On the way to hike South Turner Mountain in Baxter State Park, which supplies the best view of the Katahdin massif for the least effort, I stopped at Sandy Stream Pond. I saw no moose. Instead, sleek cedar waxwings flew out over the pond to catch dragonflies on the wing. Or try to. Cedar waxwings favor fruit, but switching from berry-plucking frugivore to a flycatcher-type insectivore exhibits an ability to adapt when protein is abundant. No surprise, perhaps, since the birds nest in late summer and the extra calories are welcome. If one embraces evolutionary theory, those who have access to more or better food will be more likely to successfully raise young and pass their genes and associated behavior down the generations. The hitch, though, is whether burning the extra calories trying to catch an elusive dragonfly results in a caloric payoff.

I was pondering whether the insect-catching behavior might be evolutionary when a female common merganser — a punked-out spiky redhead of a fish-diving duck that frequents ponds in summer — started flailing across the water, with an occasional very quick dive in between more flailing. I thought she was wounded or protective of young until she came up with a seven-inch trout. Three gulps, followed by three croaks and it was down. She was stirring up the fish. She waggled her tail feathers and swam away, the effort well worth the reward. 

Christine Parrish, a former field biologist technician, recommends mainemasternaturalist.org