Spring is the time of year when most male birds support their brightest colored plumage. This makes them more attractive to a potential mate for the breeding season, however it also makes them more visible to any human traveling through their domain.
Among the birds far more likely to be seen during spring than at any other time of year is the hooded merganser, a handsome species of waterfowl that commonly resides in the many wooded wetlands scattered across the Park.
The hooded merganser is a bird roughly the same size as a wood duck, and which gets its name from the enlarged shape of the back of its head. This cranial feature is produced by a puffy patch of plumage on the rear of its head, which can be greatly expanded, or contracted, depending on circumstances. In the male, this hood is a distinct white and rimmed with a conspicuous black band making it quite noticeable when an individual is attempting to impress a nearby female with his appearance. The chest of the male is also a striking white color, however, unlike the common merganser which supports white plumage over the length of its sides, the hooded merganser has a characteristic tannish-brown color to that part of its sides visible above the water line.
Unlike the common merganser which prefers to reside in lakes, large ponds, and along stretches of sizeable rivers and marshes, the hooded merganser confines its activities to smaller wetlands, especially those surrounded by trees and shrubs. Beaver ponds, alder-choked streams, marshes that adjoin flooded woodlands, and the backwaters of rivers and narrow and deeply recessed bays of lakes cluttered with fallen trees from shore, all serve as home to this aquatic bird.
Because travel through these settings is often a challenge for a person, the hooded merganser is not as likely to be glimpsed as its larger cousin, which regularly swims in waters likely to be used by kayakers, canoeists, and other boaters. Additionally, the limited visibility in such closed wetlands further reduces the chances of seeing a hooded merganser. During April, after the ice goes out, and for the first few weeks of May, before the leaves emerge from the buds of our deciduous trees and shrubs, it is occasionally possible to a glimpse a pair of hooded merganser, especially when visiting the shore of a quiet beaver pond, or fishing on the banks of an alder laden stream.
The wary nature, or secretive behavior of the hooded merganser also contributes to the difficulty in getting a good view of this unique looking duck. Because it resides in places that are frequented by mink, fox, coyote, bobcat and other shoreline carnivores, this duck has developed the ability to quickly detect and silently move away from any larger creature that it happens to hear or see moving in the general neighborhood.
Like other mergansers, this bird is well adapted for diving under the surface and snagging small fish that exist in bodies of fresh water. The thin, serrated bill of all mergansers enables these predators to firmly hold onto a squirming minnow, or finger-size trout until it can be correctly positioned in its mouth before being swallowed.
The shorter bill of the hooded merganser, compared to that of its relatives, allows it to additionally prey on the abundance of other aquatic organisms that reside in these typically shallow and murky waters. Researchers have noted that the hooded merganser is just as likely to target a salamander, small frog, crayfish, or some large water insect as a small fish. This makes the hooded merganser more of an opportunistic predator, compared to its fish eating relatives.
At this time in spring, the female is in search of a nesting site, which usually is located within the cavity of an old tree close to the shore. Like the wood duck, goldeneye, and common merganser, the hooded merganser strongly prefers to place its nest in some type of enclosure situated above the forest floor. Because of the abundance of large dead trees scattered throughout our wilderness forests, this bird usually has very little problem finding a suitable nesting site. In areas in which foresters have removed many of the larger trees that could eventually produce a cavity sizeable enough for a duck and its clutch of eggs, the hooded merganser is frequently forced to travel well inland away from the water’s edge to find something appropriate. In some areas, it may utilize an artificial nesting chamber, like a wood duck box, put out by a person for housing the nest of a waterfowl.
It is not common to see a hooded merganser, as this wary species of waterfowl confines its activities to places not regularly visited by people, and should a person wander into its territory, it is quick to slip into the background, where it can completely disappear from view. Over the course of the next few weeks, before the leaves fully develop on the trees, it is occasionally possible to glimpse a pair of these birds swimming about the debris jutting above the surface of the water, as the male’s colorful plumage makes it fairly conspicuous. The hooded merganser is a fairly common resident of the Park, and now is the time to best see this bird, for in another few weeks, the chances of seeing one is less than the chances of viewing a bittern during the middle of summer.