High coordination and equitative parental effort in the Rufous Hornero

MASSONI, VIVIANA; JUAN CARLOS REBOREDA; GABRIELA CARINA LOPEZ; ALDATZ, MARÍA FLORENCIA

THE CONDOR

COOPER ORNITHOLOGICAL SOC

Año: 2012 vol. 114 p. 564 - 570

0010-5422

Abstract. In temperate regions of the Southern Hemisphere, avian parental care is understudied, in particularfor the neotropical family Furnariidae. We measured rates of nest building, mud carrying, incubation, brooding,feeding, and nest-sanitation behaviors of molecularly sexed Rufous Horneros (Furnarius rufus) nesting in thehumid pampas of Argentina. We also evaluated the coordination of all these behaviors between the partners, andcompared the frequency of uncoordinated behaviors of each sex. Males and females worked equitably throughoutthe nesting cycle with few exceptions: (1) both sexes built the nest, but males supplied somewhat less mud at thebeginning of nest construction, (2) though highly involved in incubating the eggs males did so slightly less oftenthan females during early incubation, (3) even if males also brooded the nestlings, they brooded less often and forslightly briefer periods than did females, and (4) young nestlings were fed less often by males than by females. Wefound no differences in nest-sanitation rates. The proportion of behaviors coordinated between partners performingdifferent parental tasks was very high through the entire nesting cycle. Analysis of the frequency of uncoordinatedbehaviors revealed females were more prone than males to skip turns only at the onset of nest building andthe beginning of the nestling period. The sexes? similar and coordinated effort is probably essential for the buildingof the Rufous Hornero?s remarkable nest and reaching the high rate of nest success that characterizes the species.