Scientists believe that migratory species use a variety of factors to make their way from one place to another. By using the position of the sun and the stars, and by taking note of and following natural landmarks such as rivers and mountains, species are able to make the journey to the same area year after year.
Sense of smell has proven to be important for fish, and recently scientists identified special light-sensitive cells in the monarch butterfly’s antennae that aid in direction. Sea turtles are able to detect the direction and intensity of the Earth’s magnetic field, and scientists have found crystals of magnetic iron oxide in birds’ bills, suggesting that birds respond to magnetic fields, too.
