Following methods described by Louis Bureau (1911, 1913) in France, tabulations were made (1) of the ages at which captivity-reared bob-white quail (Colinus virginianus) dropped their juvenal remiges, and (2) the rates at which post-juvenal replacement primaries grew. These were arranged so as to permit the determination of age in healthy birds from one to five months of age. The degree of individual variation was much greater than that found by Bureau, however, and limits accuracy in age determination after the 10th week. The post-juvenal wing molt began on the birds' 28th day and ended when the quail were 146 to 154 days old. The post-juvenal body molt was found to take place largely between the 70th and 100th days. The juvenal rectrices were renewed from the 62nd to the 122nd days, the new feathers being as long as their longest coverts when the birds were 116 days old. The color of the tarsi varied from pink, at 32 days of age, to straw color at 60 days, and yellow-gray from 83 to 180 days. At six months, the color of the beak was identical with that of adults. Unlike several other game bird species, the flexibility of the lower jaw was not an accurate index to age in bob-whites older than 11 weeks. Rigor mortis and freezing were found to hinder the testing of this criterion.
