Thursday, January 18, 2007

Half a million snows

When wildlife agents determine that a species should not be hunted or collected in order to save it from inevitable demise, it's a big deal. 30 years ago, duck hunters weren't allowed to kill wood ducks because their populations were so small. Wood ducks have rebounded so handily that now there isn't enough breeding habitat to accomodate the population. Two years ago, over 50 sterile eggs were found in a single nestbox. The population is doing fine for now, but with the continued destruction of freshwater wetlands, their population might not be as stable in 20 years.

In 1916, snow goose hunting was outlawed because of a dramatic drop in their population. With the conversion of land to agriculture after World War II, snow goose populations increased so drastically (due to substantial winter food sources) that hunting was allowed again in 1975. Snow geese migrate from the Arctic tundra through the Midwest to the Gulf Coast, feeding on flooded grain fields along the way. In recent years, with thousands of acres of crop residue left in midwestern fields, the birds are "shortstopping," staying in the Midwest rather than making a full migration. When these populations return to their breeding grounds, full from the unlimited food supply, they have an increased ability for reproduction and are, in short, destroying their breeding grounds. In 2001, 1/3 of snow goose breeding habitat had been converted to salt plains and mudflats by overgrazing. Another third is greatly degraded and is being restored by wetland managers. The last patch of habitat is not so badly damaged, yet. With snow goose populations estimated at 6 million birds, that last third of the nesting habitat must be fiercely defended if any is to remain viable.

The population boom might be headed for a crash. With less food available for the hatchlings in the breeding grounds, the young birds starve to death or are too weak to make the annual migration south. Since the breeding grounds are so badly degraded, females are taking the young further away from the breeding grounds to raise them, areas with food that isn't as nourishing for the young.

Hunting hasn't made a dent in the population. Some states don't have a limit on how many snow geese hunters can kill (in Missouri and Louisiana, it's 20/day) and the season on snows increases almost every year. Hunters find it difficult to hunt the birds when they are in such large flocks. Apparently, you have to sneak up the flock to shoot one but if you scare one, you scare the whole flock away. To attract the geese to a certain field, you have to wake up really early and set out hundreds of decoys and then wait for the flock to find them.

On any given afternoon, 500,000 snow geese can be seen on a single field or pond in southeast Missouri. Around sunset, their calling (more of a "whounk" than a Canada goose "honk")can be heard for miles as they make their way to Reelfoot Lake for the night. With all the rain in the past few weeks, almost every field is flooded and at some point during the week hosts thousands of these large gregarious birds. People stop their trucks in the middle of the road to watch them settle in for a landing. This is probably the only time of year when the regular gunshots don't unnerve me.

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