Snow geese swarming Springfield

It’s sometimes hard to believe that early settlers described flocks of birds so immense they darkened the skies.

John James Audubon — the famous early 1800s bird artist — wrote about flocks of passenger pigeons that took days to pass.

“The pigeons were still passing in undiminished numbers, and continued to do so for three days in succession,” he wrote in “The Birds of America.”

It is certainly hard to picture. But it becomes a bit easier after a visit to Lake Springfield in late February.

Last Wednesday, tens of thousands of snow geese — including snow, blue and Ross’s geese — carpeted Lake Springfield north of Lindsay Bridge.

They sat on the lake in a giant kidney-shaped raft. Every once in awhile they would decide to get up and move.

It’s then that the word “carpet” is most appropriate. They start at one end of the flock, taking to the air from one end to the other, as if an old carpet was being pulled up.

When the flock took off together, it obscured the far shoreline of Lake Springfield. The smokestacks of the City Water, Light and Power plant momentarily disappeared in a whirl of white and black

It’s not a new spectacle. Snow geese have been making spring appearances at Lake Springfield for some time now. But it is no less impressive whether it’s the first time or 10th time.

Snow geese — a blue goose really is just the dark color phase of a snow goose — once were near extinction.

They have staged a comeback as spectacular as their spring migration shows.

Snow geese have prospered partly because they have learned to exploit waste grain during migration.

The U.S. Fish and Wildlife Service says there are more than 5 million breeding snow geese. Their numbers have tripled over the past 30 years they’ve been counted during the winter.

Unfortunately, wildlife experts fear snow geese will become victims of their own success.

They nest in Canada, and the Arctic tundra they choose for nesting is fragile. If too many geese dig up too many roots and tubers, it can take too long to recover.

According to the Fish and Wildlife Service, snow geese may be competing for resources and space with other birds.

“Large areas of the breeding grounds around Hudson Bay have been denuded of all vegetation by geese through overgrazing, grubbing and shoot-pulling,” says a Fish and Wildlife Service report. “(It is) a situation that scientists believe may also be contributing to the decline of breeding populations of other migratory bird species that share the breeding grounds and winter in the United States.”

To compensate, hunting rules have been loosened and goose hunters have been given a whole new arsenal of ways to take them. Snow geese can be hunted through March 31 — well after other waterfowl seasons have closed.