Two or three years ago, my strata council (of which I'm a member) received a written message from, presumably, a nearby building. The unisgned note was taped to the inside of a window in our entryway, and waxed quite wroth in a whiny, faux-concerned way about our alleged failure to remove out-of-date seagull nests from our roof.
The note explained that the gulls *always* return to last year's nest if it's still around. I suppose that's true, at least some of the time, but unless you're doing careful gull observation like the people who can distinguish individual orcas at a glance, it seems a hard argument to prove in a specific instance. There's a LOT of buyer competition in the gull-domicile market, and Darwin suggests the smart ones plop down wherever the hell they can.
In addition to which, the previous fall, we'd replaced our aged BUR roof with a nice new one, so not only were any old-nest remnants gone, most evidence of prior avian indwelling had been removed, with the remnants entombed by subsurfacing and torch-on roofing.
[One of the roofing guys did tell me that they've "always managed" to clear away debris before it could ever be a nest. And he would know.]