Animals migrate thousands of miles primarily to find better resources, such as food or a suitable environment for breeding and raising their young. They navigate these long journeys using a combination of innate instincts and environmental cues.
Why Animals Migrate
Animals migrate for two main reasons: to find food and to reproduce. Many species move to warmer climates to escape harsh winters where food sources become scarce. For example, wildebeest follow the rains across the African savanna to find fresh grass, and humpback whales travel to warm tropical waters to give birth and raise their calves. In their summer feeding grounds, they can find plentiful food, while the warm wintering grounds are safer for their young.
How Animals Navigate
To successfully complete these long-distance travels, animals use a variety of sophisticated navigation methods, often in combination.
- Celestial Navigation: Many animals, particularly birds, use the position of the sun during the day and the stars at night as a compass. They use an internal clock to account for the sun’s movement across the sky.
- Earth’s Magnetic Field: Some animals, including sea turtles, salmon, and many birds, can sense the Earth’s magnetic field and use it to determine their position and direction. This “magnetoreception” is a powerful tool for navigation, especially over long distances or when the sky is overcast.
- Landmarks and Olfaction: Animals like caribou and whales use familiar landmarks, such as mountain ranges, coastlines, or the shape of the ocean floor, to guide their way.8 They may also use their sense of smell to follow scents, with salmon, for example, using scent to return to the exact stream where they were born.
- Collective Navigation: Some species travel in groups, using collective knowledge and social cues to navigate.10 The group’s leaders may possess experience and memory of the route, while the larger group can correct for individual errors, ensuring the entire population reaches its destination.
