Bird sound speaker at the train station

I was in the station when I heard this amazing bird sound; it was not familiar to me, so I walked around, trying to tune in and listen more. I found a place where the noise seemed louder, and listened for a while before realising the sound was strangely repetitive... I looked up to discover that there was a speaker above my head playing the sound. Not sure what the original bird call is, nor why it is playing in the Komaba Todai-mae station, but I thought this was an interesting feature of the Tokyo soundscape.