Biomechanical study of crow especially, visual, vocal sound, memory and learning

研究了乌鸦（Curves macrorhynchos）的发声情况。嗓音体征分为五类。一是第一步预警，二是第二步（称为A），三是第三步战呼（称为B）。另外两种是爱的呼唤和喂养的呼唤。声音周期范围为 **00 ~ 10000 Hz。然而，强波位于2000 - 3000 Hz。第一次报警声的声波较其他报警声长，当报警情况变得更危急时，重复声的间隔变短，声波周期为1000 ~ 2000 Hz。在这种情况下，乌鸦的行为用咬树的分支作特殊的标志，爱叫爱唱，声音很轻。公乌鸦发出这种声音后，母乌鸦发出类似的声音，而且声音更轻。他们互相重复。这种情况的声波在语音分析仪中位于6000 Hz。

Vocal sin was investigated in crow (Curves macrorhynchos). Vocal signs were determined five categories. One was first step of warning, second step (called A) and third steps warring call (called B). Another two were love call and feeding call. Sound cycle rang was **00〜10,000Hz. However, strong waves were located in 2000〜3000 Hz. Sound waves of First warning voice were longer than that of other warning voice.When Warning condition become to more critical situation, interval of repeated voice was getting short and voice wave cycle was 1,000〜2,000Hz. In this situation, crows behavior makes special sign with bite tree branch around crow.Love call sings were very light voice. After male crow makes such sound, female crow makes similar and more lightly sounds. They repeat each other. Sound wave of this condition located at 6000Hz in the voice analyzer.