Bird advice

[BR14]

could be fox cubs, - they make all sorts of squeaks and squeals

[SueEllen]

Most birds that aren't nocturnal will be tucked up asleep when it's dark, they won't make any noise. I'd almost put money on it not being a small bird.
When you say "outside the door" do you mean it's at ground level (or at least not up in a tree), if so it's an animal, not a bird. Owls will only tend to call when up in trees. When they are down low they tend to be hunting, which requires stealth.
It could be a fox.

I hear birds singing and tweeting after midnight in my area. The sound varies due to exactly where I am.

It is also well documented that robins sing at night due to street lights.

[BrilloPad]

Most birds that aren't nocturnal will be tucked up asleep when it's dark, they won't make any noise. I'd almost put money on it not being a small bird.
When you say "outside the door" do you mean it's at ground level (or at least not up in a tree), if so it's an animal, not a bird. Owls will only tend to call when up in trees. When they are down low they tend to be hunting, which requires stealth.
It could be a fox.

I reckon thieves making off with a generator...

[d000hg]

I say just outside the door, but at night things sound that way... I'm fairly sure it's in the tree canopy just a few yards away. It's pretty much every night, late, so for it to be the same spot makes me think something is roosting/living there.

I like having critters around - though this is the least tuneful one I've ever heard - just wondering what it could be. We have wild peacocks around here and they're noisy, tuneless things but none have taken residence in our garden

[RSoles]

Not sure how far south you are, but when I lived in Sussex we had a similar occurrence with a cricket in a nearby tree.
It was around this time of year too.

[Bee]

I hear birds singing and tweeting after midnight in my area. The sound varies due to exactly where I am.

It is also well documented that robins sing at night due to street lights.

Yes, the street light has a lot of influence but they also became alarmed when previewing storms, climate changes, earthquakes, etc...