Summary task 2 : Bird Migration
A great deal of the birds carry out the migration in every year as long as warm season because the best circumstance can be achieved for laying egg and feeding their cub. The bird migration occurs two times in a year, in the spring and the autumn. During the breeding period, most birds traverse the Northern Hemisphere having higher latitude. Afterward they turn back to the Southern Hemisphere. However, some birds do not conduct a distant migration, as they prefer to breed in the high place. During migration season, the numerous birds travel across the several hundred miles about eight hours a day as the maximum flight time. They use their fat accumulated to be a lot of flesh in the body for meeting the energy need during migratory period. The migratory birds have a natural ability to be the remarkable navigators and intuitive sense of direction.