Commensalism: Wood Stork and herons cooperate

In late afternoon I looked out the back window and saw a Wood Stork on the lawn of the small park diagonally across our lake. Its wings were fully extended, probably drying off after a brief downpour. By the time I got my camera, the stork had partially closed its wings. 



Next to the stork, an immature Tricolored Heron also rested and preened. 



Suddenly a Great Egret flew in and settled at the edge of the water near the heron. Both started running to the right and the stork rushed over to join them. 



I could see the water was disturbed by a school of small fish. The trio began feeding together, and they moved further down the shoreline. 



Then the egret seemed to see another school of fish back the other way. Both herons took flight, with the stork running along behind them. 





Again they fished together... 



...until once again they relocated to the edge of the lake immediately in back of our home. They were so close that I could not fit them all in a single frame with my 420 mm f/5.6 telephoto lens system, but I got some good shots when they passed along in front of me as I stood on the patio. 

The Tricolored Heron led the charge excitedly, the feathers on its head erect.





The stork and egret were close behind.





The egret watched, ready to pounce on any fish that appeared as the stork shaded the surface and stirred the water.



As before, the egret sighted another school back where they had previously been fishing, and the trio flew over there. 



I believe this is an example of commensalism, with all three species deriving mutual benefit of the others-- the sharp vision of the herons helped find the prey and the stork stirred the water with its foot as it probed, driving the fish out of hiding and thus aiding the herons. 

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