There have been a few reports of Ross's Geese in southern Ontario this spring but birders should take note that a small white goose may not be a true Ross's but a Lesser Snow Goose x Ross's hybrid. Seeing such hybrids in Ontario is not a rarity and may actually represent a significant percentage of the Ross's Geese being reported each spring and fall. Careful examination of a number of birds in Eastern Ontario in the past few years thought to be Ross's Geese revealed that almost half were hybrids.
An examination of a photo of the goose at Aylmer by several experienced birders confirm that this bird is such a hybrid and not a pure Ross's Goose. Typically, the hybrids are a bit larger than a true Ross's Goose and look like a miniature Lesser Snow Goose. The bill is a little longer and the head profile is more sloped than the abrupt vertical forehead of a Ross's Goose which has more of a rounded head appearance. It is not a true Snow Goose because it lacks a grin patch and is too small. In the case of this bird, the curvature of the feather line at the base of the bill is slightly convex rather than more vertical in Ross's and there is a bluish tinge at the base of the bill which the Lesser Snow Goose does not have. All of these features are worth checking when you see a small white goose. Size alone will not confirm their true identity, especially if you do not have a Ross's Goose side by side for comparison. If you see a small white goose in flight only, your chances of properly identifying it are virtually nil. Re the spring migration of Greater Snow Geese in Eastern Ontario, it is late with only a small number passing through so far but we can expect the main movement to begin at any time. With over 100,000 birds passing through the region there will definitely be a few small white geese present. Some will be Ross's and some will be hybrids. Brian Morin _______________________________________________ ONTBIRDS is presented by the Ontario Field Ornithologists - the provincial birding organization. Send bird reports to [email protected] For information about ONTBIRDS including how to unsubscribe visit http://www.ofo.ca/site/page/view/information.ontbirdssetup Posting guidelines can be found at http://www.ofo.ca/site/page/view/information.ontbirdsguide
