Geese migrate to avoid the harsh arctic winters at their northern winter nesting grounds. Temperatures regularly drop to below -20°F (-30°C) during winter in the arctic, so geese have to fly south to find food.
Although most geese migrate, there are large populations of geese who don’t migrate at all because their nesting sites are far enough south that they can survive year-round.
In this article, we’ll look at the conditions that cause geese to migrate, and look at some goose populations that don’t migrate and how they do it.
Why Do Geese Migrate?
Geese migrate because the weather in their northern arctic nesting grounds makes it impossible for them to stay there during the winter months.
Here are some of the problems the climate creates that compel geese to migrate…
1. Insufficient Food
Geese have a diet that consists mainly of different kinds of plants (including aquatic plants) and small creatures such as snails and insects.
During winter, the water in the lakes, rivers, and seas where geese nest freeze over, plants die, and the ground freezes solid, totally cutting geese off from their supply of food.
2. Breeding Ground
Although we often think of geese migration in terms of North to South, it’s important to remember that they also make the return journey every spring, choosing to spend their winters in the far north.
After the worst of winter is over, geese make the long journey north again to return to their ancestral nesting grounds. This is because there are considerably fewer predators there than there are in the warm southern regions where they spend the winter.
Geese’s breeding season begins in late spring, so they arrive to an arctic teeming with life, a plentiful food supply, and a lack of predators, making it a perfect place for them to make their nests and lay their eggs.
3. Uninhabitable Cold
For those geese that make their nests above the arctic circle, temperatures in the winter are simply be too cold for geese to survive, forcing them to move south each autumn.
Though their feathers provide a layer of insulation, geese can still freeze to death or suffer injuries like frostbite in extreme cold.
Temperatures regularly reach -20°F (-30°C) in Northern Canada (where they also nest in spring), which leaves geese with no choice but to migrate south for the winter.
Read More: How Far South can Canada Geese Migrate?
Why Don’t Geese Just Stay In One Place?
Geese choose to migrate because they need the safety of their northern nesting spots in the summer to breed, and they need the abundance of food and more comfortable weather of their overwinter spots during winter.
Some populations of geese do stay in one place for the whole year. If the climate is suitable and they have a steady supply of food and an absence of predators, but geese are notorious for depleting their own food source rapidly, so these conditions don’t exist everywhere.
In recent years, climate change has been wreaking havoc with all bird migratory patterns, including geese. Geese are missing the signals they look out for in winter to signal the incoming cold, and causing year-round populations to be evident further north than they were before.
Why Don’t Geese Hibernate Instead of Migrating?
Birds can’t hibernate because their metabolism is too fast and they don’t have enough fat reserves. This is the same for all birds, including other waterfowl like Swans and Ducks.
Read More: Geese vs Ducks – What’s The Difference?
Geese have evolved to be able to migrate to avoid the cold weather conditions. Some species can enter a low-energy state called torpor, but it’s not full hibernation.
Read More: Can Geese Hibernate?
Do Geese Need To Migrate?
Geese need to keep moving whether they migrate or not, because their large flocks deplete the food in any given area over time. Some populations don’t make a full migration every year because they live in an area with mild winters and ample food.
With temperatures changing due to climate change, the behavior of geese is also changing. Geese are found to be staying in one area for the whole year further north than they had been before, as their nesting spots aren’t getting as cold as they were before.
Perhaps, in the future, we may even see geese staying inside the arctic circle all year round.
Geese migrate because they need to escape the harsh winter. Geese that live in the far north would freeze to death and starve if they didn’t migrate.
Geese fly north to find a safe place to make their nests and breed, but they can’t stay there over the winter because their food supply is killed off by the freezing temperatures.
Geese need to migrate now, but due to changing climates, some year-round populations of geese are being found further north than was previously possible.
Stuart is the editor of Fauna Facts. He edits our writers’ work as well as contributing his own content. Stuart is passionate about sustainable farming and animal welfare and has written extensively on cows and geese for the site.