One night, when I was living in Washington, D.C., I walked up to the McPherson Square metro station and stopped for a moment to stare. There on the sidewalk, hanging around the entrance, were two ducks. I think they were together. I mean, I’m not a duck expert, but they looked quite different from each other, so I figured it was a guy duck and a girl duck. And I say hanging around because they really were at ease. More than that, even. The vibe coming off them was pretty tough, like they were saying “this is our corner, you got that?” Maybe this seems normal to you — urban duck couples “owning” the turf around public transit — but I’d never seen a duck in the city, other than in a pond, in a park, where they always seemed quite skittish. These ducks had some swagger in their waddle. I followed the pigeons’ lead and kept my distance.