Remsen, J.V. 1975 Bewick's Swan Olor bewickii Jan. 15 across the culmen and at its base. (cont) frontal view - Red Bluff Bewick's MV2 Whooper These details were studied by all present for over two hours and all agreed that the bird was a Bewick's from the information we had available. Although the bird was 100+ yds away, with the telescopes we were able to fill (nearly) the screen with the bird in excellent morning back-lighting for study. The only problem was that the bird spent 75% of its time with head buried on back (sleeping) or underwater. The only characteristic which made us hesitate was size, but according to Delacour's measurements, some Bewick's are as large as nearly the largest Whistlings: wing culmen tarsus Bewick's 515-535 90-100 90-105 all Whistling 510-575 90-100 95-115 These measurements are given for the nominate, western race, C.b. bewickii (especially culmen length) which is supposed to average smaller than the more likely race to occur in W. North America, C.b. jankowskii, which breeds to the edge of the Bering Sea. Thus jankowskii might be expected to be larger than Whistling.