Biologists: snow goose explosion must be cut by half
When a white, funneling cloud of snow geese descends on a Sussex farmer’s winter wheat field, brown patches of field start showing where tender blades of green used to stand.
That’s a big enough problem in Delaware, where the average wintering population for snow geese over the past several years has been in the 125,000 range. But consider the wheat farmers of Quebec who see more than a million of the greater snow geese pass over each spring on their way back to their high arctic breeding grounds. At least they don’t hang around Quebec for long. They’re headed home. Spring and summer mean breeding and nesting season and that takes place on the arctic tundra. There lies the greatest concern for scientists who study what has become part of the winter landscape for us on Delmarva.
Matt DiBona, a waterfowl biologist for Delaware’s Division of Fish and Wildlife, says consider this: In 1965, the entire Atlantic Flyway was home to about 25,400 snow geese that split their time between the Arctic tundra in the summer and the marshes of Virginia and the Carolinas in the winter. But when the geese began wintering farther north, they found higher quality food in the grain fields of Delmarva. “They used to roost and feed in wetlands,” said DiBona. “They were strictly a wetlands species. But the higher energy food they found here allowed them to better survive the energetically stressful winters and migrations.” By 2006, he said, their numbers had exploded to more than 1 million birds. “In Delaware in the 1970s, we were seeing not many more than 1,500 snow geese in the winter. Now, 125,000 to 150,000 birds at any one time is not unusual here.
“It’s a perfect example of exponential population growth,” says DiBona. “That’s an 8 percent annual growth rate. The concern among the waterfowl managers is that the fragile vegetation of the tundra where the snow geese breed can’t recover fast enough after the pressure that 1 million foraging birds brings. One of these years that could lead to not enough for the birds to eat, resulting in starvation, poor breeding production and a crash in the population.”
DiBona said waterfowl biologists monitoring snow goose populations in the Atlantic Flyway have set 500,000 as an optimal target population. That means cutting the current population in half. “It sounds aggressive until you consider the larger implications: a much larger population crash as well as the continuing damage to the vegetative communities of the tundra and farmers’ crops. We have to reduce the negative effect on the breeding grounds.”
Liberal hunting rules helping
To that end, Delaware and several other states in the flyway adopted a federal conservation order setting an unprecedentedly liberal special hunting season for snow geese. From February into April, when there are no other waterfowl seasons open, hunters are encouraged to kill as many snow geese as they can. The conservation order, with a free permit from the state, allows them to use electronic recording devices to attract snow geese to their spreads of decoys. Hunters may also use unplugged shotguns, which doubles the shell capacity from three to six. There are no limits on how many snow geese a hunter can kill in a day, or possess. Several Sussex County snow goose hunts in February produced bags of as many as 30 geese per hunter.
“We want to avoid the population crash,” said DiBona. “Bring the population down gradually.”
He said in 2012, Delaware issued 832 permits for the conservation order season. Of that number, 547 hunters actually participated and killed about 6,400 snow geese. In the entire Atlantic Flyway, it’s estimated the 2012 conservation order season recorded 36,853 geese killed and another 2,500 unretrieved cripples.
DiBona said data is being analyzed from Delaware, Maryland, Pennsylvania, Virginia, North Carolina, New Jersey, New York and Vermont – all states where the conservation order is in place. “They’re trying to determine how effective the order has been in reducing the population. Just eyeballing the situation, I’d say the conservation order has stabilized the population, but it’s not really reducing it.” DiBona flies waterfowl counts from October through February in Delaware to estimate populations.
“The federal managers would like to see this population cut in half by 2015 – but that’s not going to happen. Right now we’re in a wait-and-see mode. We want to exhaust all efforts through traditional means before we start looking beyond to other tools.”
He said going to the breeding grounds to take more direct action – such as addling or smashing eggs - isn’t an easy prescription. “They’re way up in the arctic out in the middle of nowhere. Getting out there to do anything – all the logistics involved in taking people, equipment, food and everything else - it gets real expensive real fast.”
In the meantime he hopes more hunters will take advantage of the additional recreation – and meat in the freezer - the conservation order offers to help take some of the sting out of this environmental imbalance.