The four radio-collar tulle geeks left their summer breeding grounds near the Cook Inlet in Alaska in the fall of 2020 and moved south for the winter. Migration usually takes four days: the birds fly over the Gulf of Alaska, stay about 100 miles from Canada, and land on the island of Vancouver. They stop briefly to float and rest in the Pacific Ocean a few times, and then converge on Summer Lake in central Oregon before making the final push to the Sacramento Valley in California. Last summer, however, migratory birds encountered heavy wildfire smoke off the coast of British Columbia and over Washington – and that’s when their behavior became bizarre.
A bird retreated about 80 miles north. The two spent about four days floating in the ocean before trying to get inland again; They flew straight into Oregon’s Beachy Creek Fire and then climbed about four times higher than usual to clear the huge ice of smoke. A fourth bird turned and flew farther east than usual, all the way to Idaho. Tule geese usually prefer to stay overnight in the wetlands, but these four stop at strange places, even once landing next to Mount Hood.
According to a Research published by the US Geological Survey (USGS) In early October, the birds’ 2020 migration took twice as long as the 2019 migration — nine days vs four — and they flew an additional 470 miles to avoid wildfire smoke. The paper states that “megafires and thick smoke pose a major problem for migratory birds” because wildfires are increasingly coinciding with the onset of autumn migration. There were 68 active wildfires in California, Oregon and Washington when the gauze crossed. Longer transitions require more energy and take longer to recover. This can make it harder for birds to reproduce and even put them at risk of death.
Corey Overton, a wildlife biologist at the USGS Western Ecological Research Center and lead author of the paper, was watching the isolated flight of birds in real time via GPS tracking. “I’ve been stuck at my computer for days, trying to figure out what these birds are doing because it’s very, very obvious, not normal,” Overton said. But all four birds eventually reached their favorite stopover in Oregon.
Overton and his colleagues believe that this is the first time that scientists have been able to document for sure how wildfire smoke changes bird migration. Birds begin to change their behavior when exposed to fine particles of 161 micrograms per cubic meter, which Threshold of the Environmental Protection Agency For “very unhealthy” air for humans. Migratory birds have been found dead across various western states and are dying in the same summer and early autumn and other conditions. Studies have found a link between death and toxic air.
Tule geese, a subspecies of the larger white-fronted goose, is a “special concern species” in California due to their small population; There are less than 10,000 of them. They are particularly vulnerable to flight interruptions because they follow the same route and stop at the same place annually. Overton and his colleagues were also tracking 12 additional waterfowl species, all of which migrated from Tulle Giz in the fall. As others passed through the area, the smoke almost disappeared from the Pacific Northwest. But as the fire season in the west lengthens, scientists are concerned that the smoke could prevent further migration along the Pacific Flyway. Many arrowbirds and songbirds are unable to store the extra energy needed to re-route around the fire.