Animal migration is the regular movement of animals between regions, often across continents or oceans, to find food, reproduce, avoid harsh weather, or complete a life cycle. These journeys can be thousands of kilometers long and may cross mountains, deserts, rivers, and open seas. Migration matters because it connects ecosystems, moves nutrients, spreads energy through food webs, and helps species survive seasonal change.
Key Facts
- Migration is a repeated seasonal movement, not a random wandering pattern.
- Speed = distance / time, so an animal traveling 3,000 km in 30 days averages 100 km/day.
- Arctic terns can travel about 70,000 km in a year between Arctic and Antarctic regions.
- Sea turtles and some birds can detect Earth’s magnetic field and use it as a map or compass.
- Salmon use smell to recognize the chemical signature of their home stream.
- Monarch butterflies use the Sun’s position and an internal clock to keep a southward or northward direction.
Vocabulary
- Migration
- Migration is the regular long-distance movement of animals between habitats, usually linked to seasons, food, or reproduction.
- Magnetoreception
- Magnetoreception is the ability of an animal to sense Earth’s magnetic field for navigation.
- Compass cue
- A compass cue is a signal, such as the Sun, stars, or magnetic field, that helps an animal maintain direction.
- Imprinting
- Imprinting is a learning process in which a young animal records important information, such as the scent of its birthplace.
- Flyway
- A flyway is a major migration route used by many birds as they travel between breeding and wintering areas.
Common Mistakes to Avoid
- Confusing migration with daily movement is wrong because migration usually follows a seasonal pattern over long distances and connects different habitats.
- Assuming animals use only one navigation cue is wrong because many migrants combine magnetic fields, sunlight, stars, landmarks, smells, and learned routes.
- Thinking every individual completes the whole journey is wrong because some migrations occur across generations, such as monarch butterflies traveling in stages.
- Ignoring energy costs is wrong because migration depends on stored fat, feeding stops, wind, currents, and avoiding barriers like deserts or mountains.
Practice Questions
- 1 An Arctic tern travels 14,000 km in 40 days. What is its average distance traveled per day?
- 2 A herd of wildebeest moves 1,200 km in a year. If it travels mainly during 60 migration days, what is its average speed in km/day during those travel days?
- 3 Explain how a salmon returning from the ocean to its home river could use both a broad navigation cue and a local navigation cue.