The relationship between beavers and waterfowl is a strong one. In creating ponds and wetlands, beavers provide valuable waterfowl habitat. Beaver ponds are attractive to most dabbling duck species, particularly American Black Ducks and Mallards (pictured). Dead snags that are often found in beaver ponds provide Hooded Mergansers, Common Goldeneyes, Buffleheads and Wood Ducks with nesting cavities. During spring and fall, beaver ponds are used by migrating waterfowl, such as Green-winged Teal and Ring-necked Ducks, for the fuel they provide (aquatic invertebrates, plant seeds, tubers, buds and rhizomes). Waterfowl surveys in 2002 in Wyoming found that rivers and ponds with beavers had 75 times more ducks than those without beavers.
Yesterday’s mystery duckling was a Hooded Merganser. Wood Duck and Hooded Merganser ducklings are very similar, however Wood Duck young possess a dark, horizontal line behind their eyes which Hooded Merganser ducklings lack. There are several ducks that nest in tree cavities in New England, including Wood Ducks, Common Goldeneyes, Common Mergansers and Hooded Mergansers. Hooded Merganser ducklings leave their nest cavity within 24 hours of hatching, in response to their mother’s calls below. They jump/climb up the wall of the cavity and hurl themselves out of the tree. Depending on where the tree is located, they fall either onto the ground, where they bounce like a tennis ball upon landing, or straight into the water. Hooded Merganser fledglings have been known to fall as far as 50 feet to the ground and then walk as far as half a mile with their mother to the nearest body of water.
It’s been my life’s dream to witness the fledging of young wood ducks from their tree cavity nest in response to their mother’s calls below – perhaps this will be the year! Adult wood ducks have recently returned to northern New England, having already formed mating pairs. They now proceed to perform a number of courtship displays which enable them to maintain this pair bond. The most common display involves the male’s turning the back of his head towards the female as he swims in front of her while holding his wings and tail high. Chin-lifting, feather-shaking, wing-preening, neck-stretching and bill-jerking are just some of the displays that occur during wood duck courtship.
Common Mergansers are primarily fish-eating ducks. Young mergansers require over half a pound of food per day during their first summer, and often supplement their fish diet with insects, mollusks, crustaceans, worms, frogs, small mammals, birds and plants. The pictured immature Common Merganser had just downed a crayfish when it spotted a frog which it succeeded in catching and eventually swallowing.