Kokkarebellur (Kokrebellur) is drivable distance from Bangalore. Its more like a 1 day trip.
The best time to visit is around Jan-Feb when most of the birds arrive.
Fuel costs: Rs 800 for fuel
Entrance Fee: 0
Grab a local villager as a guide for say 50 rupees
[DO not pay any children there, as you would encourage them to beg]
What to expect:
Lots and lots of painted storks and pelicans concentrated over a few trees.
Park your car and walk around the place for an hour or two.
No eating place at the location. You need to drive back to the Bangalore-Mysore highway to get anything to munch on. To your advantage there are lot of eating options on the highway.
A snippet from Wiki on how to reach this place:
It is at a distance of 83 kilometers (52 mi) from Bangalore on the Bangalore-Mysore highway. The branch road to the village is 12 kilometres (7.5 mi) from the highway at the ‘Coffee day’ land mark, close to Maddur. It is 20 kilometres (12 mi) to the north-east of Mandya. Maddur and Mandya are the closest railway stations on the Mysore-Bangalore broad gauge link.