature birds. The yearlings are browner, with a lighter breast. Despite their greasy appearance, the feathers are not fully waterproof. After an extended time in the water, the birds are often seen with their wings outstretched to dry them in the breeze or sun. One Ohio Division of Wildlife biologist estimated that daily flights during the fall migration reach 25,000 birds with hundreds of thousands passing through annually. During the summer, they seem to be just about everywhere in the state, from the Lake Erie Islands, up the tributary rivers, on reservoirs and isolated ponds. The number of nesting pairs in the Great Lakes went from tens of thousands in the 1950s down to 125 pairs in 1973 due to the effects of DDE, produced by the breakdown of the pesticide DDT. At levels over 15 parts per million, these chemicals cause brittle eggshells and chick deformities such as clubbed feet or cross-beaks. In 1972, DDT was banned as DDE levels in their eggs reached 22 ppm. Within a few years, egg and chick survival began to increase on Ontario's East Sister and Middle Islands. The first nest on the U.S. side of Lake Erie on West Sister Island in 1992 was celebrated by birders as a sign of the lake's recovery. By 2004, there were an estimated 12,973 nesting pairs on the Canadian Islands alone. The Sandusky River and the connected tributaries leading to the bay are very productive fish nurseries and scores of young fish produced there have captured the birds' attention. Cormorants are opportunistic feeders and local studies show that they prey upon whatever fish species is currently abundant in a given location. Here, they may be targeting white perch, white bass, yellow perch, gizzard shad or emerald shiners. Almost entirely piscivorous (fish-eating), they have long been accused by anglers of decimating local populations of game fish such as yellow perch, walleyes and smallmouth bass. A photograph shared on the internet purportedly shows the stomach of a cormorant filled with young of-the-year yellow perch, supporting fishermen's arguments that the birds need to be controlled. In fact, the Federation of Anglers and Hunters in Ontario convinced their wildlife agency to allow a season on them to protect their fish populations. The first proposal allowed a year-round season and a limit of 50 birds per day. After the dust settled, the season was set to run from September 15 to December 31 with a daily limit of 15 birds. Despite the willingness of many anglers and waterfowl hunters to volunteer to help shoot cormorants here, there is currently little hope of an open season in Ohio. With no value as table fare, there is no support for it within our wildlife agency to list it as a game species. The effect of cormorants on Lake Erie's huge fish population is minor compared to the damage done by their acidic droppings that whitewash and kill the island trees required for nesting by herons and egrets. To prevent the islands from becoming reduced to bare rocks and to protect these higher-value birds, the Ohio Division of Wildlife has been working with federal agencies to cull cormorants on West Sister, Green and Turning Point (in the Sandusky Bay) islands, and at a couple of inland locations. After fighting with animal rights groups for the right to cull them in Ontario, they are following suit on their islands to protect the remaining vegetation.