fly. The heaviest flying bird alive today, the Kori bustard, weighs 30 pounds or so and flies with difficulty. Albatrosses, for all their wingspread, are lighter, weighing perhaps no more than 22 pounds, and they have difficulty taking off. They spend most of their time in the air soaring, rather than actively flying, taking advantage of rising air currents rather than their wing muscles.The ...
weigh as much as 40 pounds, 20 times that of the largest bat. At that weight, however, in can just barely fly. Some albatrosses, which are not quite that heavy, have the widest wing spread--up to 10 feet.The pterosaurs has membranous wings like the bat, but whereas,in bats, the membrane stretch over all the fingers but the thumb, the pterosaurs' membrane was attached to a vastly overgrown ...
동아사이언스
디라이브러리
DS스토어
팝콘플래닛
