Stercorarius longicaudus Childs 1958 30 May Gitmezea River, Cape Sabine, Alaska Maybe 10 in area. Saw a pair give chase to a single bird who paid no attention to them. I would say that they were on territory already 31 May Same. Maybe 3 pairs in study area this year. 1 June Watched pair from our side drive pair across river. When they reached the far shore the attacking pair returned and the invaders out on river bank 4 June While walking across Loon Marsh to T2 This morning at 1050 I observed copulate in this species. When first noted the ♂ was already mounted with wings arced downward in a rather graceful and unusual position ( ). This may position may have been used for balance but it did not so appear. The stiffound "treadwater". There was considerable movement of the tail but I could not see the details from this angle from ten feet. Several times the ♂ grasped the neck feathers of the ♀, a movement which did appear to aid in mountain of balance. At the end the ♂ stood on the ♀ for several seconds just looking around. Then moved off to high