Bird’s wings generally become shorter and more rounded the closer they live to the equator, according to a new study that may help us better understand how life on Earth has developed. Birds with smaller wings are to a greater extent restricted to stay in the same area, because their wings have not evolved for long distance travel, researchers from University of Copenhagen in Denmark said.
Short round wings have not evolved in order to aid travel over long distances, meaning these birds stay within a relatively restricted area throughout their life. Although it might seem obvious that all birds are capable fliers because they have wings, our results challenge this assumption, said Jonathan Kennedy from the University of Copenhagen. Birds that are found in different parts of the world have very different wing types. In many cases, birds will not fly longs-distances, unless their wings have specifically evolved for it, said Kennedy. Our results provide new knowledge about how species spread across the world and improve our understanding of how life on Earth has evolved, he added.