An American Robin and hoarfrost in the shallows of Heron Pond during the wintertime (photo by Gary Shackelford).
Although American Robins have a well-known reputation as harbingers of spring, populations can be found throughout the northern continental U.S. in winter, including Wisconsin. Their winter numbers vary significantly from year to year. Robins that do not overwinter in the southern U.S. and Mexico change their behavior, reflecting adjustments that are largely adaptations to the availability of food resources. Unlike their behavior during breeding season, robins are not territorial in winter. They travel widely in flocks in search of food, and they do not stay in one location for very long. Their diet changes from mostly animal material to plant matter, especially fruits of an assortment of plants—natives such as dogwood, grape, sumac, poison ivy, Virginia creeper, and red cedar, and nonnatives such as common buckthorn. They do continue to consume some invertebrate animal matter, especially in wet areas where the ground doesn’t freeze.
American Robin with a tiny invertebrate prey item in its bill (photo by Gary Shackelford).
At Fair Meadows Sanctuary, the primary source of water in Heron Pond is underground springs. The temperature of groundwater in our area is approximately 50°F, and the brisk upward flow of water maintains a warm enough temperature that the pond never freezes. Unfrozen water in the shallows creates conditions that provide a reliable source of invertebrates that are fed upon by a variety of winter birds, including robins. An adjacent saturated area that has constant seepage of warm water from the base of a hill provides additional unfrozen wetland habitat where they can feed.
American Robin bathing in shallow water (photo by Gary Shackelford).
I have spent many hours at Heron Pond in winter observing wildlife, including robins that occasionally come in to forage. By positioning myself in a blind, I have been able to photograph them while they feed. The occasional days with heavy hoarfrost on the rocks, mud, and vegetation are extra special. On one memorable day this winter, I walked down toward the pond on a scouting expedition and was treated to the sight of a flock of robins that were mostly feeding or loafing. A few were even bathing. As I observed them, I thought: The water temperature might be good enough for a robin to take a bath, but I think I’ll hold out for something warmer!
Written by Gary Shackelford, Fair Meadows Sanctuary resident manager
Cover image by Gary Shackelford. An American Robin pokes its head above a snowbank.
