Common Merganser. Photo by Jay “Mac” Davis
One of the first ducks to arrive in the spring and the last to depart before ponds freeze, the Common Merganser, is our largest diving duck. The males have distinct, dark green heads which can appear black depending on light. Their scarlet-orange beaks are long, narrow and serrated. This helps them catch and hold their slippery prey – small fish. They have a white breast and underparts and are dark gray to black on the tail and back. Females are similar in size but look very different. They have shaggy, rusty plumage sweeping back on their head. They have a distinct white chin and neck and are generally gray overall.
Common Mergansers prefer deep, clear ponds surrounded by mature woods. They need older forests where they find holes and hollows in trees big enough to build their nests. They are awkward on land and designed for swimming. So, once the young mergansers leave the nest, they move quickly to water and can be seen following their mother in a tight bunch, even clambering onto her back when still small.
The habitat Common Mergansers use to raise their young is the same as the Hooded Merganser and Common Goldeneye, two other diving ducks that use tree cavities for their nests. Mac Davis, who took the photo of these 11 males on Songo Pond this Fall, reports seeing clusters of young mergansers up on the West Branch mixed with the young of Common Goldeneyes. Do the mothers share daycare duties? Well, maybe in a roundabout way. Both the merganser and goldeneye will parasitize each other’s nests. This means they will lay their eggs in any unguarded nest. This may account for observations like Mac’s which are fairly common.
In the winter, Common Mergansers move south or to larger bodies of water that stay ice free. For Maine birds, this means they don’t have far to go and can be found along coastal bays. They are a social species which means they may be found in large numbers and may mix with their cousin the Red-breasted Merganser which is a more costal species. In the waning days before our rivers or larger ponds freeze over, watch for Common Mergansers before they leave for the coast.
James Reddoch, of Albany Township and Boston, leads birding events for the Mahoosuc Land Trust. Visit Mahoosuc Land Trust at 162 North Road, Bethel, ME. To learn more visit www.mahoosuc.org. To contact James, send your emails to info@mahoosuc.org.
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