For seven months, the dam birds were forced out of their community by severe drought conditions which led the dam idle and halted the availability of the small fish they survive on. Then, with the winter rains, the citizens of the dam returned: egrets great and small, blue herons, terns, gulls.   Some I recognize from last season while others are newcomers. They have established a social hierarchy and chosen their favored fishing spots. After a heavy rain, the raging water of the outflow chutes create intense turbulence and — rainbows.  I am hoping for a long and fruitful season for all of us below the dam. Here are the first of the Dam Birds of 2017.