There is a small one at my feet today, folding its whole nest into boxes, and I have seen this before, though never quite this one.
I knew it as a seedling. It sat against my trunk with its picture books when the bark was rough enough to catch the fabric of its clothes, and it pressed a hand flat to me one autumn to feel, I think, how wide I was. It carved something near my base with a dull blade three summers ago. I have kept the mark. I keep all of them.
Now it carries the flat boxes out to the metal thing that waits by the road, and it walks a little differently, taller, quicker, the way they do when the sap in them rises toward something I cannot see. The window that faced me all its life is dark by evening.
A square of it goes bare. Behind the glass a shape lingers longer than the others, one of the two big ones that fed it, standing in the emptied room with a hand on the sill, watching the small one load the last of itself.
They do this. They rise so fast, in a handful of my seasons, and then some pull I have never felt draws them off down the road toward light I do not reach, and they do not come back, or they come back changed, larger, with smaller seedlings of their own who press new hands to my bark.
I do not understand leaving. I have never wanted to be anywhere but here.
So I will hold the mark it cut, and let the birds keep nesting, and put on another ring, and be standing in this same patch of ground when it returns, older, to point up at me and find me exactly where it left me.