A Hooded Merganser in Hendrie Valley Sanctuary
Bob and I drove out to Hamilton, Ontario, on a recent spring day, and opted to hike a trail system near the Royal Botanical Gardens rather than revisit Cootes Paradise, one of our favorite places to go birdwatching. The Hendrie Valley Sanctuary encompasses a variety of habitats including marshlands, forested slopes, floodplain wetlands and four creeks. It was there, as we walked along a section of Grindstone Creek, that we came upon this Hooded Merganser (Lophodytes cucullatus) paddling its way upstream.
The creek lacked the vigorous current and deep water seen directly after recent torrential rains, so the Merganser had an easy time of it. Hooded Mergansers are short-distance migrants with those from eastern Canada generally wintering in the Gulf States of America, but certain populations will remain in southern Ontario all winter long if temperatures allow for ice-free ponds, rivers and lakes. In fact, Bob and I sighted some Hooded Mergansers this past winter in Toronto Harbour and environs.
Bob and I skulked along the vegetation that edges the creek so as to not spook the Merganser. Hooded Mergansers are frequently seen on small ponds and rivers where they dive for clams, crayfish and frogs. It is because Mergansers have extremely muscular gizzards that they are able to grind up the exoskeletons of shellfish. This small diving duck busied itself by diving for fish that it was able to grip handily with its thin, serrated bill.
Hooded Mergansers prefer to dive in clear, shallow water because they locate their prey underwater by sight. Two adaptations make this possible. One, they are able to alter the refractive properties of their eyes to enhance underwater vision, and two, they have a third eyelid that descends to protect the eye when swimming, sort of like a pair of swim goggles. This third eyelid is transparent and is called a nictitating membrane.
It was wonderful walking along the edge of Grindstone Creek, relishing the warm sunshine and soaking up the sounds of nature. A pair of Belted Kingfishers kept patrolling up and down the shoreline, treating us to their loud rattling calls. Intermittently, they perched just out of camera range then would fly away using their long wings to gracefully glide upwards. Grindstone Creek is an essential part of the Grindstone Estuary located at its mouth in Lake Ontario. Herring and Spottail Shiners both do spawning runs up the Creek in the spring, so the Creek is an ideal spot for both the Kingfishers and the Mergansers to fish.
The Hooded Merganser dabbled in the rippled water all the while showing off to great advantage the jet black plumage on its head and back. From this perspective, the white hood for which the duck is named appears as two white bands extending back from behind the eyes. When the crest is down, the white bands almost converge at the nape of the neck. Also of note are the fine blackish lines, called vermiculations, on the chestnut flanks.
Although this Merganser was quite aware of Bob’s and my attention, it finally felt relaxed enough to clamber up onto a partially submerged log, there to begin preening. Hooded Mergansers are the smallest of the three Merganser species found in North America, and yet this one is a good-sized duck. Most species of Mergansers sport red bills whereas the bill of a male Hooded Merganser, a drake, is black. The bills of all Mergansers are specialized being slender, elongated and serrated, and they are tipped with a hooked nail. These features are what give Mergansers their alternate name, saw-bills or fish-ducks.
As this Merganser had proven already, Hooded Mergansers are extremely agile when swimming and diving, but because their legs are set closer to the rear of the body rather than towards the front, they are quite clumsy when moving on land. Nevertheless, for an extended period of time, this Merganser proved to be quite the contortionist as it preened its feathers while keeping a keen eye on its surroundings.
As Bob and I took in the entertaining antics of the Merganser, we noticed that it was becoming a little agitated. When a drake is on high alert, his crest is fully raised revealing the elaborate hood.
It wasn’t long before we spotted a fisherman in hip waders sloshing his way downstream while intermittently casting his line. We learned later on, when a sign was seen affixed to a tree, that fishing in the Hendrie Valley Sanctuary is prohibited given that it is a protected area of significant importance.
Hooded Merganser drakes in breeding plumage are a sight to behold with their white breasts seeming all the more snowy because of the contrasting black “spurs” that reach down the sides. Also part of the breeding plumage are the reddish-brown flanks. Adult males display this striking plumage both in breeding season and during the winter.
A male Hooded Merganser has bright yellow eyes that stand out on its black head, a head that looks too big for its body because of its fan-shaped, collapsible crest. The large triangle of white on the crest is always prominent whether the crest is raised or lowered and perhaps that is why it is so effective in attracting a mate. When courting, drakes expand the white, sail-like crests to gain attention from the hens in combination with low, rolling frog-like croaks.
When male Hooded Mergansers are not breeding, their plumage is like that of the females, dusky brown with crests that are reddish-brown. At that time of the year, it is possible to distinguish the drakes from the hens by the colour of the bills and the eyes. Females have a yellowish bill with some orange at the base, and their eyes are dark brown.
Hooded Mergansers are the only merganser species whose range is restricted to North America. When breeding, the eastern population of these ducks is at its highest concentration in the area of the Great Lakes. It is in early winter that a drake and hen form a pair, but the drake leaves the female to incubate the eggs soon after they are laid. Like Wood Ducks, Hooded Mergansers are cavity nesters that prefer a forested wetland habitat, and there, they seek out suitable cavities in either live or dead trees that are close to water. If previously-excavated woodpecker cavities are unavailable, these ducks are also open to using nest boxes, even those intended for use by Wood Ducks.
As we did not see the female Hooded Merganser anywhere in sight, we would like to think that she was somewhere nearby tending the nest. A female lays between 10-12 white eggs and incubates them for about 30 days. What a sight it would be to see newly-hatched ducklings when they plunge from the nest cavity to the forest floor. That occurs when they are only one day old, as soon as the fluff balls are dry and strong enough to scramble up to the entrance of the cavity and flutter to the ground. The hen will lead her nestlings overland to the safety of the nearest body of water where they are already able to feed themselves and make shallow dives. Now that is precocious!