_Plumages._--The plumages and molts of the olive warbler are as distinctive as its nest and eggs. The sexes are not quite alike in juvenal plumage. Ridgway (1902) describes the young male as "pileum, hindneck, back, scapulars, rump, and upper tail-coverts plain dull olive or brownish olive; supra-auricular region and sides of neck dull yellowish buffy, the latter tinged with olive; chin, throat, and chest dull yellowish buffy; otherwise like adult female." And of the young female, "similar to the young male but paler and grayer above; supra-auricular and post-auricular regions pale brownish buffy; chin, throat, and chest still paler buffy, the chin and upper throat dull buffy whitish." The white tips of the greater wing coverts are tinged with yellowish. I have not been able to trace the postjuvenal molt in the series I have examined but it apparently occurs in July and produces very little change, young birds of both sexes in their first winter plumage closely resembling the adult female at that season, though the crown and nape are grayer and the throat and breast are paler. I can find no evidence of a prenuptial molt. Young males evidently breed in this plumage and do not acquire the fully adult plumage until their second fall, or perhaps later. In Brewster's series, collected in March, three males are in this condition, of which he (1882) says that "two of them, although in unworn dress, are absolutely undistinguishable from adults of the opposite sex; the third (No. 77), however, has the throat appreciably tinged with the brownish-saffron of the adult male." This last may be a bird that is one year older, for Ridgway (1902) describes the "second year" male as "identical in coloration with the adult female." Judging from the series that I have examined, including all of Brewster's birds, I am inclined to think that the adult winter plumage is acquired at the first postnuptial molt, or when the bird is a little over one year old. There can be no doubt, however, that young males breed in this immature plumage, for Price (1895) secured a pair that were feeding a brood of young, and the "male was not in fully adult plumage and was very similar in coloration to the female." Swarth (1904) writes: "The male bird breeds in the immature plumage, for on June 21, 1902, I assisted O. W. Howard in securing a nest, containing four eggs, the parents of which were indistinguishable in color and markings. * * * I was surprised at the large proportion of birds in this immature plumage that were seen. At a very liberal estimate I should say that the males in adult plumage comprised barely a third of the birds seen in the spring."