Flamingos

WMZ uses mirrors to fool the birds into thinking there are more in the enclosure

That makes so much sense and I'm suprised it's not a more popular solution. Does anyone know anywhere else that does this?

I believe Seaview Wildlife Encounter on the Isle of Wight claimed to be the first to use this technique, there was quite a lot of press coverage when it started.

I've seen it in a few zoos, Edinburgh being another one.

Yes Seaview wildlife encounter used it to get their Carribeans to breed this resulted in egg laying but only 2 fertile eggs so they gave the nesting carribeans chilean flamingo eggs to hatch out which they happily did. I think the public donated the mirrors.
Colchesters chileans have been given them this year resulting in them nest building,I think the wildfowl and wetlands trust uses them as well.
It does make me mad more zoos don't use them as well as the birds often nest as a result,I have asked Twycross and paradise park to install them.
I think the trick is to put them in the right areas and early in the year.
I think it would work better also if once put up they were cleaned once every few months!