On Thurs. am. I returned to check out the NRWS. at Iona and the first few definitely had a square tail. Problem solved? Until right in front of me appeared a NRWS with a notched tail, although admittedly not as deeply notched as a Tree or Violet Green. Back home to check out more field guides and Peterson(2009), Smithsonian(2008) both show NRWS as having a slightly notched tail. Is this possibly an intergrade situation? Also, nowhere have I been able to find a description of PUMA appearing brown although in 2 references it says it can be mistaken for European Starling! Perhaps not every horse is as it first appears.

If things are backlit, shadowed, or the light is flat, it's easy to get the colour wrong, quite apart from the existence of colour variants in the species. I find degree of notching to be unreliable as a primary criterion. So I agree that these features aren't the most diagnostic.

However, the Sibley Field Guide to Birds of Western N. America (2003) says about European starlings "Distinguished from all other birds by shape and habits." The same guide also says that adult purple martin males can be confused with European starlings, which seems contradictory. However, I think the Sibley statement about European starlings is right, and the one about purple martins is wrong. Starling and martin shapes are so different that I can't imagine any circumstance in which they could be confused flying, perching, or walking. Perhaps I lack imagination.

Hugh

I agree completely on the confusion of Starlings and Martins. I can't see how anyone could confuse them. As to the notch in the tail it seems to me that the appearance of a notch can not definitively exclude NRWS as a possibility given that both in the field and in various guides NRWS is shown to have some degree of notching. The Smithsonian Field Guide to the Birds of North America on p.327 has a picture of a NRWS that looks somewhat like the picture in question. Although Katherine's picture is much darker they both show a notch in the tail. While I agree we cannot rely on only one feature, if that is the only clear feature it shouldn't be excluded for consideration either. As for imagination I'm sure yours is as rich as mine which makes for great discussion.

I can imagine easily a situation in which I would confuse purple martins and northern rough-winged swallows. I was predisposed to see martins at nestboxes over water having seen them the week previously at Maplewood flats and Iona in similar habitat. It occurred to me that the colour didn't seem right, but I excluded rough winged swallows because I didn't see any sign of a lighter breast, otherwise plainly visible on other swallows on the same post. What I should have wondered is why I didn't see any purple martin females....

Hugh