Recordings of the low grunts of a vervet who spotted an eagle led other vervets to look up into the sky; recordings of the high-pitched chutters emitted by a vervet upon noticing a python caused them to scan the ground.

一只长尾黑颚猴发现一只发出低沉的咕哝声，记录其他长尾黑颚猴抬头仰的声音。长尾黑颚猴在注意到蟒蛇发出高音调的叫声，记录了它们扫描地面的情况。