Climate Change Could Mean More Geese, Better Goose Food in the Arctic
Fairbanks, AK - The first two Canada geese arrived at Creamer’s Field Migratory Waterfowl Refuge Friday, according the Alaska Department of Fish and Game. For birders across the interior the charismatic birds are a sure sign of the oncoming spring. More of the birds will start to land on the field as the weather warms. A recent study finds that climate change in the Far North is improving goose habitat, but that doesn’t mean the field will be overrun.
Soon the sound of traffic along College Road will be drowned out by the familiar, collective honk of hundreds of Canada geese. But for now, the tires on pavement are mostly only interrupted only by the occasional chattering squirrel, or a quietly chirping chickadee…
The geese stop at Creamer’s Field to feed before they head further north to molt, or shed their outer wing feathers. But where they molt on Alaska’s North Slope is changing. “So, the birds have been leaving these inland lakes and moving out to the coastal zone and molting out there on what are basically small estuarian salt marshes," says Paul Flint is a research biologist at the Alaska Science Center in Anchorage. For roughly a decade, he and colleagues have conducted aerial surveys and captured and banded Black Brant geese on the Arctic Coastal Plain and in the Teshekpuk Lake Special Area on Alaska’s northern coast. Flint says prime habitat for Arctic geese is expanding. “We went out to those salt marshes and sampled the vegetation to see if it was of high quality and high availability.” Those plants are the kind Black Brant love to eat. Flint says their emergence is likely a result of climate change. “And so what it looks like has happened is that permafrost degradation has caused ground subsidence, such that these areas area inundated with salt water on a regular basis, covered over in sediment and then grow up these salt tolerant pant species which are a preferred forage of these molting geese," explains Flint.
He says the increase in forage and habitat expansion means the general goose population, which includes not only Black Brant but also Snow Geese, Canada geese and White-fronted geese to name a few, is on the rise. ”At a broader scale if you think about climate change or general ecological change, it’s almost always going to have some winners and some losers," Flint says. "In this particular example, we are creating an abundance of high quality forage, so geese are then doing what we expect animals to do. They are very good at finding habitats that are to their advantage and then using them. ” Roughly 100,000 geese arrive at Teshekpuk Lake annually. Flint says improved forage means breeding is also improving, but there are other factors that also limit population growth. “Especially for these migratory species like geese," he says, "there can be lots of food on the Arctic Coastal Plain, but if they’re really limited by food overwinter, perhaps down in the lower 48 or along the Gulf Cost, then they will never take full advantage of what’s up there on the North Slope, so because they are a migratory species, you have to consider where the bottleneck might be throughout their annual cycle and in this case, we don’t know where that may be.”
Flint can’t say for sure how things might play out for geese that migrate north in the long term.
“It’s kind of a bit of an arms race," Flint explains. "Because what’s happening is it looks like the permafrost on the inland edge of these things is degrading, dropping down to where salt becomes more dominant and then the plants that exist there now can’t tolerate the salt, but these grazing lawns that the geese like can so it converts to the slat tolerant species, but at the same time, we’re seeing high rates of erosion on the coast, so we’re gaining on the inland edge and losing on the outer edge and we don’t yet understand which of these processes is going to be dominant,” he says.
Flint and colleagues’ work appears in the latest issue of the Journal of Field Ornithology… perhaps a good read for those who are still waiting for more of the season’s geese to arrive at Creamer’s Field.