Do birds prefer overcast?

Today's overcast has texture, like a quilt.  The sun slipped through at dawn then disappeared.  Both the creek and the feeder have been active.  Diving ducks, cormorants, pelicans, gulls, and a great blue heron have been fishing.  A white breasted nuthatch joined the regulars and both sparrow species at the feeder.  Two yellow rumped warblers scurried below. 

At lunch, a male towhee joined the sparrows and regulars.  Stuff fell from the sky in little white pellets that melted quickly.  Herons and pelicans kept on hunting fish. The squirrel with the white spot on her hip showed up.  The clouds began to break up in the late afternoon.