字幕表 動画を再生する 英語字幕をプリント [music] Hi there. I was just looking at my Texas Coastal Birding Trail map. Did you know that the Texas coast is one of the hot spots for birding in the whole country? Every year, hundreds of millions of birds migrate through Texas. And if you stop to think about it, migration is one of the real mysteries of nature. For example, the ruby-throated hummingbird may fly 600 miles, 26 hours, non-stop across the Gulf of Mexico and end up in the same place each year. How do they stay on course and manage such long flights? Some studies have shown that hummingbirds and hawks travel by day, using the sun, rivers, mountain ranges and coastlines to guide them. Songbirds migrate by night, using the stars and the earth’s magnetic field as a compass. Now how birds sense this magnetism is still a mystery. Possibly it’s the tiny mineral crystals in their heads that help them navigate. Making these long journeys is dangerous. Less than half the birds that start out make it back. So birds have developed different adaptations to help them navigate. Some birds wait for tailwinds and select the best altitude to help them fly. Hawks hop thermals to save energy. They fly in an upward spiral on warm wind tunnels called “thermals.” Once at the top, they glide to the next thermal. Geese fly in a V-shape to reduce wind resistance on the flock. Songbirds depend on cooler evening temperatures to prevent overheating. And hummingbirds almost double their weight with stores of fat to provide energy for their long flight. Migrating birds depend on good habitat all along the way to rest and eat. People from all over the world gather at these prime birdwatching areas. It's a keen reminder that we must maintain good habitat, especially wetlands, for both resident and migrating birds. We still have a lot to learn about the mystery of bird migration. Hey, maybe calling someone a birdbrain is actually a compliment! [music]
B2 中上級 野鳥の回遊 - テキサス州の公園と野生動物 [公式] (Bird Migration - Texas Parks and Wildlife [Official]) 1932 89 Mark Lin に公開 2021 年 01 月 14 日 シェア シェア 保存 報告 動画の中の単語