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.

一只长发现一只老鹰时发出低沉的咕哝声，记录其他长抬头仰望天空的声音。长在注意到蟒蛇时发出高音调的叫声，记录了它们扫描地面的情况。