Postscript 02/12/15: here’s an adult Black-crowned Night Heron at the same location a couple of days later.
The shrimper docks host regular feeding frenzies for a variety of shore birds, mainly Pelicans and Gulls, and some Egrets and Cormorants. It’s a nice spot to get close to some otherwise wary birds. The shrimp boats come back with their catch and they sort out the odd fish from their nets, tossing them out to the gathered crowds of eager birds. Black-crowns can be seen resting by day underneath the restaurant that faces the docks. And sometimes they venture out into the light.