Bulbul, Black-Headed - Yellow vented

I went to the muzium for a bird sighting after my morning meeting with a friend there. I'm getting lucky to encounter this birds with my lens limited range and from this angle, I cannot determine the exact type of Bulbul birds. From the Gobird app that I install on my phone, there's a sighting of a Yellow-Vented Bulbul here and I think this is the one. The main characteristic of this yellow-vented bulbul the yellow colour of the undertail-coverts. But with this composition and lights condition, that yellow colour is not visible. Getting a sharp photo of it is very hard due to the small branches keep getting in the way and my old Tamron lens just cannot keep up with the latest camera autofocus technology. Thus, this is the only photo that I managed to get.