Multiple factors associated with nest-site selection in a wetland-specialist, the Wren-like Rushbird ( Phleocryptes melanops )

CHIARADIA, NICOLÁS MARIANO; ISACCH, JUAN PABLO; PRETELLI, MATÍAS GUILLERMO; CARDONI, DANIEL AUGUSTO

EMU

CSIRO PUBLISHING

Año: 2019 p. 1 - 9

0158-4197

Diverse factors may limit nest-site selection; however, nest predation has long been considereda main factor driving nest-site selection in birds. Marsh-nesting birds face a particularlyimportant trade-off between habitat features that impede their vision of the approach ofpotential predators and nest concealment from predators. Here, we analyse how differentecological variables influence nest-site selection in the habitat-specialist Wren-like Rushbird(Phleocryptes melanops) breeding in three different wetlands of the Pampas region of Argentinaover 3 years. Rushbirds selected nest sites with higher heights and denser vegetation, comparedto random sites. Nest height was positively associated with vegetation height and lowervisibility from the point of view of aerial predators, and the nest entrance was oriented towardsthe region with greatest visibility of the nest from the point of view of Rushbirds. Rushbirdsseem to flexibly adjust their nest location in response to high predation risk, building theirnests under structures built by other birds when breeding colonies of herons and gulls(potential nest predators) are present. Initial nest-site selection is performed by males, whichthen attempt to attract females to a rudimentary nest. Females sometimes reject such sites andthe male then selects a new nesting location. Our study highlights the potential for flexible sexdifferences in nest-site selection.