This is a bird that I encounter quite a lot on my travels. It is a common(ish) bird of Sri Lanka as well as here in Cape Town.  In the harbour, not far from where I am staying, you can always see them. They occupy the roof of the Nelson Mandela Gateway Building and from there they dive in to the harbour to either bathe or fish. They seem to bring food back in to the roof of the building and could even, quite possibly be breeding there. I believe that they breed on Robben Island and are numerous there also. We will be travelling there tomorrow so it will be good to see them.  I took numerous photographs of this species yesterday afternoon and early evening, trying very hard to get shots of them as they entered the water, with varying degrees of success.

I was hoping for some really magical photographs of these birds but found it so difficult to focus on them as they entered the water.   In the one below, I think the bird is just dunking in to bathe with it's head turned on the side.