It's the largest breeding colony in North America. 是北美最大的繁殖地

228. These hypersaline waters keep many predators at bay...
     这种高盐度的水使很多捕食者望而却步
229. ..so it's here they choose to nest.
     因此它们选择在这里筑巢
230. There are more than 10,000 pairs here.
     这里有着 10,000 多对火烈鸟
231. It's the largest breeding colony in North America.
     是北美最大的繁殖地
232. Nest mounds keep chicks clear of the brine
     巢穴的土丘使脆弱的雏鸟
233. while they are still at their most vulnerable.
     得以远离咸水
234. But this generation faces a problem.
     但这一代火烈鸟面临一个问题

来自《行星地球 第三季 第一集 Planet Earth S03E01 海岸》第 231 行