Snow geese damage marshes

Emily Dalnodar

Northern marshes are being turned into empty, desecrated mud flat wastelands. The culprit? Snow geese.
These marshes are the breeding ground for snow geese. Once destroyed, some fear the species will take over the habitat of the Canada goose — a popular game bird in Minnesota. If this happens, Minnesota hunting and land conditions could be greatly affected.
The snow goose population has been on the rise the last 25 years, but numbers are hitting an all-time high. This year there is an estimated 4.5 or 6 million birds, triple what the population was 25 years ago.
Although effects of the snow goose invasion aren’t apparent in Minneapolis, northern Minnesota and Canada can clearly see the signs, said David Anderson, University goose researcher in the Department of Fisheries and Wildlife.
The population growth is due to the birds’ wintering habits. They fly south to Louisiana, Texas and Mississippi to nest. The conditions and food availability has made it so more birds survive the winter and the trip back north.
The period over which they’ve increased correlates to a change in agriculture practices, said Ken Abraham, wildlife scientist at the Ontario Ministry of Natural Resources.
After World War II, there was an increase in man-made fertilizers, yielding an increase of corn, rice, wheat and other crops. There have also been other changes in agricultural practices causing an increase of production in cereal crops.
“It is not any agricultural practice in particular, so there’s no way to put a finger on one thing,” Abraham said.
“The geese find the agricultural areas better than the natural areas. The geese have escaped from any natural limits. They are not doing this on their own; it is in response to human practices,” Abraham said.
Usually, about 70 to 75 percent of the birds make it back to Canada in late winter and early spring. But the surviving number of snow geese has steadily climbed each year to reach 95 percent in the last couple years, Anderson said.
Because so many survive, they strip the capacity of the breeding ground.
The snow geese, which are named for their white feathers, are destroying salt marshes where they nest in the summer. The main areas of destruction are in South Hudson Bay, which is at the northern limits of Manitoba and Ontario, Canada, and James Bay, about 500 miles north of Toronto, Canada.
About 30 percent of the salt marshes are completely destroyed, leaving them as inhabitable mud flats. Another 35 percent of salt marshes are significantly damaged, Anderson said.
There are three possible solutions: Let the problem take care of itself and wait for the population to crash, deal directly with the population by changing hunting limits and regulations or address the cause of the problem in the south, Anderson said.
Right now it seems the most likely answer is to change the population figures. This means increasing hunting seasons for snow geese, allowing electronic goose calls and baiting methods, and bumping up the bag limits.
“No one is talking about slaughtering or wasting the geese; it all should be used for food. No one is suggesting the population should be reduced by half in a single jump, either. Just increase the rate of killing to a point that the population is declining at 5 to 15 percent a year,” Abraham said.
In some states the bag limits have already increased and the hunting season has been extended.
Though Minnesota is not one of the major states for hunting snow geese, some are shot in the state each year.
Because the snow geese are destroying their original habitat, they’re moving into the habitats of Canada geese, which migrate through western Minnesota.
This bird is seen frequently in Lac Qui Parle, Minn., which is traditionally a big hunting area. If the Canada goose population crashes it will have an effect on hunting in the state, said Tom Lamdwehr, wetland program coordinator for the Department of Natural Resources.
There are a lot of birds who breed in Minnesota. If there is a shortened hunting season because of the crash of the Canada goose, then local birds will thrive and damage crops and other state lands.
“There are all kinds of weird twists that happen because of the goose population,” Lamdwehr said.
Officials are unsure whether just rearranging hunting regulations will be enough to curb the problem.
“I think it is a long-term situation. People became aware of the problem 10 years ago. It will be another 10 to 20 years before it will go away, if it goes away,” Anderson said.
If the birds were all taken away right now and the salt marshes began repairing themselves, it would still take at least 20 to 30 years before they are back to normal, Anderson said.