I took this picture of a (white-throated) kingfisher at a cafe - shown below - by the side of the Bentota river.
Actually there is more to it: these birds do not often sit still and are easily scared off. So I ended up with a lot of blurred images and some with just a wingtip moving out of the frame - or no sign of anything feathered at all! The shot at the top might well have been attempt 17 or 23. Eventually, however, the bird stayed in position for a while and I was able to get some further decent pictures.
My wife and I have been to Sri Lanka many times and we generally base ourselves in the South-West of the island. The area around the mouth of the Bentota river is particularly attractive. A bend in the river creates a long peninsula and the beach there is often almost deserted, especially towards its northern end.
There are lots of different types of birds in the area.
The river itself is also one of our favourite locations for a boat safari.
In addition to birds you will come across a variety of reptiles.
There are other interesting sights along the river banks, too - such as this enormous Buddha statue.
The guys piloting the boats know the area very well and will generally do their utmost to show you the things you are interested in.
A piece of advice in this context: when you hire a boat, you pay according to the duration—NOT according to the number of people involved. The boats can generally carry up to 9 passengers and we usually invite local friends along.