Figure 1. Left: Graylag Goose. Photograph by Valerie Burdette. Right: Swan Goose. Photograph by Brian Zylich.

Graylag Goose (Anser anser) and Swan Goose (A. cygnoides) have a long history of domestication and hybridization with each other. The extensive hybridization of these two domestic geese often makes it impossible to determine for certain if a given individual is truly pure. However, visual field marks can help one to determine an individual’s identity to a degree that is frequently accurate enough for most applications if not perfectly accurate in some cases. I will discuss some helpful features for identifying these species and their hybrids, as well as their hybrids with Canada Goose (Branta canadensis). Everything discussed below refers to the domestic forms of Graylag and Swan geese rather than their wild-type counterparts.

Although many domestic geese are totally white, it is important to be familiar with the basic plumage characteristics of both species. Graylags will often be grayish brown with a mostly monotone neck that is usually darker than much of the body. The neck feathers typically have more ruffles than Swan Geese. The ruffles appear more textured and look like lines in the neck feathers. Swan Geese have more of a two-toned neck, with a richer brown mane running along the entire back of the head and neck. The front of their necks is much paler in typical plumage. Swan Geese also tend to have smoother necks than Graylags, without ruffles.