Ibera Seedeater (Sporophila iberaensis), version 1.0

ADRIAN S. DI GIACOMO; CECILIA KOPUCHIAN; MELANIE BROWNE; LEONARDO CAMPAGNA

Birds of the World

Cornell Lab of Ornithology

Lugar: Ithaca; Año: 2023

2771-3105

bera Seedeater (Sporophila iberaensis) occurs in wet grasslands of southern South America. It was first observed in 2001, but was described in 2016 after studying its population in Esteros del Iberá (Iberá Marshes), Corrientes Argentina (1). The name Sporophila iberaensis or Ibera Seedeater refers to the Iberá marshes, the only breeding site known to date. Adult males were first thought to be juveniles of other Sporophila species, but after observing adults paired and breeding with females, defending territories, and presenting a song that did not correspond to other know Sporophila species, it was described as a new species of capuchino seedeater.Capuchino seedeaters are Sporophila species that are smaller than the other members of the genus and characterized by cinnamon—based plumage color patterns, little differentiation in size and shape, with similar females in all species, and males differing in coloration and vocalizations (2, 3). The capuchino seedeaters represent a recent and rapid avian radiation, with strong divergence in male song and plumage patterns, despite remarkably low ecological and genomic divergence (3, 4, 5). A genomic analysis of the capuchino group shows Sporophila iberaensis is in the early stages of speciation (6). However, despite breeding in sympatry in the Esteros del Iberá region with the Tawny-bellied Seedeater (Sporophila hypoxantha), Sporophila iberaensis mates assortatively and remains genetically distinct (6). Males of these two species differ in coloration and song, but females are indistinguishable in their coloration. Females likely use both coloration and song to select mates, demonstrating strong assortative mating despite these two species holding neighboring breeding territories, breeding synchronously, and foraging together for the same seeds.Because this is a relatively newly described species, many aspects of its life history remain to be studied as of 2023. Some ongoing research is aimed at discovering migratory routes, threats to their conservation, and new insights on the speciation and hybridization of this species and its allies.