Erolia melanotus January 17, 1962 Voth's Area, Pt. Barrow at 1430, seen at southeastern end of Voth's area and at 1500, one seen at Voth's area next to "Little Freeway." No display. In both instances just fed. June 22, 1962: On road east of trap line IV+X; flock 64 (at least) feeding on road and adjacent hillsides. When started, moved away in a flock under control and moved in a circle coming back down in the same area. June 23, 1962, Trap line IV+X, Pt. Barrow; flock has increased (according to Holmes) to about eighty and has moved across the pipe line and are still feeding. Holmes says they are all males. Significance? "Drum Area" just above trap line IX; male went through the territorial display of flying up and down in an "undulating" wave motion emitting the low booming sound on the upbeat. The wings were flapped on the upbeat and then it would glide downward. A female was sitting nearby, but I failed to locate the nest. Several other males were nearby feeding; they were associated with this flock mentioned earlier. Postural Undulating Flight in territorial display. [sketch of undulating flight pattern labeled "Polygon"] June 24, Central marsh near Trap line VII; male glided over ground with its gular pouch filled emitting that long trill.