Strange rooster behavior

[BeginnerChickener]

My about two year old hy-line brown rooster has started throwing crowing fits in the middle of the night, last night he crowed non-stop from about 2am till 3am, what could be causing this? These incidents are irregular, theh happen maybe once in two weeks. A fox has been visiting our neighbour’s house, could it be making my rooster nervous? This is my chonky boy in the picture

 

[Folly's place]

He's crowing because something is disturbing him then. Could be a visiting critter, lights from the road, something. Could you set up a game camera or two? Might be interesting.
Mary