Like other large waterfowl species, the North American population of snow geese was decimated in the early part of the twentieth century due to overhunting. But since then, thanks to hunting restrictions and habitat protection, snow geese numbers have bounced back strongly – some might say a bit too strongly.
Wildlife management officials are now trying to curtail the growth of snow geese colonies on the North Slope, before they get out of hand.
Numbering in the millions of birds, dense colonies of snow geese on the breeding grounds in the central Canadian Arctic have cause widespread ecological damage there.
As Julian Fischer from the U.S. Fish and Wildlife Service Migratory Bird Management Office explained, an overabundance of snow geese in an area will leave the land barren and ripe for erosion.
“And that’s due to the fact that snow geese have a very robust bill, that’s capable of excavating root systems, and that results in the organic layer being stripped away,” Fischer said.
Extensive habitat degradation has not been seen yet on the North Slope of Alaska, which is home to several snow geese colonies. But snow geese numbers in Alaska are exploding. North Slope Borough Department of Wildlife Management biologist Brian Person monitors the largest colony in Alaska, located about 60 miles southeast of Barrow.
“Last year we enumerated 12,000 nests,” Person said. “To put that in perspective, in early 2000, there were only 250 nests out there, so it is growing exponentially. We think the population is doubling every three years.”
The snow goose population in Alaska as a whole continues to grow despite the fact that in some years, almost all of the nests in a particular colony fail to produce goslings. The reason? Brown bears – who treat snow geese colonies as a kind of all-you-can-eat buffet serving only one thing: eggs.
In 2009, when an estimated 99 percent of snow geese nests in the Ikpikpuk colony southeast of Barrow failed due to bear predation, Person watched it happen.
“At any given time, I never had more than a half mile visibility because of the fog,” Person said. ” And at one time we counted four bears, going to nest to nest to nest, eating these eggs. It’s a wonderful food source for the bears.”
But despite hungry bears and humans with shotguns, snow geese numbers in Alaska continue to skyrocket. One reason is that snow geese are fairly long-lived birds, with a maximum life span of 10 to 12 years. So they have many opportunities to reproduce. They’re not picky eaters. And there’s another factor in play, according to Julian Fischer from the Fish and Wildlife Service.
“From models that are being produced by the USGS Science Center, it appears that the growth is faster that can be explained by just production of goslings alone, suggesting that there must be emigration from another breeding area,” Fischer said. “Most likely that would be coming from the Banks Island area of Canada, or possibly even the central Canadian Arctic.”
Snow geese from overcrowded areas in Canada, it seems, are seeking greener pastures in Alaska.
Liberalized hunting regulations in the lower 48 and Canada aimed at reducing the Canadian breeding stock of snow geese have not proven to be effective to getting the population down to a sustainable level. But nevertheless, biologists like Person think that subsistence hunters and egg collectors on the North Slope can play a role at regulating the Alaska breeding stock now, before the population gets too large.
“I think that’s really the only good alternative in this case,” Person said. “I think hunters in the lower 48 and Canada are already saturated.”
Expanded subsistence hunting in Alaska can be an easier tool to wield on the snow goose situation, because changes to hunting regulations at snow geese wintering grounds in the lower 48 would require federal authorities to go through the National Environmental Policy Act review process.