_Field marks._--The golden-winged warbler is easy to recognize; it is the only warbler that combines a blue-gray back and yellow in the wing. In the two other common warblers with a black throat, the black-throated blue and the black-throated green, the black runs down the sides a little way so that the white of the breast comes up in a peak in the middle of the breast, whereas in the goldenwing the line of division between the black and white runs straight across. From directly below, the goldenwing appears wholly black and white, and from this angle is marked like a chickadee, but a glance at its long, needle-sharp bill proclaims it a warbler of the genus _Vermivora_. _Enemies._--Prowling mammals, the enemies of ground-nesting birds, and predatory hawks are a danger to the bird. In its relation to the cowbird, Friedmann (1929) reports the bird as "a very uncommon victim." He says: "I have only six definite records, but the species is listed as a molothrine victim by Bendire and by Short. As many as four eggs of the Cowbird have been found in a single nest of this Warbler." _Fall_ and _winter_.--We lose sight of the goldenwing early in the season. Silent amid the dense foliage of July and August, the bird is rarely seen. During the years between 1907 and 1920, when I kept a daily record of birds seen, I met it only four times in August and only twice in September, the latest September 12. Dr. Alexander F. Skutch sends to A. C. Bent the following account of the bird in its winter quarters: "I am familiar with the golden-winged warbler in its winter home only in Costa Rica. In this country it winters on the Caribbean slope from the lowlands up to about 6,000 feet above sea-level, and on the Pacific slope at least in the region between 2,000 and 4,000 feet. While it appears to be nowhere abundant, I found it most numerous at Vara Blanca, on the northern slope of the Cordillera Central at an elevation of about 5,500 feet. Here on one day--November 2, 1937--I saw three individuals, the greatest number I have ever recorded. This is a region of dense vegetation, subject to much cloudiness and long-continued, often violent rainstorms--one of the wettest districts of all Central America. Most of the published records are from this generally wet side of the country. Yet the bird winters sparingly in the Basin of El General on the Pacific slope, which during the first 3 months of the year may be nearly rainless. While in the Tropics, it appears never to associate with others of its own kind, but at times may roam about with mixed flocks of other small birds. It may forage among low, fairly dense, second-growth thickets, or among the tangled vegetation at the forest's edge, or at times in the forest itself, or in groves of tall trees, high above the ground. It investigates the curled dead leaves caught up among the branches, and devours such small creatures as it finds lurking in their folds. I have not heard it sing while in its winter home.