Jan. 27, 2024: The Common Goldeneye, a medium-sized diving duck, is seen in ponds and waterways around Falmouth in winter months. Males have a black head with a white facial patch and bright yellow eyes. The body is mostly white, with black markings on the back and sides. This Goldeneye was recently seen diving for food along the shore of Oyster Pond.

The Common Goldeneye (Bucephala clangula) is a medium-sized diving duck with distinctive field marks, especially during the winter. Here are some winter field marks for Common Goldeneye ducks on Cape Cod:

1. Head Coloration: The males (drakes) have a striking black head with a circular white patch on the cheek. This white patch extends from the eye to the back of the head, creating a distinctive contrast.

2. Eye Color: Both males and females have bright yellow eyes, which stand out against the dark plumage of the head.

3. Body Plumage: The body of the Common Goldeneye is mostly white, with black markings on the back and sides. Males have a white crescent-shaped patch on the face in front of the eye.

4. Bill: Both males and females have a dark bill. The shape of the bill is relatively short and stubby, with a noticeable black and yellow coloration.

5. **Size and Shape:** Common Goldeneyes have a compact and streamlined body, with a relatively short neck. They are smaller than other sea ducks and have a distinctive shape in flight, with rapid wingbeats.

6. Males vs. Females: The males are more striking with their black-and-white contrast, while females have a more mottled appearance, with brownish-gray tones. Females also lack the white circular patch on the cheek.

Keep in mind that these field marks may vary slightly, and observing these ducks in their natural habitat will provide the best opportunity to appreciate their unique characteristics.