By seven the birdbath had already drawn a polite line. Sparrows waited on the rim with their feathers tucked, watching a pale ring of water settle like a collar that had not yet chosen an owner.
We asked at the kiosk across the path. "I thought they were arguing," said a woman with a paper bag of seed. "Then I saw them measuring. The wide circles go to the ones with the widest hops. Nobody cuts."
The park keeper posted a small note on the pebble: please nod before you splash, and only once, so the next bird can find a ripple still warm from the last. By evening the water looked well tried-on and hardly ruffled.