One of which was noted to be paler than the others as early as January 24th, but it took 2 more months before it was taken seriously. Thanks to Andrea Dicks (who photographed it in January and I rashly identified it as Wilson's) and Bruce M who got some great shots of it last weekend. If it weren't for their photos I wouldn't have been there today with Alison Mews with hopes of getting the crucial underwing photos.
The bird of interest is in the middle:
Note the slightly more buffy tones to the bird - particularly in the coverts and scapulars
The following 4 photos focus on the scapulars:
Note on the Common Snipe that the dark patch at the distal end of the scapular feathers is smaller in comparison to that of the Wilson's Snipes. Also, the orange areas are more extensive and generally lighter in colour. These are the details that give the bird a more yellow impression overall.
This particular Wilson's Snipe was easy to confuse with the presumed Common Snipe due to the similar orange coloration in the scapulars.
Comparing the above 4 photos it seems that the Common Snipe has significantly less extensive dark barring (in number and width) of the covert feathers. This is another feature to help find a possible Common Snipe.
A similar pattern is seen when comparing the mantle feathers of the two species. The probable Common Snipe is in the back with head facing away.
The next thing to investigate are the tertials. On Wilson's Snipe the dark barring is wider than the light bars, and this dark barring becomes even wider towards the distal tip of the tertials. Whereas in Common Snipe the width of the dark bars and the light bars is more or less equal throughout:
Common Snipe is in the back right
Interesting to note the difference in rump patterning in the above images. Not something I've read about anywhere, so may be worth looking into as an additional ID feature.
The problem with identifying an out of range snipe is the simple fact that snipe have significant intra-species variation. In other words, there is a lot of variation from one Wilson's Snipe to the next. And, similarly, there are differences depending on the age (i.e. 1st winter vs. adult). This variation is poorly understood, even when it comes down to determining the age of any individual. Generally with shorebirds it would be considered a bad idea to try to identify a rarity without being able to age it first, but that can't be relied on when identifying snipe.
Identifying this probable Common Snipe based on the above features alone wouldn't be very convincing. Although the tertials, coverts, and scapulars all add up to a possible Common Snipe, the differences aren't very striking (unlike last winters bird).
That's why I returned to the snipe ditch today with Alison Mews with the single goal of photographing the underwing.
Here is what we got:
Compared to a photo of the Wilson's Snipe:
The underwing of the Wilson's Snipe obviously has more extensive dark barring throughout the underwing. This difference is most striking in the median and greater underwing coverts - as mentioned in the Pyle guide.
The Common Snipe has a mainly white underwing with well separated black bars.
Another Wilson's Snipe, with the longest axillary feather just barely visible confirms that this species has wider and more prominent dark bars:
And, for comparisons sake, here is the underwing of last winters obvious Common Snipe in a nearby location. To me, the barring of the axillaries is equal to that of todays probable Common Snipe:
Before seeing the underwing we had a moderate suspicion that this bird was a Common Snipe. The underwing definitely provides strong support for that identification.
A look at the upper-wing of the Common Snipe:
Upper-wing of the Wilson's Snipe:
The white trailing edge to the secondaries is supposed to be broader and more prominent on Common Snipe. The above photos are a little too blurry to really evaluate if there is any difference. But I could convince myself that there is a broad white trailing edge to the secondaries of the probable Common Snipe.
Based on these photos it seems that there is a strong case that we have a Common Snipe.
But when you look at this photo taken by Bruce M last weekend, you'd be excused if you have difficulty seeing the difference between the two species:
Common Snipe is on the left (best way to confirm this is by checking out the tertials).
Compared to our previous two records of Common Snipe, this bird is much more difficult to distinguish from the regular Wilson's Snipe.
The differences are subtle. Rushing into an identification is out of the question. That's why we have to get clear shots, preferable with Wilson's Snipe for direct comparison, including the difficult to capture underwing photos. Thankfully we were able to attain all those photos. Now it's up to everyone else to decide if they agree.
Feel free to email me (or comment below) if you disagree, agree, or have something else to add to the discussion/identification:
alvanbuckley AT gmail.com
Some resources if you're interested in looking further into this:
And if you really want to be confused, check out these photos of Common Snipe from Japan: