Department of Biology, Lund University, Sweden.
Department of Biology, Lund University, Sweden.
Curr Biol. 2018 Sep 10;28(17):R968-R972. doi: 10.1016/j.cub.2018.04.043.
Billions of animals are adapted to a travelling life, making regular return migrations between more or less distant living stations on Earth by swimming, flying, running or walking (Figure 1). Extremely long migrations are completed annually by whales between calving areas in warmer waters and feeding areas at higher latitudes in either hemisphere. The longest oceanic migrations among sea turtles and fish are often undertaken by younger immature individuals during a period of several years before they start their more regular return visits to breeding and spawning sites. Among adult leatherback turtles, intervals of several years between successive breeding events leave enough time for extremely long journeys. Famous among bird migrants are arctic terns, showing the longest known annual migration circuit of about 50,000 km. Bar-tailed godwits breed in Alaska and winter in New Zealand and make the longest known non-stop flapping flights, lasting more than two hundred hours and covering up to 12,000 km across the Pacific Ocean. Their total annual migration circuit extends over 30,000 km covered in three main flights (Figure 1). Although diapause with hibernation as egg, pupae, larvae or adult is an important strategy among insects, there are also examples of impressive migrations. Monarch butterflies complete an annual circuit up to 9,000 km in North America in four generations (for more detail, see the review by Steven Reppert in this issue), and the globe skimmer (a dragonfly) presumably exploits the monsoon rains in India and rainy seasons in southern and equatorial Africa in a 15,000 km circuit in four generations (Figure 1). In comparison with swimmers and flyers, animals that migrate by running or walking cover shorter distances. Caribous migrate between boreal forest and tundra over a total distance of not much more than 1000-2000 km per year. Zebras make the longest migrations in Africa, covering at least 500 km, which is just a little bit longer than the well-known wildebeest migration circuit in Serengeti.
数十亿动物适应了迁徙生活，通过游泳、飞行、奔跑或行走，在地球的远近不同的生活区域之间定期往返迁徙（图 1）。在南半球或北半球的较高纬度的觅食区和更温暖的繁殖区之间，鲸鱼每年都会完成极其漫长的迁徙。在海龟和鱼类中，最远距离的海洋迁徙通常由年幼的未成熟个体在几年的时间里完成，然后它们开始更定期地返回繁殖和产卵地。在成年棱皮龟中，连续繁殖事件之间的间隔时间足以让它们进行极其漫长的旅程。在候鸟中，北极燕鸥最为著名，它们的年度迁徙路线是已知最长的，约为 50000 公里。斑尾塍鹬在阿拉斯加繁殖，在新西兰过冬，它们完成了已知最长的不间断振翅飞行，持续超过 200 小时，跨越太平洋超过 12000 公里。它们的总年度迁徙路线长达 30000 公里，分为三个主要的飞行阶段（图 1）。尽管昆虫的休眠期（如卵、蛹、幼虫或成虫）是一种重要的策略，但也有令人印象深刻的迁徙例子。帝王蝶在北美洲完成了一个长达 9000 公里的年度迁徙，分四代完成（更多细节见本期 Steven Reppert 的综述），而扁石蜻蜓（一种蜻蜓）可能利用了印度的季风降雨和南部和赤道非洲的雨季，在四代中完成了一个长达 15000 公里的迁徙（图 1）。与游泳者和飞行者相比，通过奔跑或行走迁徙的动物覆盖的距离更短。驯鹿在北方森林和苔原之间迁徙，每年总距离不超过 1000-2000 公里。斑马在非洲进行最长的迁徙，覆盖至少 500 公里，略长于著名的塞伦盖蒂角马迁徙路线。
