Hooded mergansers are small ducks with yellow eyes and slender bills. Like most ducks, the males are much more colorful than the females of the species.
Males are black on top with a white breast and reddish-brown sides. They have unusually large and odd-shaped heads, which is where the “hooded” part of their name comes from. Their hood, also called a crest, has a large white patch that is surrounded by black. Males can raise or lower their hoods, which can make the size and shape of their heads and the white patches look differently.
Females hooded mergansers are mostly brown. Their crests are a light orangish-brown color. They look ragged at the edges compared to the smooth edges of the males’ crests.
Hooded mergansers are diving ducks. That means they can swim completely underwater. Like many animals, hooded mergansers have a nictitating membrane. Nictitating membranes are clear to clearish eyelids that move sideways from the nose to the outside of the face. They allow animals to see while protecting their eyes from debris and preventing them from drying out.
When a hooded merganser dives for food, its nictitating membrane acts like a pair of built-in goggles. This way they can see their prey. They hunt for small fish, crayfish, a variety of aquatic insects, amphibians, snails and slugs.
Hooded mergansers nest in tree cavities that are usually close to water. The females lay between five and 13 eggs. Sometimes they may lay their eggs in another hooded merganser’s nest. A nest was once found with 44 eggs inside!
Just one day after the eggs hatch, the courageous little ducklings leave the nest by hopping down to the to ground all by themselves. This can be anywhere from a 10-foot to 50-foot drop. They then waddle to the water, where the young mergansers are ready to find their own food. Watch some young ducklings leave their nest and make their way to water.
Because they nest in tree cavities, hooded mergansers will also take advantage of the homes people build for wood ducks. If you live near water, you can build and mount a box and provide the perfect habitat for cavity-nesting ducks, including hooded mergansers. Cornell Lab of Ornithology has a Nest Watch webpage that will give you information on building a hooded merganser nest box and where and how to place it.
Traditionally, the hooded merganser’s habitat has been wooded areas surrounding or close to bodies of water like creeks, lakes and ponds. Their habitat has expanded to open marsh areas because humans have mounted artificial nest boxes on posts.
In the wintertime, you can see hooded mergansers at Four Rivers Environmental Education Center in Channahon. Plan a visit to see these beautiful birds, along with the many others that make our rivers their winter home.
Follow Willy's Wilderness on Facebook for more kid-friendly nature stories and activities.