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Field & Street

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Gulls and geese are dominating the bird news this winter. The gulls are getting noticed because of their rarity, the geese because of their abundance. Winter is the season for gull sightings around here. We can expect birds that nest along the shores of the North Atlantic or in the Canadian arctic to come south to the Great Lakes in this season. The usual species are glaucous, Iceland, Thayer's, and great and lesser black-backed.

This year, however, a California gull has been hanging out at Montrose Harbor, and that is unusual. The first recorded Illinois sighting of this species was in 1940, and the bird was not seen again until 1974.

It is easy to see why the species would be rare here. It nests around lakes and sloughs from Utah north to the Northwest Territories and winters along the Pacific coast. Despite its name, its breeding range includes only tiny pieces of northern California. Since its fall migration would normally be west or southwest from Utah or Alberta, a bird would have to get seriously off course to end up on Lake Michigan.

However, sightings of California gulls in Illinois have increased considerably in recent years. Starting in the early 80s, California gulls have been seen practically every year. Some sightings are from fall and winter. Others are spring sightings, presumably birds returning east from the Pacific and overflying their nesting grounds on the plains and in the Great Basin.

The sudden increase in sightings of this species could represent some change in its status. Perhaps it is moving east in response to some environmental change. But H. David Bohlen, in his Birds of Illinois, suggests an alternative explanation: "As Illinois birders become more sophisticated, optical devices more powerful, and field guides more accurate, the California gull becomes more numerous." In other words, they were here all the time--we just didn't notice them.

It is easy to see how these birds could be overlooked. They are very similar to ring-billed gulls, which are abundant here year-round. The two species are the same size and have the same general configuration. Both have gray mantles. (The mantle on a gull is the back and upper wing surface. When the bird is in the air these form a continuous gray covering.) Both have black wing tips flecked with white; both have yellow green legs.

The differences between the two species are small. Ring-bills have yellow corneas and California gulls have dark eyes. Adult ring-bills have a black ring around their yellow bills and California gulls have a black-and-red spot on the lower mandible only. The mantle of the California gull is a slightly darker gray than the mantle of the ring-bill.

Consider what is needed to make an identification here. First, you need to have looked at a lot of ring-billed gulls and placed the precise shade of gray of their mantles in your visual memory. Second, you need a precision pair of German binoculars--at a little over $1,000 a pop--or a spotting scope that is at least as expensive to give you a good look at eye color and beak markings on birds either in flight or standing on harbor ice 100 yards away.

But if you have the experience and the expensive equipment and you happen to be in the right place at the right time you can have the excitement of detecting a California gull, one of the few bird species to have a statue erected in its honor. The statue stands in Temple Square in Salt Lake City. It commemorates the two occasions--in 1848 and 1855--when flocks of California gulls arrived just in time to rescue Mormon grainfields from an infestation of Anabrus simplex, an insect now known as the Mormon cricket. It is an honor to have so famous a creature hanging out on our lakefront.

Geese hang out at Montrose Harbor too. They also hang out in parks, on golf courses, corporate campuses, and just about every other place with short grass. Just 25 years ago the Canada goose was a bird of passage here in northern Illinois. Then we introduced the giant Canada goose, a native midwestern subspecies that had been thought extinct until a small flock was discovered in southern Minnesota.

The giant Canada goose is more sedentary than the birds that used to pass through on their flights between their nesting grounds near Hudson Bay and their winter quarters in marshes along the Gulf Coast. The birds introduced to this region found a paradise. They were living in a place too thickly peopled to permit hunting, and everywhere they turned people were creating the short-grass habitat they favor. They could thrive here year-round.

In the early 70s birders thought themselves lucky to find even one Canada goose on a Chicago-area Christmas count--the annual bird censuses held during the two-week period bracketing December 25. This past December birders on the Barrington count reported 22,500 birds. A Christmas count censuses a circle 14 miles in diameter, roughly 150 square miles. Start extrapolating the Barrington numbers to the whole metropolitan area, and you arrive at a guesstimate of a goose population totaling hundreds of thousands of birds. It is conceivable that these huge honkers are now the most abundant birds in the Chicago area.

There are reasons to be happy about this. The cry of the goose is a compelling sound, an eruption of wildness in our generally tame landscape. I like looking up at the urban sky and seeing a passing flock, and I think a feeding flock makes a better decoration for a golf course than crowds of Republicans in funny clothes.

However, there is the doo-doo problem. Geese eat grass--and other vegetation--and they are incapable of digesting cellulose. To derive the necessary nutrition from their diet, they have to eat a whole lot, and most of what they eat passes right through them. Hence the expression "loose as a goose." If large numbers of geese are feeding in the outfield between baseball games they can coat the grass with a solid layer of guano.

Geese can also be slightly dangerous. They are aggressive in defending nests and young, and wings capable of propelling a 20-pound bird at 30 miles an hour or more can deliver a blow that can break a bone.

So once again we find ourselves face-to-face with one of the defining qualities of urban ecosystems. Human landscapes support fewer species than wild lands, but they often support very large numbers of individuals of those few species. So we have huge flocks of pigeons in the Loop, massive herds of deer in the leafier suburbs, and enough raccoons to populate a million square miles of prime botttomland forest.

And we no longer have the institutions to deal with these kinds of problems. A century ago market hunting was a big business. The marshes around Lake Calumet were so fecund that you could buy a mallard for a nickel in Chicago. Changes in our laws put an end to all that, and it is a very good thing that they did. Uncontrolled market hunting made a major contribution to the demise of the passenger pigeon, and if we hadn't stopped it we might have lost many more species.

So now we have to invent new ways to deal with excess geese. A bill has been introduced into the Illinois legislature that would allow the Department of Natural Resources to kill geese by such methods and in such numbers as the department finds suitable. Of course geese are protected by international treaties, so the state could not do anything without the approval of the U.S. Fish and Wildlife Service, and the feds would need to work out an agreement with the Canadians. But these things probably could be arranged. Geese are highly edible, and it has been suggested that the meat could be donated to food banks and homeless shelters. One caveat before we start sharpening our carving knives: Geese feed on golf courses, and golf courses typically measure their application of insecticides, herbicides, fungicides, nematocides, and other poisons by the ton. Somebody should analyze a few carcasses to find out what might be lurking in the meat.

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