What hawks see

These redtails are all over the place in the winter. I’m not sure if it’s just that they’re easier to see when the leaves are down, or if they come out of the deeper woods in winter as I’ve read.

I’ve wondered before: what makes them choose a given perch? Do they see evidence of mice, and simply wait for an opportunity? Or is it more random?

Today on a walk in the park I saw what looked like veins under the snow: mouse tunnels become visible as the upper layer of snow melts? That’s my guess.