Abstract
The color and shape of remiges of first-winter plumage of the Ruddy-breasted CrakePorzana fusca observed in Wakayama Prefecture, Japan in October 2016 were reported in this study. The color of remiges of first-winter plumage was darker than that of body feathers and wing-coverts. The shape of the end of the outer primaries was narrow and sharp. These features are the same as those of remiges of juvenile plumage, and support the findings that P. fusca does not molt remiges and wing-coverts in post-juvenile molt. Therefore, color comparison between remiges and wing-coverts might be a useful tool for estimating the age of P. fusca.
