Lisa Duke stands by a lake at the Kellogg Bird Sanctuary near Augusta. A variety of birds stand near the shore: mallard ducks, Canada geese and, much taller than everyone else, trumpeter swans. With mating season on the way, Duke says they’ve got moves to practice.
"The newer pairs, they do this head bob in unison. So they keep practicing their head bobs and calls together and it kind of reinforces that pair bond," she says while swans trumpet nearby.