Well, I dont think these hornbills here are disturbed by people as their nests are just right above the food centres area . There are heavy traffic, buses, noise pollution, people sitting below, smokers, loud noises. If they had want to abandon their nest, they would hav done it and hide in the jungles or Ubin to do so.
I am sure many of the customers below at the food areas, see these birds all the time and who knows god forbid, maybe had done worst thing.
We photographers are more responsible people, who knows the need to preserve nature and its environment and I believe would be more discreet in our actions I hope.