Read an Academic Passage

The Functions of Animal Migration

Animal migration is the long-distance movement of a population, often on a seasonal basis. It is a common phenomenon found in a wide variety of animals, including birds, mammals, insects, and fish. The primary drivers behind this demanding behavior are typically related to survival and reproduction. Animals migrate to find more abundant food resources, to locate more suitable climates, or to seek safe and resource-rich locations for breeding and raising their young. These journeys can span thousands of kilometers and represent a remarkable feat of navigation and endurance.

Navigating these extensive routes is one of the most fascinating aspects of migration. Scientists believe that migrating animals use a combination of cues to find their way. Many birds, for instance, are thought to use the Earth's magnetic field as a sort of internal compass. Others may navigate by the position of the sun during the day and the stars at night. For some species, like salmon, a highly developed sense of smell allows them to pinpoint the exact stream where they were born. The specific mechanisms often vary between species and are still the subject of ongoing research.

Migration, however, is a perilous undertaking. It exposes animals to a host of dangers, including predation, starvation, and extreme weather. The energy required for the journey is immense, and not all individuals survive. Furthermore, human activities such as the construction of dams, buildings, and fences can obstruct migratory routes and destroy critical habitats used as resting stops. The conservation of these routes and habitats is therefore essential for the survival of many of the world's migratory species.