November Species Spotlight: Gadwall

Gadwall photo by Adrianna Nelson

One of my favorite times of year is fall, but not because of the promise of holiday foods, cooler weather, or beautiful foliage. I love it because late fall marks the arrival of wintering ducks in our region. The avid birder may already know that ducks spend the cooler months here, but others may be surprised to learn that many species speckle the waterways of Southern Appalachia from late fall to early spring. Truly, ducks are a fascinating and diverse group. I recall an instance in which I found nearly a dozen species on a small farm pond in East Tennessee. A single Common Goldeneye was surrounded by Greater Scaups, Lesser Scaups, and Redheads, all disappearing and resurfacing in the dark water as they dove for food. Towards the banks of the pond, a large group of miniscule Green-winged Teals were busy munching on vegetation. Nearby, a lonely Northern Shoveler kept watch, holding up its awkwardly large bill. Moving about the pond was another species – the Gadwall (Mareca strepera).

The Gadwall, sometimes simply called “gray duck,” is aptly named. From a distance, adult males appear to be mostly gray – a somber getup. Upon closer inspection, however, striking details become evident. Incredibly fine scaling and barring cover the male’s breast and flanks. Creamy brown feathers drape the back, which contrasts with a black rump patch. Given the right angle, a warm chestnut patch on the wings may be seen when the duck is at rest or in flight. Females are similarly sober in color, yet intricate in pattern. They are completely covered in brown mottling. The orange bill and bright white speculum (wing patch) are readily visible. Though not the flashiest of species upon first glance, the Gadwall has a rather subtle charisma.

Though the origin of the name “Gadwall” is not perfectly clear, its scientific name “strepera” means “noisy” in Latin. This bird is well-named – the Gadwall can be quite boisterous. Males in particular make lots of noises, especially when displaying for females. They emit high-pitched, raspy whistles and make a strange quacking sound that is often called a “burp.” The females also make a quack that sounds very similar to Mallard ducks. A large group of Gadwalls can cause quite the cacophony! Where there is a flock, there will surely be territorial or courtship behaviors. Ducks often make interesting movements such as head bobbing, bill opening, and water tossing during courtship displays and aggressive interactions. They have even been known to steal food from other species. These behaviors are fascinating to observe, and can be seen while the Gadwall overwinters in our region.

Gadwalls breed in the Prairie Pothole region of the United States and a few other scattered locations in the tundra and Northeastern US/Southeastern Canada. It is important that they have both wetlands for foraging and vegetated upland habitat for nesting. A female will often make a depression in dense grasses or other vegetation, then line it with her feathers before laying a whopping 7-12 white eggs.

This species overwinters throughout Mexico and most of the Southern US. Here in Southern Appalachia, the Gadwall can be found around the edges of small ponds, lakes, and streams from late October through early April. This duck can be seen with its head completely submerged in the water with its tail held up in the air. This behavior, called “dabbling,” is shared among many other duck species. The Gadwall does this to reach vegetation (ex: grasses, sedges, algae) and invertebrates (ex: beetles, snails) in the shallow portions of water bodies. Other ducks are built for diving underwater to catch their prey, leading to a broad division of ducks known as “dabblers” and “divers.”

Gadwalls and other ducks face many predators. Foxes, coyotes, mustelids, birds of prey, and snakes feast on adults, juveniles, and eggs. Peregrine Falcons will sometimes take Gadwalls even though they are nearly the same size! Humans are also efficient Gadwall predators. After Mallards and Green-winged Teals, Gadwalls are the most hunted species of duck in the US. Luckily, hunting does not seem to be having a negative impact on their populations. Groups and protection plans like the Conservation Reserve Program, Ducks Unlimited, and North American Waterfowl Management Plan work to regulate hunting and ensure that gamefowl have adequate habitat for nesting and migration.

For those who are not familiar with the ducks that winter in the Southern Appalachians, I recommend spending some time around our lakes, ponds, and streams this season. Keep an eye (and ear) out for the wonderfully surprising behaviors of our winter ducks.

Sources:

https://www.allaboutbirds.org/guide/Gadwall/overview

Jobling, James A (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp. 46, 367. ISBN978-1-4081-2501-4.