Mutual Wattle Ornaments in the South Island Saddleback (Philesturnus carunculatus) Function as Armaments

摘要: Many birds have ornamental traits that are expressed in both sexes. Wattles—colorful fleshy structures hang from the lower bill—are frequent among birds, but remain poorly understood and generally presumed to be under sexual selection. The South Island saddleback (Philesturnus carunculatus) is an endangered bird endemic New Zealand which males females possess wattles. We used behavioral observations, morphological measures, a playback experiment investigate role of wattles saddlebacks during territorial encounters. Wattles were monomorphic when controlled for body mass, became engorged with blood sexes visual displays. In using male song, wattle engorgement was significantly associated intrusions not females. However, female more likely experiments absence their mate, suggesting defense by markedly similar use displays as response supports hypothesis these elaborate function part armaments.