This page attempts to demonstrate that caution is sometimes needed when assessing photos of skuas/jaegers... :-
Below is the Tennessee bird brought in by Hurricane Katrina. Almost all those with experience of skuas/jaegers feel that this bird is a SPSK - but this conclusion was drawn from a much larger series of images - click here to see them - of a bird seen in windy conditions and that flew around in front of the photographer/observers, banking etc.
I wonder what ID conclusions might have been drawn had the ONLY images available of this bird been the two shots shown below (with permission)?:
- I feel that many of the structural features mentioned in the discussion of the TX Nov 2004 bird would have lead assessors to feel it could not be called a SPSK. This shows how important it is in this case to have those extra photos, and that a bird that looks clearly like a SPSK in one photo can look far less-so in another photo.
Here's the November 06 2004 Texas bird again :-
- adjusted to match the angle and general lighting of the above TN pics.
I don't claim that these pics match the TN bird, but I do feel that they are fairly close. Keep in mind that the tertials/humerals of the TX bird are heavily worn or perhaps undergoing replacement (see original page here)- this affects the jizz of the wing base. Also, the active molt in the inner primaries is clearly affecting the jizz of this part of the wing:
Sadly the TX bird was seen on a flat-calm day and it flew past without changing flight style - no banks or turns to clarify the jizz. Clearly this page does not advance the ID of the TX bird, but I feel that it does show how a SPSK can look VERY different at certain angles.
David Sibley has built an interesting and generally helpful web page addressing the SPSK vs POJA shape issue; click here to visit this page. I want to reiterate David's comment in the penultimate paragraph that the images are meant to be considered silhuettes only. I personally wish that David had not chosen to give the superb POJA illustrations a pale underbody, as this creates the impression that such birds (pale body with dark, unbarred underwing coverts) are known to exist - there is no such evidence at this time.
I find myself agreeing with David's last sentence, perhaps with this added emphasis: " So the Texas bird seems from these pics to have the shape of a jaeger and the plumage of a skua, and which feature is more reliable and carries more weight in the identification is still an open question."