Maker 1959 Calcarus lapponicus May 22 Patwegen River. Whaquutauo as usual. Males displaying when we arrived. Saw 2 copulate this morning. Both had same pattern, O chased & in very close zig zag flight. She landed & they copulated. She was a precopulatory display on the DIO part which I didn't see distinctly except to note that his mouth was open & he held unmoved, wraps partly opened & fluttered same. In both instance a second male came over and attempted to horn in. May 23 All over - usually noted paired today. Much aerial displaying May 25 Whaquutauo as usual, males singing & displaying all over. Saw female with meeting material. One from trapped had very large ova. May 26 Whaquutauo May 27 " Tried to chase one pair off. its territory today. Couldn't. They will push so far - a hundred feet or so & then doubled back. The adjacent male gave a wing display & what I presume was Territory boundary & they flew back past me. May 31 Barrow. - A few of these have arrived at Barrow. Occasional pairs were seen on a