High equitability and coordination of parental care in the Rufous Hornero (Furnarius rufus)

VIVIANA MASSONI; JUAN C. REBOREDA; GABRIELA C. LÓPEZ; M. FLORENCIA ALDATZ

Cusco

Congreso; IX Neotropical Ornithological Congress; 2011

Neotropical Ornithological Society

    Parental care of altricial birds takes time and energy that are taken from the self-maintenance activities and life-expectancy of parents, and is usually related to the social and genetic mating system. In addition to the amount of effort made by each sex, it is important to determine if the partners complement or coordinate their activities, to understand the relative contribution they make. In spite of their abundance, we know very few of the parental care made by Rufous Horneros and our goal was to determine the contribution and coordination of the sexes along all the parental chores of the nesting period in a molecularly sexed population. We video-recorded 59 nests at Chascomús, Bs. As., Argentina, and found that: a) though females carry more mud to the nest at the beginning of the nest building period, both sexes build the nest at the same rate and coordinate between 70 and 80 % of the visits, b) both sexes incubate equally, females only slightly more at the onset of incubation, and the coordination between members of the pair reaches 90 % of the visits, c) males brood a lot, only a little less than females, and between them coordinate 60 % of the visits. Males and females of the Rufous Hornero, therefore, are highly egalitarian in the distribution of parental care duties and, in addition, coordinate the parental effort to a high extent. Together with other reproductive biology information, these results suggest they are genetically monogamous.