Who is making this noise?

On Thursday night we had the most tremendous sightings of the Aurero borialias, Northern Lights. I only had my tablet so I could not get any photos, just a black screen but I took this recording. There were a number of birds circling right over my head, they either stopped makings a noise for a brief moment or settled but this was one that came round on it's own.

Oops need to sort out how to add the video.