The 'dawn chorus' or most birdsong is not as prevalent out of pre- and mating season. I suppose it fits that those birds that sung in the night will not be as noisy out of season either? Are they quieter and not so vocal in daytime too now therefore?

Perhaps, once they have their nests, they are not as loud as it uses energy they need for other things and also keeps down attracting predators?

Not sure at all my maybe a resident ornithologists could comment?

mp