Driving across town yesterday, I looked up and saw a small flock of white pelicans, probably ten or twelve of them, doing big slow turns as they rode a thermal. The white pelicans come back every year about this time, and the thrill never diminishes. For one thing, they’re enormous — watching a white pelican come in for a landing is like watching a big bomber plane come in — one is always astonished that something that big, and that body-heavy can be as graceful as it is. Years before I moved here, when I was doing my PhD work,…