This bird, which is a juvenile, was feeding in a textbook location - flooded grassland. The extent of the spots on the neck indicate that this is not an adult bird.
This bird was feeding on frogs (I think) and crickets. You can see one the crickets in caught in the pictures. The bird was also regularly hack up a pellet of undigested material, which suggest to me that crickets are a pretty rough food source.
The bird was on one side of a road feeding in the grass and I was parked on the other side. Unfortunately for me, the bird took a dislike to a passing truck and flew off! Bit of a shame really as it was being rather cooperative!