How do I know if a birds nest is abandoned? Or what is it?

I was trying to hack back a duranta hedge to manageable height and discovered this #nest . I pruned around it, not wanting to disturb possible occupants, but also hoping that the missing branches makes it a less appealing site.

That was a few months back. I'd ultimately like to finish the pruning job (but that hedge is non native/semi-invasive, scrawny and already awkward on the ladder)

Probably 4m from the ground so I can't see in. Are nests reused? Can I remove it? Or do i just wait a few years till it rots away? I feel like a 90s cartoon developer-villan!

#BrisbaneGardening #BrisbaneWildlife #birdnest #BrisbaneBirds