ML644780998

观察细节

It is difficult to be sure if it is a non-breeding adult or a first-fall male. This bird is likely an adult because of its extensive bay flanks, gray rump, and lack of contrast between the newly molted greater wing coverts and the primary coverts. In fall, male Bay-breasted Warblers show reduced bay coloration on the flanks. Many first-fall males lack bay flanks, instead having rich buff flanks. In both sexes, Formative Plumage is distinguished from Definitive Basic Plumage by showing duller and browner retained juvenile primary coverts contrasting with newer formative greater coverts. First fall birds also have thinner and more pointed (juvenile) outer primaries and rectrices (Pyle 1997a). Its hard to say for certain, but it appears that the outter retrices are quite round on this bird.