Bloody nesting birds!

[babaduck]

I like them, but not when they're trying to build a feckin' nest above my window upstairs!

There's a ledge about 1 inch deep & they keep congregating there with piles of muck etc. Short of scraping out the area on a daily basis, is there anything else I can do to "deter" them??

 

[ted]

I've a few bin liners tucked into the fascia board and it's doing the trick