The Common Jay Butterfly as the name suggests is common and can be found all over South East Asia, the males like mud puddles near streams in forests and tend to gather together.
If you have sour apple, custard apple or avocado in your garden then you will most likely get common jays visiting to lay their eggs.
The Common Jay can have a wingspan of up to 8cm, this one in the photo is just over 6cm.
Graphium doson
Thai Butterflies Main Page.