I really thought that I was just imagining things. But YES! My Saxony duck, Cinnamon whistles at me. It's not a sexy whistle, but more of a beaconing whistle. As if to say, "Come back, don't go!" He did it once. He did it twice... thrice! And now he's doing it all the time. Every time I go to leave Cinnamon calls after me with a distinct whistle! I had no idea!