Most hatchings happen at night. 多数的蛋是在夜间孵化

254. when it'll be safer to visit the beaches.
     这样可以较安全爬上沙滩
255. Eggs that were laid a few weeks ago, at the start of the season
     几周前下的蛋,在这个季节伊始
256. are beginning to hatch.
     开始孵化了
257. Most hatchings happen at night.
     多数的蛋是在夜间孵化
258. Now, in the light of day, the young are extremely vulnerable.
     现在是白天,小海龟们很容易受到攻击
259. They must get to the sea as soon as possible
     它们必须尽快爬向大海
260. but their trials have only just begun.
     不过小海龟的试炼才刚刚开始

来自《行星地球 第一季 第十一集 Planet Earth S01E11 海洋深处》第 257 行