Milton B. Trautman (1940), speaking of the spring migration at Buckeye Lake, Ohio, shows that the male birds are preponderant in the earliest flights. He says: "The first spring arrivals, chiefly males, were noted between April 16 and 30, and between May 1 and 5, 2 to 15 birds, mostly males, could be daily noted. The peak of migration usually lasted from May 6 to May 18, and then from 3 to 42 individuals, consisting of a few old males and the remainder females and young males, were daily observed. On May 18 or shortly thereafter a decided lessening in numbers occurred, and by May 23 all except an occasional straggler had left." _Courtship._--Forbush (1929) gives this hint of courtship, which resembles the activities of most warblers at this season: "When the females arrive there is much agitation, and often a long-continued intermittent pursuit, with much song and fluttering of black and white plumage, and much interference from rival males before the happy pair are united and begin nesting." _Nesting._--The black-and-white warbler usually builds its nest on the ground, tucking it away against a shrub or tree, or even under the shelter of an overhanging stone or bank. The nest is generally concealed among an accumulation of dead leaves which, arching over it, hides it from above. It is made, according to A. C. Bent (MS.), "of dry leaves, coarse grass, strips of inner bark, pine needles and rootlets, and is lined with finer grasses and rootlets and horsehair." I have seen a nest made chiefly of pine needles on a base of dry leaves. Henry Mousley (1916), writing of Hatley, Quebec, mentions moss as a component part of the nest, and says of three nests that they were all "heavily lined with long black and white horse hairs," a peculiarity of coloration mentioned in one of Mr. Bent's nests. Thomas D. Burleigh (1927b) speaks of a nest in Pennsylvania "built of dead leaves and rhododendron berry stems, lined with fine black rootlets and a few white hairs." H. H. Brimley (1941) describes an exceptional nest. He says: "There was no particular departure from normal in its construction except for the fact that it was lined with a mixture of fine rootlets and very fine copper wire, such as is used in telephone cables. Fragments of such cable, discarded by repair men, were found nearby where a telephone line ran through the woods."