Breeding season is long gone and most wading birds have left the swamps. Food is more plentiful in the marshes.
This happens every summer and photography gets to be more like work at times. Shooting in the swamps is a close environment, you know where everything is and presto… they are always there.

Now you have to go to a marsh, walk out in the open heat, and go find them.
Above is a Great Blue found near where a river feeds old rice fields and marshes. Very different scenery compared to the rookeries.

Mud plays a big part. Oh yeah, there are more insects that bite in marshes.