Common Grass Yellow Butterfly

I took this picture when I was at Meru Betiri National Park.. There is little path to the boardwalk, with grass on the side, close to the camping ground at Sukamade. So many butterfly over there.. I was wondering to see the Peregrine Falcon on the sticky wood forest, which is I saw it few years ago before..
I think I saw a Cooper Smith Barbet.. But I couldn't get the picture.