Parental care of Elaenia albiceps nestlings in the Andean-Patagonian Forest

GOROSITO, C.A.; TUERO, D.; CUETO, V.R.

Congreso; Ornithological Congress of the Americas, XVII Reunion Argentina de Ornitología, XXIV Congresso Brasileiro de Ornitologia & XCV Annual Meeting of Association of Field Ornithology; 2017

Mostbird species provide biparental care, which is mainly observed in monogamous specieswith altricial nestlings. Biparental care is not always equally shared betweensexes, and females provide more parental care than males. Our aim was study theparental care in Elaenia albiceps,which is a migrant species that reproduces in the Andean-Patagonian Forest during the austral summer. Field work took place inEsquel, Argentina, in two breeding seasons (2015/2016 and 2016/2017). E. albiceps nests were filmed during45-90 minutes when the nestlings were 2-4 days and 9-10 days old (they were closeto becoming fledglings). The provisioning frequency of nestlings by females washigher than the one for males, and both sexes increased their provisioningfrequencies with the age of nestlings. Those females that fed nestlings alone hadthe same provisioning frequency than the females assisted by males. Wedifferentiated males that did not provide parental care, males that had scarce contributionto parental care and males that had provided as much parental care as females.Our results indicate that E. albicepshas a biparental care biased to females, and females can raise a brood withoutcontribution of the male. The great variance in parental care observed amongmales suggests a monogamous mating system with a low paternity certainty, thereforefurther studies about the frequency of extra-pair fertilizations will allow usto assess this hypothesis.