Geese are often associated with seasonal journeys south for colder months. However, their migratory behavior is more complex; not all geese undertake these extensive travels. Some populations remain in specific locations year-round. This article explores factors driving goose migration and why certain populations have become permanent residents.
The Driving Forces Behind Migration
Goose migration is primarily a response to environmental and biological needs. As northern regions experience decreasing daylight hours and declining temperatures, natural food sources become scarce. Geese are herbivores, relying on grasses, sedges, and aquatic plants, which become inaccessible or covered by snow and ice during winter. The birds instinctively seek areas where foraging opportunities remain plentiful.
Access to open water is another significant factor, as northern lakes and ponds freeze over. Open water provides geese with safety from predators and suitable roosting sites. Geese also migrate to reach appropriate breeding grounds where conditions are optimal for raising their young. They build substantial fat reserves before their journeys, which provide the necessary energy for long flights without consistent access to food.
Navigating the Journey South
Geese use a combination of environmental cues for migratory flights, including the Earth’s magnetic field, the sun and stars, and familiar landmarks like coastlines and rivers. This allows them to follow established routes, often called flyways, such as the Atlantic, Mississippi, Central, and Pacific Flyways in North America.
Fall migration begins in late September or October, continuing into November, as temperatures drop in northern breeding grounds. Geese fly in a V-formation, which reduces wind resistance and conserves energy for the flock. Their journeys can span thousands of miles, with some Canada geese traveling between 1,000 and 2,500 miles. Along these routes, they use traditional staging areas to rest and feed, replenishing energy before continuing.
Resident Geese and Changing Habits
While many geese continue annual migrations, a growing number have become “resident,” opting not to fly south. This shift is influenced by human-altered environments. Urban and suburban areas provide abundant, year-round food sources, such as manicured lawns in parks and golf courses, and waste grains in agricultural fields. These food supplies reduce the need for geese to undertake migratory journeys.
Milder winters contribute to geese staying put, as open water sources may remain unfrozen. Developed areas have fewer natural predators and reduced hunting pressure compared to wilder landscapes. Some resident populations are descendants of captive-bred geese that were released and never developed the migratory instinct. These factors allow resident geese to thrive, leading to increased local populations.