ML646519815

観察結果の詳細

Continuing at this location from last evening. Although there is a slight curve to the upper two-thirds of the bill where it meets the face (as shown best in the cropped last photograph below), the size and triangular-shape of the bill, lack of a noticeable dark grin patch, overall size of this bird in relation to nearby Canada Geese (as shown in the first photograph below) and the size and shape of the head suggest that this bird is properly recorded as a Ross’s Goose and not a ROGO x SNGO (hybrid), although the possibility of some introgression with Snow Goose cannot be eliminated. In this regard, this goose appears to be closest to the bill and head shape portrayed by Sibley in the third example under Ross’s Goose in the first diagram at the following link: https://www.sibleyguides.com/2011/12/identification-of-white-geese/, and similar to the following Ross’s Goose included in the account of this species in Birds of the World Online at the following link: https://ebird.org/checklist/S21389580 .