Bar-tailed godwits breed in Alaska, and when it begins to get cold, they move to Australia or New Zealand located in the Southern Hemisphere and get through warm winter. In order to fly from Alaska to their destination, they have to cross the Pacific Ocean; surprisingly, the bar-tailed godwits fly nonstop over that long distance.
Having doubts about whether they rest on an island in the Pacific Ocean, ornithologists of the United States Geological Survey put a satellite tracking device on some of the bar-tailed godwits to find out their flight route. As a result, they noticed that one of the birds left Alaska in the afternoon of August 30, 2007, and arrived at the mouth of the Piako River in New Zealand in the evening of September 7, 2007. It did not stop at all, flying about 11,700 kilometers [7,270 miles] for eight full days. How is that possible?
Before their migration, bar-tailed godwits focus on eating to save as much fat as possible. Fat refers to fuel of airplane, and the birds should become fat enough to fly a long distance. Because of fat, their weight increases two to three times, but their liver, kidney, and other organs that are not much involved in flight are reduced in size.
Bar-tailed godwits prepare for their flight thoroughly, even by changing their body structure. This is the power that enables them to fly about 11,700 kilometers [7,270 miles].