First nest description of the Iberá Seedeater (Sporophila iberaensis)

Abstract

ABSTRACT The southern capuchino seedeaters constitute a rapid radiation of finch-like birds that inhabit Neotropical grasslands in continental South America. While capuchinos are highly sympatric, the mechanisms allowing them to breed in sympatry, such as patterns of microhabitat use, remain largely unknown. We provide the first nesting account of the Ibera Seedeater (Sporophila iberaensis), a recently discovered capuchino species that breeds exclusively in the Ibera wetlands of northeastern Argentina, and compare its nesting habits to those of other members of the capuchino radiation. From November 2016 to January 2017, we located and monitored 25 Ibera Seedeater nests. The Ibera Seedeater constructs open-cup nests in clumps of grass on the margins of flooded habitat and lays an average of 2 eggs per clutch. Like other capuchino species, females participate in nest construction and incubation, while both sexes provision offspring. Despite similarities in nest architecture, the Ibera Seedeater differs in ...