ABSTRACT
Lesser snow geese, greater snow geese, and Ross’ geese are large conspicuous birds which breed in colonies in treeless arctic regions, mainly in Canada. Photograph the nesting geese in June, approximately half way through their incubation period. Visually analyze original negatives in roll form on a light table with a binocular microscope. Photographic census or estimation of the colonies of lesser snow geese of the western Arctic and of greater snow geese are easier since they do not contain significant numbers of blue phase birds. The colonies of Ross’ geese and lesser snow geese in the central Arctic present special problems since they contain variable proportions of each species and only the lesser snow contains the blue phase. The blue phase can be separated from the white snows and the Ross’ geese, but the latter two cannot be separated on the aerial photos.
