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Résumé :
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White-tailed Hawks (Geranoaetus albicaudatus) replace their remiges and rectrices in the usual accipitrid fashion. Rectrices are replaced beginning with R1, then usually R2, R3, R4, R6, and R5 last, but with some variation. However, during a nearly 20 yr study of their molts and plumages in south Texas, I have found that during the second prebasic molt they can and do regularly replace some proximal rectrices 2 times. Specifically, 61 (37 males and 24 females) out of 89 hawks having finished this molt had replaced 1–3, rarely 4, proximal central rectrices. Herein, I quantify how often it occurs and for which tail feathers and show several examples of this second replacement. One explanation for this second molt is that the first replacement feathers become worn and frayed and are replaced late in this molt.
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