Pidgeon keeps pooing on balcony! Help!

[sarahjsdddd]

Hi all,
Hope this is correct place to post! We live in a flat (moving in the next few months so only need temporary solution really)
Had pigeons trying to build nests on our balcony, we have cleaned all the mess and poo off our balcony and added a wind chime, which seems to have helped but noticed there's a pigeon sitting underneath the balcony above that keeps doing gigantic pops everyday which I am fed up of cleaning!!
The balcony above is pretty high above our balcony so I don't think we could reach up to put a wind chime there (plus the people living there may not appreciate that) is there anything you could advise we do?
Any advice appreciated!

Sticker of a hawk on your window?

I've given up trying to deter pigeons. They won't move till you're within 2m of them, and they're back as soon as your back is turned.

Big plastic owl?

Must be annoying, pigeons are annoying enough in the garden, we have a big ash tree full of them and therefore a lawn full of shite. But a balcony would be worse.