17 September 2020 Seasonal Migration, From the Arctic To The World (and back!)

Here in Homer, Alaska signs of fall are all around us. Leaves are changing color, fireweed and cottonwood seeds are in the air, the temperature is dropping, and we hear the calls of sandhill cranes, geese, and other migratory birds overhead.

Many different types of animals participate in seasonal migrations. There are many reasons for migrating. Oftentimes, animals migrate long distances to avoid harsh winter weather and/or to take advantage of food sources that are more available in certain regions during certain seasons. Oftentimes, animals migrate in order to have greater mating and breeding success. All of these reasons apply to animals that migrate to and from the Arctic each year, as well as animals that may migrate near you.

Animals can travel thousands of miles during migration. Arctic terns hold the current record for long-distance migration, traveling from the Arctic to the Antarctic and back every year. They breed in the Arctic and sub-Arctic areas of North America, Greenland, Iceland, Europe and Russia and migrate to South America, Australia, New Zealand, and even Antarctica. This yearly migration is approximately 25,000 miles, and one Arctic tern was actually tracked flying 59,650 miles in a year!

Read more about Arctic terns on this page from the Cornell Lab or in this article from National Geographic. Though the birds don’t always follow the straightest course, they tend to follow wind patterns which allows them to cover such staggeringly great distances. An extra cool fact: these birds can live about 30 years, and fly this migration route each year. If you add it all up, this comes up to about 1.5 million miles, or the equivalent of three trips to the moon and back!

Terns fly over the water, but many marine mammals migrate too. Beluga whales and bowhead whales, for example, migrate south as winter comes to the Arctic. This allows them to stay in the area near the ice edge, where it is easier for them to move through areas of open water or moderate sea ice concentrations. As the sea ice retreats in the spring, the whales move northward. These migratory patterns help them to avoid the danger of getting stuck in the ice during the winter while also being able to take advantage of the rich food sources available in the Arctic ocean during the summer months. Check out this article from the National Park Service for a great animation of beluga whale migration patterns and discussion of how beluga whale migration is affected by climate change.

On land, caribou also migrate across thousands of miles. Their migration may seem short compared to Arctic terns, but it is the longest recorded terrestrial migration. In northwest Alaska, caribou have been documented traveling 2,737 miles per year. This distance might be greater in other parts of the Arctic. In addition to seeking out different food sources as they become available, the seasonal migration helps caribou to avoid predation, especially during calving season. Click on this article from the National Park Service to learn more about caribou migration in northwestern Alaska and how Indigenous people have built their hunting practices around the migration patterns.

Migration doesn’t just take place in the Arctic, though. Animals migrate all over this vast planet! Think about where you live. Do animals migrate to that place for breeding season or feeding? Do animals migrate through that place from one area to another?

Education Extension

I've compiled a number of science, art, nature observation, and community-based monitoring activity ideas in the Seasonal Migration installment of "Arctic Connection: Linking Your Place to the MOSAiC Expedition." It also includes links to cool lessons for older students focused on real data based on animal migration and tracking and some great short films about migration. Check them out by clicking here!