Pictures taken by a friend of mine on a recent trip to the island of Svalbard in the Arctic region of Norway
No interactions present.
The only recognised subspecies of Kitti is Rissa tridactyla pollicaris from the N Pacific (which has a hind toe, unlike ours). I'm guessing that the apparent darkness is probably a factor of the exposure or the light.
Flickr pics: http://www.flickr.com/photos/72243477@N00/
Lat/Lng: 78.5, 14.2