The Arctic tern covers some 70,000 km a year between the poles, the longest migration of any animal, and by chasing summer in both hemispheres it spends almost its entire life in daylight. Every species follows a route of its own and navigates in its own way. The monarch is the strangest case of all: no single butterfly completes the round trip, and the return leg is finished by three or four successive generations. Flying in a V formation saves the whole flock 20 to 30% of the effort.
The Arctic tern covers some 70,000 km a year between the poles, the longest migration of any animal, and by chasing summer in both hemispheres it spends almost its entire life in daylight. Every species follows a route of its own and navigates in its own way. The monarch is the strangest case of all: no single butterfly completes the round trip, and the return leg is finished by three or four successive generations. Flying in a V formation saves the whole flock 20 to 30% of the effort.
Related topics in Living World