Alaska's emperor geese migrate north for their winters. Fluffy new down keeps the geese warm in their winter territory, which spans from Kodiak Island west across the Aleutian chain.
The current migration record belongs to a bar-tailed godwit that flew 8,425 miles non-stop between Alaska and Australia in 2022.
When termination dust sprinkles Alaska's mountain peaks, the summer tourists depart in campers, cruise ships, and V formations soaring over the yellow birches. An estimated 5 billion birds from 250 species visit Alaska to breed each year, following established migration routes called flyways. But even bountiful Arctic ecosystems can't feed this many birds all year round. At the end of nesting season, these nomads embark on incredible-and increasingly difficult-journeys to their winter homes.
The northern wheatear flies 8,500 miles from Alaska to Africa, claiming the longest east-west flight path of any bird. Arctic terns chase the sun all the way to Antarctica; during their 30-year lifespans, they travel the distance between earth and the moon three times. Tiny blackpoll warblers, which weigh only as much as three nickels, trek from Denali to South America. The current migration record belongs to a bar-tailed godwit that flew 8,425 miles non-stop between Alaska and Australia in 2022.
To prepare for these epic trips, migratory birds find a safe place to molt and don fresh feathers. Some species undergo more dramatic changes. "They'll start to essentially change their whole physiology, and in some cases their anatomy," says Robyn Thomas, a Master's of Science student studying waterfowl. Body parts unnecessary for migration, such as reproductive organs, "will shrivel up, and energy will be shifted toward things like their flight muscles for the long haul." Bar-tailed godwits even shrink their digestive tracts since they won't eat until they reach their destination.
Other species do make pit stops, but human development threatens many critical "stopover" sites. Urbanization, agriculture and industry diminish habitats migratory birds rely on to rest and refuel. Since conditions in multiple countries affect these birds' survival, conservation becomes an international challenge. A 2015 study of 1,500 migratory bird species found that only 9 percent had protection throughout their range, and just 22 percent of their key stopover sites were protected. More than half the species traveling by flyways have recently suffered serious population declines.
Conservation isn't straightforward even for species that stay closer to home. One iconic example migrates almost exclusively within Alaska: the emperor goose. Western explorers gave this stocky blue-grey bird a magisterial moniker because its white head resembled fur trim on royal robes. Its Yupik name, nacaullek, loosely means "the one having a parka hood". About 90% of the population breeds on the Yukon-Kuskokwim Delta. When most migratory birds head south in autumn, "Alaska's goose" goes north to molt along the Chukchi Sea, venturing as far as Russia. Fluffy new down keeps the geese warm in their winter territory, which spans from Kodiak Island west across the Aleutian chain.
On those chilly beaches, Thomas studies the birds' wintering ecology and population dynamics. Her research supports a joint project between the U.S. Fish and Wildlife Service and the Alaska Department of Fish and Game. Despite frigid field conditions, the subjects can be heartwarming.
"The emperor goose is pretty unique in that it hangs out with its kids all winter long," says Thomas. Families travel together to their winter habitats, where parents show their young how to forage. Offspring may even return to associate with their parents the following season.
Even with devoted care, only one in 10 goslings survive their first year. Still fewer reach the breeding age of three. A slow reproductive rate makes emperor geese less resilient against population-level threats. Their numbers plummeted between the 1960s and the 1980s, for unknown reasons. Hunting and oil pollution may have played a role. Coastal waterfowl are also highly vulnerable to climate change. A hunting ban and 30 years of conservation efforts helped the emperor goose population recover to a healthier level by 2001. Subsistence harvest resumed in 2017, but may be suspended again if the population drops below a certain threshold.
Careful management preserves both the birds and the human heritage surrounding them. Emperor geese are an important cultural resource for Alaska Native peoples. "They're the only goose that stays in the winter...there are communities that would rely on that for some part of their diet during the winter months," says Thomas. She points out that indigenous knowledge has been crucial to the project's success: researchers struggled to catch emperor geese for satellite tagging until local Native people offered tips on the birds' behavior. "They know this bird better than we could."
Studying these migratory marvels can also help us understand how human activity affects wildlife. For example, light pollution can confuse birds that navigate by the night sky. Dimming outdoor lights during migration season gives them a clearer path. Domestic cats may prey on vulnerable molting birds, unless pet owners keep them under control. Window reflections can lure birds into deadly collisions, but special stickers on the glass can prevent these strikes. The Bird Treatment and Learning Center in Anchorage recommends Feather Friendly and Acopian Bird Savers, both available online.
Everyday actions like these will help welcome Alaska's winged visitors for many summers to come. Whatever the season, connect with BirdTLC to support birds from across the state. The clinic cared for more than 500 injured and orphaned birds in 2024. Bird TLC also offers conservation education programs for grades K-12 and the general public, inspiring others to care about the wild birds with whom we share the world.
J.K. Ullrich is a freelance science writer and author. She volunteers at the Bird Treatment and Learning Center in Anchorage.
