Holmes, R 1463 C. melanostos 29 may Barrow, Alaska Call note - but not the gonging drone note (while whistling aggressive chase). Sev. more PP - all seen as mdu - were along Elsin Loya - 1 a Deer ridge. No aerial display seen - but evening was cold & "dark". 30 may I displaying along bluff to John Creek - no PP or other PP were noted. AIR SAC. - in processing 2078 - looked at esophagus - when flattened was 15 mm across + 137 mm long. The diameter of 15 mm was taken at the caudal region. It tapered to 7 mm just in front of the proventriculus. If the esophagus was pinched about 8 cm from the mouth - air blown into it with a spring-bullet - the diameter increased to 35 mm. The "texture" was very elastic & thin. Thus the esophagus may undergo some change at this time - which allows it to be inflated (or at least potentially). More checking (Mark 1) needed for other species so more needed. 31 may - 2078 seen between Wollbrookpit - 1 aerial display seen - otherwise birds spent their feeding.