1920 ] Wetmore, Birds of Lake Burford, N. Mex. duo Henslow' Sparrow to the clear, plantive, whistle of the White- throated Sparrow, and the serene, spiritual hymn of the Hermit Thrush. While the simpler, more primitive songs are given forth only during courtship excitement, it is evident that many, especially the more complicated and aesthetic ones, although at their best and sometimes elaborated or extended under court- ship excitement, are often continued and repeated for the mere enjoyment of the performer in his own music. The autumnal recrudescence of the amatory instinct, often displayed in song, is well known. The subject of bird song is one apart by itself, and I have alluded to it in this brief manner merely to round out the classification, made in the beginning of this paper, of display, dance and song — the important features of bird courtship. 98 Pinchiey St., Boston, Mass. OBSERVATIONS ON THE HABITS OF BIRDS AT LAKE BURFORD, NEW MEXICO. BY ALEXANDER WETMORE. (Concluded from p. 247.) 19. Botaurus lentiginosus (Montagu). American Bittern. — One was heard pumping in the rushes several times on the morning of May 29. Another was found at the first of the small lakes in the canyon below on June 11. It was pumping also so that it is possible the Bittern breeds here. 20. Ardea herodias Linnaeus. Great Blue Heron. — Present during migration. Three were seen on May 29, and one on May 30 and June 3. 21. Egretta candidissima candidissima (Gmelin). Snowy Heron. Found at Lake Burford during migration. One was seen at the crossing of the Brazos River below Park View, N. M., on May 23, and another was observed at Lake Burford that evening. Two were noted at the lake on May 26, and another was seen on the morning of June 5. One flew past the cabin several times on the evening of that day and finally alighted in the rushes nearby where it was collected. It was an adult
