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.

一尾黑颚猴发现一老鹰时发出低沉的咕哝声，记录其他尾黑颚猴抬头仰望天空的声音。尾黑颚猴到蟒蛇时发出高音调的叫声，记录了它们扫描地面的情况。