From my personal experience the Black-crested Bul Bul is most wary of human presence. At the first sign of human presence these 'shy' birds of the extensive Bul Bul family would skuttle away. Many a time opportunities to photograph and record these otherwise elegant-looking specie with pitch black feathers for it's crest and bright - almost flourescent yellow for most parts of it's body and wings are lost. Once sighted one have to sneak-up to stand a chance to watch/photograph them before they fly away. :-)
This specie could be found in broadleaved forest at approx 2600 ft above sea level. It could be seen in a small flock of 3 - 4 or at times as part of a 'bird wave' sweeping through an area whilst feeding. The next time you are out birding in a montane region keep a special look out for them. Good luck!
Here are a few pictures for sharing.
Thanks for dropping by. Cheers!