Within 24 hours of hatching, Hooded Merganser ducklings leap anywhere from 8 -90 feet from their arboreal cavity nest down to their mother, who is calling to them from the water below. Capable of swimming and diving right away, the ducklings begin feeding themselves immediately. Weighing little more than an ounce, they mostly eat insects, including backswimmers, water boatmen and diving beetles. Eventually, as the ducklings grow, they work their way up to fish and crustaceans — particularly crayfish, such as the pictured merganser has caught. In addition to its size, the lack of a real “hood” indicates that this Hooded Merganser is a youngster.
Backswimmers are aquatic insects that seek out prey as large as tadpoles and small fish. They row around ponds with their fringed hind legs and grasp prey with their front pair of legs. The piercing mouthparts that they use to kill their prey are also capable of giving humans who handle them carelessly a nasty bite (they are also known as “water wasps” for this reason). Because they spend most of their time on their back, their coloring is opposite that of most insects – backswimmers typically have a dark belly and a light-colored back, making them less conspicuous to predators (and prey) both above and beneath them. These tiny bugs can stay submerged for hours thanks to their ability to store air bubbles in two channels on their abdomen which are covered with inward-facing hairs. Backswimmers are often confused with Water Boatmen, which are not predaceous, do not bite, and swim “right side up.” Water Boatmen’s dark color and parallel lines on their backs help distinguish them from Backswimmers.