Ross's Goose in St. Louis County
2012-10-29

Uncommon in St. Louis County in the Fall season

This probable Ross’s Goose (juvenile) had been present at Bayfront Park in Duluth since 9 October, recently associating with one Cackling Goose and two juvenile Greater White-fronted Geese, including on 23 October when this photo was taken (thanks to Don Kienholz for these reports). This may also be the same bird photographed by Kim Eckert at McQuade Road on 7 October. Many of the observers have felt this bird may not be a pure Ross’s Goose, however, with the following characteristics indicating possible passed introgression with Snow Goose: slightly larger overall size than the adjacent Cackling Goose with a very fat body which hung nearly to the ground on the standing bird, noticeably but slightly larger overall bill size compared to the adjacent Cackling Goose, elongate shape to the bill without the typically more stubby and triangular shape of most Ross’s, slightly convex shape to the upper side of the upper mandible, very large and prominent gape (between the upper and lower mandibles), irregular base of the bill (in more typical Ross’s the junction between the bill and the facial feathering is more straight up and down), and consistently sloped forehead shape (Ross’s forehead is generally more rounded and steep). Any additional informed comments on this bird are welcome. Although Ross's Goose is a regular migrant throughout much of the state, increasingly so in the Duluth area, apparent hybrids with Snow Goose have been seldom studied. My thanks to Peder Svingen, Kim Eckert, and Jan and Larry Kraemer for discussions and information concerning this bird.

Karl J. Bardon