_Vermivora peregrina._ Tennessee Warbler.--Weights: 1 adult male, 10.9, very fat; 1 immature male, 12.9, very fat; 2 adult females, 9.1, 12.5, moderately fat and very fat. The relative scarcity of Tennessee Warblers in the sample is surprising. They are common in the area in spring. _Vermivora c. celata._ Orange-crowned Warbler.--Weights: 9 adult males, mean 8.8 (7.7-10.9), little fat to fat; 13 immature males, mean 8.92 ± .15, S. D. .53, little fat to fat; 5 adult females, mean 8.8 (8.3-10.3), little fat to moderately fat; 17 immature females, mean 9.13 ± .08, S. D. .72, little fat to fat. Of the 19 Orange-crowned Warblers killed on October 7, 11 had little fat, 6 were moderately fat, and only 2 were fat. No one-night sample of any other warbler killed at Topeka had less fat than this group of warblers. Furthermore, our sample (including 11 males) from October 7 (all sex- and age-classes) averaged 8.81 grams; the sample of 13 (including only 4 males) from October 1 averaged 9.1 grams. If one can assume, for any one species, that individuals undertake nocturnal migration only when they are physiologically ready, and this includes a certain amount of fat as a fuel source (Wolfson, 1954), then this further assumption seems justified: birds killed in migration with little fat must have flown longer or farther or both than birds killed with more fat. No further speculation on this point is permissible with our data, but the possibilities for study of future large kills, especially where actual time of death of the birds is known, are obvious. _Vermivora r. ruficapilla._ Nashville Warbler.--More Nashville Warblers were picked up at Topeka than any other species and they are discussed in detail elsewhere in this report. The four sex- and age-classes can be identified with fair accuracy on plumage characteristics alone. Adult males have a large amount of reddish-brown in the crown, not completely veiled by the gray tips of the crown feathers. Immature males have a smaller but distinct crown patch, usually completely veiled. All males, compared with females, are grayer on the sides of the head, have a more nearly white eye-ring, and show clearer yellow on the throat. Adult females differ from immature females in that they more often have a trace of rufous in the crown and tend to be brighter below than the immatures. Of 177 specimens, 20 were very fat, 108 were fat, 46 were moderately fat, and 3 had little fat. _Parula americana._ Parula Warbler.--Weight: 1 adult female, 7.9, fat. _Dendroica petechia aestiva._ Yellow Warbler.--Weights: 1 immature male, 10.2, fat; 3 adult females, 8.8, 9.5, 10.1, moderately fat; 2 immature females, 9.0, 9.4, little fat and fat.