The Arctic tern flies 71,000 km (44,000 miles) between the Arctic and Antarctica and back every year, for up to 30 years. Arctic terns migrate to follow the summer sun. Seasons happen because Earth is tilted on its axis while it revolves around the sun. During winter, the Northern Hemisphere is tilted away from the sun’s warming rays. This is why it’s colder during the winter in places north of the Equator, like the United States.
When it’s winter in the Northern Hemisphere, the Southern Hemisphere is tilted toward the sun, experiencing summer. In December, when people in the United States are putting on sweaters and jackets, people in Argentina are getting out their sunscreen.
Polar Regions experience less noticeable temperature changes than other parts of the globe. However, these regions experience a great difference in the amount of daylight hours. During summer, the Arctic and the Antarctic get almost 24 hours of sunlight. During winter, it is almost entirely dark.
The arctic tern, going from Arctic summer to Antarctic summer, may experience more daylight than any other animal. Terns migrate in search of summer sunlight. Sunlight illuminates the ground and the ocean surface, so the birds can see fish or insects more clearly. Summer weather is also usually calmer at sea, allowing the birds to fly more easily.
Picture Credit : Google
