Elucidating patterns of population structure for species with complex life histories, and disentangling the processes driving such patterns, remains a significant analytical challenge. Humpback whale ( Megaptera novaeangliae ) populations display complex genetic structures that have not been fully resolved at all spatial scales. We generated a data set of nuclear markers for 3575 samples spanning the seven breeding stocks and...

A bstract We describe a novel behavior, termed “tail‐up,” observed in humpback whales ( Megaptera novaeangliae ) on wintering grounds on Abrolhos Bank, Brazil. The behavior involves the whale positioned vertically in the water column with its tail in the air. With the exception of calves, tail‐up was observed in all social classes, and its frequency increased through the end of the season. Tail‐ups were recorded in 144 (5.8%)...