He sounds the alarm, 雄性水雉发出警报

88. ..his chicks not only double in size...
    雏鸟不仅个头长大了一倍
89. ..they grow in confidence.
    信心也增加了一倍
90. But this is a dangerous place to stray.
    但这里其实危机四伏
91. He sounds the alarm,
    雄性水雉发出警报
92. and his chicks instantly freeze.
    雏鸟便立刻停了下来
93. They can't yet fly to safety.
    可它们还无法飞离险地
94. But there is one thing he can do to protect them.
    但雄性水雉还有一种手段来保护雏鸟

来自《行星地球 第三季 第四集 Planet Earth S03E04 淡水》第 91 行