More than likely a bird as you surmised.
Which bird gets more difficult.
Unless you can spot the little blighter, you are stuck to guessing at best.
Depending on part of the day, it could be a mourning dove, or it could be one of several owls.
Or a “Chuck-wills-widow”, yet another nightjar bird that seems to have regional variations in the call it makes.
Here in my area we had one [way far away from where it was supposed to be from what I guess] that sounded like it was saying ‘Wheee-ooo-whee-ooo-wheee-ooo’ instead of the usual noise.
Sounded like a ‘grumpy old lady wrapped in a shawl and muttering’ pretty much.
Common Nighthawks aren’t so common in my area, but whip-poor-wills are.
So when I saw the bird, I initially thought it was a Whip-poor-will.
And then it got bored with me loking at it, and the person with the camera was too annoying in their approach, so it flew off.
A little bit later we heard the “Peent!” and the buzzing noises.
There are so many trees around here that it’s difficult to locate the bird. Then again, there might have been two of them calling to each other. At least I’m starting to recognize the nonvenomous snakes. Do you have a lot of snakes? We seem to be overloaded with them.
Walk like an Egyptian...