Sexual dichromatism in species of the family Furnariidae

KOPUCHIAN, CECILIA; TUBARO, PABLO LUIS

Maturín, Venezuela

Congreso; VIII Congreso de Ornitología Neotropical; 2007

Sociedad de Ornitología Neotropical

Furnariids represent a group of exclusively Neotropical birds, which are exceptionally diverse, despite their rather dull plumage. In general, sexes are considered monomorphic in size and color, but some authors mentioned that in some species of this family females are slightly paler than their respective males. These observations were made from looking at specimens by direct human observation. The objective of our study was to assess quantitatively if there were differences in male and female coloration, using an objective method. For this, we take spectral measures of 11 body regions in museum study skins of Phleocryptes melanops (N=47), Schoeniophylax phryganophila (N=33) and Furnarius rufus (N=39) using a reflectance spectrometer. We compared spectral variables between sexes for each species separately through 1 way ANOVA’s. We have found that the brightness of chest coloration is significantly different (p <0.05) between sexes in Phleocryptes melanops and Schoeniophylax phryganophila. Contrary with we would have expected we obtained higher brightness values for females than for males. To our knowledge, this is the first report of sexual dichromatism in family Furnariidae based in an objective method. Different hypothesis of the causes of this effect are analyzed.