Species of the Month: Redhead
In Norfolk County, and much of the Carolinian Life Zone, winter is the best time for waterfowl birding. A large diversity of ducks can be regularly observed in Lake Erie around the coast of Long Point and Turkey Point. In the winter months, these include often copious amounts of Redheads, Canvasbacks, and Scaups. Other diving ducks may be present in lesser numbers, such as long-tailed ducks, mergansers, buffleheads, goldeneyes, ring-necked ducks and possibly a few rarities, such as scoters. Dabblers can include pintails, shovelers, gadwalls, wigeons, wood ducks, American black ducks, and (of course), mallards. Canada geese, and Ontario’s 3 species of swans, the trumpeter swan, tundra and introduced mute swan, are often present to accompany the duck species.
Redheads are one of the most common species of wintering waterfowl in the Long Point Bay area. Redheads are medium-sized ducks (slightly smaller than a mallard, and larger than scaups), with males measuring ~42 cm in length. Females are slightly smaller. The wingspan of Redheads is ~78 cm. Male Redheads have a characteristic red head, which slopes sharply towards the bill (at an 120 degree angle) with a black chest, bright yellow eyes, and a mostly gray body. The bill is broad and gray, with a black tip. The only ducks that are similar in color pattern are male Canvasbacks. However, male Canvasbacks have a white back (similar in colour to a canvas), and a red eye, and a forehead that slopes at a gentle angle towards the bill (170 degree angle). Female Redheads are light brown, with a small white eyering, and a darker bill than males.
Redheads attain most of their energy requirements by feeding on plant matter (such as seeds and tubers), as well as from aquatic invertebrates. Though classified as a diving duck, redheads will sometimes display dabbling behavior, similarly to true dabbling ducks such as Mallard. With plenty of herbaceous wetlands, where most of the preferred food sources are found in large quantities, Long Point is ideal habitat for Redheads.
To create a better understanding on why Redhead ducks occur in such copious numbers at Long Point, its biology and annual migration cycle must be considered. The highest proportion of the Redhead population (>50%) breeds the Prairie Pothole region – a natural region west of Lake Superior stretching from southwestern Minnesota through the eastern Dakotas to southwestern Manitoba. The Prairie Pothole region is a mosaic of emergent herbaceous wetlands, tallgrass prairie and cropland. Other breeding areas include the herbaceous marshes throughout the Great Lakes region. Female Redheads lay 5-8 eggs per clutch, averaging 1 egg per day. The incubation period in total is around 25 days. Though Redheads will create their own nests, Redheads are also known for brood parasitism, laying eggs in nests created by other females, and as well as nests created by other species (including, oddly enough, the American Bittern). Parasitism occurs more often in years where food supplies are ample. As in most other duck species, the female will raise the offspring alone, with males migrating to lakes in Canada’s boreal forest region to complete their molt in August. During the molt, males will appear similar to females, a muted brown.
In autumn, Redhead ducks will begin to migrate southeast, where populations will gradually make their way into the Great Lakes region. They will arrive at their wintering areas by December. When observed in the Great Lakes, they are most often seen in large flocks, called “rafts”. These rafts occur throughout the Great Lakes region, such as the Straits of Michilimackinac (between Lake Michigan and Lake Huron), where populations peak at 25 000 individuals. In the Long Point Bay area, peak population numbers are usually above 10 000 individuals.
For the duration of winter, Long Point Bay is an optimal location for Redheads (and the similar Canvasback). On some days, birders will be fascinated by the massive number of ducks that can be found in such a small area. A helpful tip for birding photographers – try to select days where it isn’t too cold, as lows of -10 Celsius or colder on winter mornings can make photography very difficult, especially when manually adjusting the camera for aperture, shutter speed and light sensitivity. Warmer winter days with temperatures around the freezing point (0 Celsius) are optimal for waterfowl photography.
Written By:
Matthew Palarchio, Honour’s BSc in Environmental Science candidate, Western University
