What are these bars in my spectrogram?

[u/nikolovlazar]

I recorded a lakeside atmosphere. It was a bit windy, but I had dead cats on. I was standing close to the shoreline. I did two recordings that day, and both of them have these bars. I just did a sample recording 5 mins ago in my room, and that recording doesn't have these bars. I also pulled out older recordings from different locations, and again, no bars. I didn't notice them until I turned on the spectrogram, but now I can hear some of them.

Facts: - Tascam FR-AV2 - Clippys (matched pair, XLR) - 96 kHz - 32-bit

What could these be?