On Nick Yatsko's excellent field trip to Charleston Slough on 3/18/17 there weren't nearly the quantities of ducks as I would have expected, but we did record at least 64 species of birds. Just before we quit we had great views of a Wilson's Snipe. While everyone was getting a look through the Questar, it occurred to me to ask, " Why are Wilson's Snipes always sleeping?" Nobody said anything. Perhaps they didn't want to emphasize my ignorance.
When I got home I looked through all of my bird books. Finally in that great bird book, "The Shorebird Guide", I found the reference, "... crepuscular ... foraging ...at dawn and dusk."