Yet all were left unstoned

This is a colony of white-fronted terns (Sterna striata) on the end of the Aramoana mole.

Pair-bonds are retained from one season to the next.* Before laying, the male courtship-feeds the female, presenting small fish to her. Predators or humans entering a colony are repeatedly dived at. 

"Are they here all year round?" the Frau Doktorin wondered.
"Of course they are!" I said, confidently though incorrectly. "In every season, tern, tern, tern."