Because it was announced to the list serve on Sunday that I was the one to identify the small white goose at Ashtabula as a Ross' Goose, I decided to respond to this thread.  The small white goose that I ID'd as Ross's Goose had a relatively small conical bill, with a straight vertical posterior edge (toward the eye) and bluish gray base of the bill and a steep forehead and rounded crown and head shape.  There was some grin patch, but it did not include the large bulge in the grin patch as in Snow Goose nor was the amount of grin extensive.   I know that discussions have made the point that Ross's have no grin mark, but I have read discussions that indicate Ross's often do have some grin line.  That's also been my experience studying the large flocks of Ross's Geese in California in the fall/winter.  To ID the bird I concentrated on the head shape and bill shape.  I studied the bird though a telescope at perhaps 50 yards, perhaps more.  Jerry Talkington showed me a close-up photo that he took on Sunday while I was at Lake Shore Park.  His close up photo taken at a perpendicular angle to the bird showed a steeply rising forehead and the bill shape that I describe above in this message.

For whatever it is worth, when I arrived on the scene, I was told the small white goose was a Snow Goose.  The bird I ID'd did not have a Snow Goose bill, and definitely did not have the concave curvature in the feathers at the posterior edge toward the eye.  The bill and head shape was wrong for Snow Goose and did not show a sloping profile as in Snow Goose.  I'm not sure what to make of Matt's photos.  The head and bill shape on the bird in those photos is not what I recall in Jerry T's close-up photos.  Perhaps it is the angle or what the bird was doing when Matt's photos were snapped?


Bill Whan asked, "Any thoughts from others?"

I'm dubious of the emphasis on size, and particularly using average length measurements, which are frequently if not always taken with the bird laid out as if or really dead from the end of the bill to the tip of the tail.  That requires a good imagination to visualize a live small white goose laid out next to a live Mallard laid out for a size comparison.   In addition, a Mallard and a Ross's or Snow Goose do not have the same shape and body bulk and appear to have different neck lengths.  Therefore, in real life not laid out for length measurement, the length measurement quoted in field guides and references has limited use in my opinion.

In addition, an average length measurement as a means of comparison needs to also include the variability in that average measurement.  An apparent difference in average length indicated by two average lengths, for Mallard and Ross's Goose, for example, may not be meaningful when the variation in both numbers is taken into consideration.  When the variation in the average lengths is included, the results may indicate significant overlap in the average values such that a real difference cannot be detected in the field with live birds not laid out for exact measurement.  (I couldn't resist making this point.  I am a trained, advanced degreed Analytical Chemist, aka measurement scientist, and work with experimental results and variability in the data in my full time job.  Sorry if this steps on a few toes!)

I'm glad Vic Fazio chimed in on this discussion thread!
Jay

Jay G. Lehman
Cincinnati, OH
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