I saw this Bumblebee in several locations on North and South Uist over the past couple of weeks. I'd appreciate a confirmation of my identifcation please. I think it is Bombus muscorum (thanks to the brilliant NHM key!) It was feeding on Dactylorhiza incarnata ssp. coccinea.
I also watched a Bombus distinguendus exploring a dry stone wall at Tobha Mor on south Uist, which was a real treat, though no pics unfortunately...
I also used the NHM guide and I ended up with bombus pascuorum Queen/worker. I guess it depends on how you interpret the photo. I see the thorax as orange and the first segment of the abdomen as white, but yellow was the only offered option. Other abdomen segments black. A light yellow segment could easily appear white if the photo is slightly over-exposed.
The colour patterns for pascuorum are shown at the link below
and the queen/worker (southern form) rightmost picture seems to match your bee. On the other hand, colour schemes for muscorum are shown here
and I don't see any that match your photo for abdominal pattern.
The balding ginger thorax (and what looks like a white tail-tip) are very distinctive markings, but it isn't clear from your (i.e. Jen's) photo whether it is only the tip that is pale?
My mistake, looking at the photo again it does look like most of the tail is pale so Bombus muscorum is the likely candidate. Google image results for comparison.
Thank you both for your comments. Although it is not clear from this photograph, due to the abdomen being curled round under the bee, I recall from my multiple observations of these in flight that the abdomen was almost entirely a pale yellow and the thorax a chestnut red brown, very hairy with no apparent bald patch. No obvious black stripes on the abdomen either but I am not sure what colour the tip of the tail was. The colour variants for the North West and Islands populations of B. muscurom do seem to fit best for what I observed.
Hopefully next time I will get a better picture!
Many thanks, Jen