Common Loons: South Carolina’s Winter Guests
Common Loons (Gavia immer) are found in South Carolina, but not as year-round residents. They visit as migratory winter guests, seeking refuge from freezing northern waters. These aquatic birds typically arrive in South Carolina from late October or November and remain through March or April before migrating back north. Their distinctive calls, characteristic of northern lakes in summer, are less frequently heard in South Carolina.
During their stay, Common Loons display a more subdued appearance compared to their striking breeding plumage. Their backs transition to a duller gray. Their bill also changes from black to a lighter gray or gray-blue. This winter plumage, along with a white throat and underparts, helps them blend into their winter environment.
Prime Locations and Identification Tips
To observe Common Loons in South Carolina, know their preferred habitats and identification features. These birds favor large bodies of water, including expansive freshwater lakes and reservoirs, as well as coastal estuaries, sounds, and tidal rivers. Specific locations like Lake Jocassee in the upstate and Lake Murray in the central part of the state are known overwintering sites, with Lake Jocassee sometimes hosting hundreds of loons. Coastal areas, particularly around the Sea Islands, also offer opportunities for sightings.
Identifying a Common Loon involves looking for its distinct profile: a low-slung body, often riding quite low in the water, a long neck, and a dagger-like bill. They are powerful divers, propelling themselves with their large webbed feet, and can remain submerged for extended periods while hunting fish. When taking flight, loons require a considerable “runway,” flapping their wings and running across the water’s surface for at least 30 yards to gain speed. While their iconic yodel is rare in winter, loons may still communicate with quieter calls.
Understanding Loon Behavior and Habitat
During their winter residency in South Carolina, Common Loons focus on foraging and conserving energy. They are visual hunters, relying on clear water to spot their prey, which consists mostly of fish, crustaceans, snails, and aquatic insects. Unlike most birds, loons possess dense bones, which helps them achieve deep and efficient dives for hunting. They expel air from their lungs and flatten their feathers to reduce buoyancy, allowing for rapid submergence.
While loons are known for their solitary nature on breeding grounds, some social behavior has been observed among wintering populations in South Carolina, particularly in large reservoirs. For instance, on Lake Jocassee, loons spend a significant portion of their day, around 52%, foraging. They may forage individually or, at times, form small groups, with some studies showing that solitary loons undertake longer dives compared to those in groups. These groups can sometimes involve other species like Horned Grebes and Ring-billed Gulls. Loons often sleep in the middle of large, open water bodies to avoid predators.