seasonal migration

基本解释

We are accompanied by guides armed with flash pistols and hunting rifles, scanning the snowfields for polar bears for whom this is a seasonal migration route.
陪同我们到来的向导带着信号枪和猎枪，他们在雪地上搜寻着北极熊的踪迹，这里正处在北极熊季节性迁移的路线上。
Bird banding is one of the important means to research the seasonal migration of birds, and is an effective method in researching the faunas, ecology and morphology of birds.
环志是研究鸟类季节性迁徙的重要手段之一，同时也是研究鸟类区系、生态学、形态分类学等的有效方法。
Their lifestyle is semi-nomadic, and the movements are somewhat seasonal, having to do with the migration of some prey animals, and the gathering of certain plants and fruits.
他们的生活方式类似于半游牧，而且甚至还跟猎物迁徙和特定果实的成熟季节有关)。

Remoteness and seasonal migration for work are others.
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