Why does some birds migrate and others don ?
1) “In fact, some have suggested that the question should be why don’t all birds migrate. Flight gives birds a huge advantage in finding new sources of food and good places to breed, that it is strange that not more birds migrate.” “All kinds of birds migrate, from large cranes, birds of prey, to tiny hummingbirds. Even flightless birds migrate! Emus move from breeding sites in the rainy season to more permanent water sources in the dry. Penguins migrate in the ocean. Auk babies migrate by swimming until they fledge and can fly! Even birds that spend their entire non-breeding time in flight, such as seagulls, also move around on the ocean to follow seasonal food abundances.” Source and further information: http://www.naturia.per.sg/buloh/birds/migration.htm 2) “Q:Why do about 520 of the 650 bird species that nest in the United States migrate south for the winter? A:Because they would freeze
