https://groups.google.com/d/msg/maine-birds/brvJPdhYgVA/ngo6qI2vZvAJ
One potential problem I mentioned then is the misperception that rusty staining is indicative of subspecies. It may not be. Some field guides illustrate both the rusty-stained spring birds and the gray fall/winter birds but show only one of the seasonal plumages for each subspecies. The Sibley guide, for example, shows the rusty spring appearance for Lesser but only the gray fall for Greater. Although labeled clearly and a fall (gray) Lesser is illustrated, I can see the potential for confusion where folks think the rusty ones are more likely to be Lesser Sandhills.
A key character to look for is the color of the primary shafts. This has not been studied in depth and is not widely known (and may not prove diagnostic). A photo of the spread wing photo would help. Greater Sandhill Crane is said to have the primary shafts entirely ivory white, whereas Lesser has at least the distal third of the primary shafts dark.
The bird in Derek's photos does look comparatively short-billed and short-legged suggesting Lesser Sandhill, but a problem with cranes is that the sexes can differ dramatically in size, females being smaller. I have photos showing family groups where the female looks tiny compared with her mate and her son (fall photo so age apparent).
It certainly is worth keeping our eyes out for these smaller, northern breeders.
Louis Bevier
Fairfield
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