okay I found the ruler thingy. The aviary in my photo above is about 33 metres across the end shown in the photo. The aviary isn't straight, but it looks to be about 90 metres long. The smaller aviary looks to be around 29 metres wide and 57 metres long. I really don't trust the measurement tool to be accurate though, especially because the satellite image doesn't show the boundaries of the aviaries clearly. Just for fun I then went to Jurong and got the Lory Loft as something like 53 X 58 metres and the Waterfall Aviary as being 136 X 113 metres (not being precise in the measurements of either, of course).
Nice. I think they may be far more numerous than we might think in nature... Would be nice to have a ex situ breeding population! What other locales have them?