At the height of summer, the sun never sets, 盛夏的太阳从不落山

209. which is why little auks have kept the ability to fly.
     所以小海雀仍然需要保持飞行能力
210. They use scree slopes to protect their eggs,
     它们利用岩肖山坡保护鸟蛋
211. burrowing up to a metre beneath the rocks.
     蛋藏在岩石下的深达1米的缝隙里
212. At the height of summer, the sun never sets,
     盛夏的太阳从不落山
213. but just skims the horizon before rising again.
     只是滑落在地平线上 再次升起
214. Migrants return to the Arctic from far and wide.
     候鸟们从世界各地返回北极
215. They've come to make the most of the brief flush of food and to produce their young.
     它们来寻找美食和繁衍后代

来自《行星地球 第一季 第六集 Planet Earth S01E06 冰雪世界》第 212 行