We have a bird here known incorrectly as the Indian Minor, it actually comes from the South Pacific region.
It is a bit of a terrorist often chasing native ones away.

We had for many years a vacant block next door to us with some 60 small trees on it.
Every night the Minor birds, about 250 or so, would flock there to nest, this went on for about 15 years.

Then the block was sold and the trees removed.
The birds came back that night to find the trees gone.
They spent about 90 minutes flocking around before moving on.
I assume they found some others to nest in.