
Those black "slashes" at 40-50Khz are the bat calling. I was surprised to capture it since they are ultrasonic, well outside the range of human hearing and the microphones supposed limits. Sure, you can buy ultrasonic microphones that are designed to capture bat sounds but this was a cheap pair of regular microphones (Studio Projects C4 cardiods).
The five dark lines at just below 5khz are a cricket calling.
When I slowed the call down 90%, it gets into the range that you can hear it swoop down towards the microphone and away again.
Remember, this is slowed down 90%. There are actually ~7 chips per second on the real recording at normal speed.
At another spot in the recording, it rapidly accelerates its call (maybe to home in on an insect?) -
Nothing earth shattering. I just thought it was cool to have caught that with relatively cheap, non-specialized gear.