Display flight and mechanical sounds of the Andean Negrito (Lessonia oreas), with comments on the basic structure of flight displays in Fluvicoline flycatchers

ARETA JI; MILLER E

ORNITOLOGIA NEOTROPICAL

NEOTROPICAL ORNITHOLOGICAL SOC

Lugar: ALEMANIA; Año: 2014 vol. 25 p. 95 - 105

1075-4377

We describe the display of the Andean Negrito (Lessonia oreas). The display consists of three parts: perched tsi notes, diagonal flight with tic notes, and turn and descent with trrrrrrrrrr wing-whirr and psie note. The wing-whirr appears to be a loud mechanical sound heretofore unknown in the species but consistent with the species? phylogenetic position in the Lessonia-Knipolegus clade. Flight displays are widespread in the tyrant flycatchers. The most conspicuous displays occur in the Fluvicolinae, especially in Fluvicolini and Xolmini. The flight displays of some Knipolegus (at least striaticeps, aterrimus and hudsoni) and Lessonia (at least oreas) appear to share homologous vocal and mechanical sounds (perched notes; flight notes; descent with mechanical sound and sharp vocal note). The inferred loss of display in some Knipolegus species in previous works may partly be a sampling artifact. If Lessonia is sister to Knipolegus, flight displays with mechanical sounds would be the ancestral condition for the group. Deep behavioral homologies in the Xolmini are suggested by observations on the Rusty-backed Monjita (Neoxolmis rubetra) and replacement of mechanical sounds by ritualized elevation and freezing of wings in the display of the Spot-billed Ground-tyrant (Muscisaxicola maculirostris). The sub-apical portion of inner vanes of the eighth and ninth primaries are more concave in the Andean Negrito than in the Austral Negrito (L. rufa) and feather profile is slightly concave in the former and slightly straight or convex in the latter. These differences suggest that these taxa differ in flight displays and potentially in mechanical sounds and are thus correctly considered as different species.