I took my lunch down to the saltmarsh and ate it there. I saw that it was only a little after noon, so I leaned back for a nap, I knew rhe birds wouldn't be there for a while. At a little past 1:30 PM a Great Egret came sailing in, then a Snowy Egret, and then a Great Blue Heron. I expected them, that was when the tide was going to start to rise. The tide is the clock the shore birds run their lives by, they know, somehow, where to be, and when. It's an accurate clock, but it changes every day. The birds still keep track of it. The rising tide brings food with it.
I keep track of it too, but I have to look at my watch.