If you’ve visited Goose Pond Sanctuary or checked our live webcam in the last three weeks, you may have noticed something different about the pond. There’s water in it! By March 1, the pond was ice free, and has been filled with migrating waterfowl. In the midst of thousands of honking Canada Geese and two thousand whistling Tundra Swans, you may spot a flash of the deep, bright red head of a male Redhead duck. Unlike Canvasbacks that also sport a red head, Redheads have rounder heads, a bluish gray bill, and a more compact-looking body than the slightly larger Canvasbacks.
Redheads flocked with other ducks, including Bufflehead and Common Goldeneye (photo by Arlene Koziol).
These gregarious ducks spend their winters in large mixed flocks on the Gulf Coast and sometimes in the Great Lakes. Redheads are social and can be found huddled with Buffleheads, American Coots, Common Goldeneyes, and other waterfowl in groups up to 60,000 using large water bodies on their wintering grounds. During spring migration, Redheads seek refuge on medium-sized water bodies before making their way to the marshy freshwater lakes and ponds of their primary breeding grounds in central Canada and the Western Great Plains. Although there are no documented cases of breeding Redheads at Goose Pond Sanctuary, the west pond and newly constructed wetland scrapes provide critical habitat for migrating Redheads and other waterfowl.
Last week, Emma saw nine Redheads resting and foraging on the wetland scrape, while eBirders recorded 100 Redheads at Goose Pond on March 11 and 16. Mark and Jerry Martin counted waterfowl on March 21 that included 54 Redheads (23 on the east and west sides of Goose Pond and 31 on the created wetland on the Jackson Wildlife Unit); see their eBird report for more information. Flocks of Redheads and other diving ducks in spring migration usually contain more males than females. Mark and Jerry’s count on March 21 had a flock of 31 Redheads with 25 drakes and six hens. The unbalanced sex ratio may be contributed to the predation of nesting hens. The Goose Pond high count reported by Jeremy Cohen and his party was 400 on March 31, 2019. The Columbia County high count was 420 on March 24, 2020 at Harvey-Wangsness Wetland reported by Ted Keyel. The local area, including Goose Pond, had record high water levels in 2019 and 2020, which may explain the abundance of Redheads.
Redhead males outnumber females at Goose Pond Sanctuary while migrating, March 2023 (photo by Al Roske).
Although migration periods are the best times to reliably see Redheads on Wisconsin water bodies, there is one place in particular that Redhead fans can watch breeding pairs throughout the summer: Horicon Marsh. Before Canada Geese filled the 33,000 acre marsh, the Horicon National Wildlife Refuge was established to provide nesting habitat for waterfowl, namely Redhead ducks in 1941. Since then, Horicon Marsh remains one of the top nesting sites for Redheads east of the Mississippi River, supporting 2,000-3,000 nesting individuals a year.
Once female Redheads arrive at their nesting sites, they have four options:
lay a clutch of eggs in their own nest
lay eggs in other birds’ nests (brood parasitism)
lay eggs in other birds’ nests and their own nest (semi brood parasitism)
lay no eggs at all
Water levels and food availability determine the nesting strategy of female Redheads each year. If water levels are low, there could be a lack of food and a higher risk of predation, which may influence Redhead hens to fully parasitize other Redhead nests or the nests of other ducks such as Canvasbacks, Mallards, Northern Pintails, Gadwalls, Northern Shovelers, Ruddy Ducks, and American Wigeons. Redheads have also been reported to parasitize the nests of Soras, Ring-necked Pheasants, and even Northern Harriers! Redhead hens may also opt to maximize their reproductive success by acting as a semi-parasite. In that case, hens may lay a few eggs in other individuals’ nests, but will also lay their own clutch of eggs to incubate.
While habitat conditions play a significant role in deciding which reproductive strategy the hens will adopt, their decision is also dependent on the hens’ fitness. If nesting conditions are poor and the hen is young and skinny, they may choose to not lay eggs at all that year. Although brood parasitism is common in other species of ducks, Redheads are set apart due to the complexity of their nesting decisions.
Redhead nests (courtesy of Wisconsin Breeding Bird Atlas II).
According to Breeding Bird Atlas records, Redheads were confirmed nesting in 10 atlas blocks in Atlas 1 (1995-2000) and 16 blocks in Atlas II (2015-2019). Three of the Atlas 1 and four of the Atlas II blocks were at Horicon Marsh. Another good area to find nesting Redheads is Rush Lake and the adjacent Uihlein Waterfowl Production Area (WPA) in Winnebago County where three blocks had nesting confirmed. Most of the remaining blocks in Atlas II where Redheads were confirmed were on large state wildlife areas, mostly in southeast Wisconsin, including Collins Marsh, Hope Marsh part of Grand River, Mack, Mullet Creek, Powell Marsh, and Wolf River Bottoms. As expected, the majority of the confirmed nestings were observations of broods.
Broods were also reported at Schoeneberg Marsh WPA adjacent to Madison Audubon’s Erstad Prairie about three miles northeast of Goose Pond Sanctuary. In many years, Goose Pond has pairs in the summertime and was listed in the atlas reports as “probably nesting.” In coming years, we hope the Redhead will join the eight other species of ducks that are confirmed to nest at Goose Pond.
Written by Emma Raasch, Goose Pond Sanctuary ecological restoration technician, and Mark Martin, Goose Pond Sanctuary resident co-manager
Cover image by Martin Knippel/Audubon Photography Awards. A male Redhead, with a yellow eye, blue-gray bill, auburn head, dark neck and chest, and gray wings and back takes off from the water.
