Weird Birdsong

I woke up last Thursday at around 5am and birdsong outside sounded eeriliy unnatural. It cycled repeatedly across four different sounds each lasting 2 seconds. Sometimes there was a break and sometimes several cycles repeated exactly like the others. This sounded artificial as if I were hearing a machine. It continued for well over half an hour and sounded like one bird. If more than one then there would have been asymmetry to the sounds. I could not go back to sleep for that time.

This is like some reports of the eerie sounds sometimes heard in the jungle or countryside. Also, it felt like a jittering of reality somewhat akin to deja-vu (as seen in the Matrix).