Birds on the Move

  The exact reason as to why birds pick up, group up, and fly off in the winter only to come back as soon as spring rolls around is unknown. However according to http://www.naturia.per.sg/buloh/birds/migration.htm, scientists have come up with the simple explanation that these large flocks of birds are on the move in search of a good food supply and a safe, slightly warmer enviroment to breed. Studies have shown that birds which breed in the summer months in the north such as the Arctic have the benefits of a large food supply like plants and insects.

   Migration is affected by many different things such as food supply, wind currents, and ocean currents. Wind and ocean currents make some migration routes easier to navigate than others. Most birds move from their summer northern breeding grounds to more southern breeding grounds in the winter. This is because there is more land therefore there is more space for breeding in the north. However, there are other migration patterns. Birds living in South Africa , Australia, and Africa actually migrate to northern grounds for the winter. Oother types of birds have a horizontal migration route. They migrate this way to enjoy the mild coastal climates for the winter months. Some birds even take migration routes according to altitude by moving higher up on a mountain in summer and going to the low lands in the winter.

   Birds are able to fly such a long way when they migrate by using the wind to their advantage. They fly in the same direction so the wind "carries" them to wear they need to go. By doing thise the birds save energy and time which is benefical for survival. Birds change altitude so they can find the best "conveyor belt" of wind to move them along. Larger birds use thermals aka hot air that rises from the ground in the morning to gain altitude by soaring. Those types of birds usually migrate during the day. Not many types of birds fly the whole way without stopping. They rest at staging posts to get some rest and gain enough energy to continue the trip.

  You're probably womdering how birds just know where they're going. Studies have shown that birds use the sun's postion  during the day and the postions of the stars at night as compass points. Birds also can sense magnetic north instictively. They can even use things in nature such as sights, sounds, and smells to find their way. The amazing thing about birds just knowing their way is that the correct route seems to be wired into their brains from birth. Parent birds leave their young behind when they migrate, but somehow most of the time the young birds end up finding their way and finding their parents. It turns out that birds are actually pretty smart animals.