Reproductive biology of the Iberá Seedeater (Sporophila iberaensis)

The Iberá Seedeater (Sporophila iberaensis, Di Giacomo & Kopuchian 2015) is a recently described species for science that inhabits northeastern Argentina, southern Paraguay, eastern Bolivia and central Brazil. It is categorized as “Endangered” by the IUCN. The aim of this study was to investigate the reproductive biology of S. iberaensis for the first time. Between November 2016 and January 2017, we monitored 19 nests located in the flooded area around marshes. The plants supporting nests were Paspalum durifolium (Poaceae) and Cladium jamaicense (Cyperaceae). The clutch size was 1.9 ± 0.52 (SD) eggs (n=12), the mean number of nestlings per nest was 1.8 ± 0.38 (SD, n=13), and 37% of the nests produced fledglings. The daily survival rate was 0.943 ± 0.021 (SE, n=14), and the estimated probability of survival for the whole reproductive cycle was 26% (23 days). Nest failure was due to nest destruction by storms (55%), predation (36%) and abandonment (9%). Only the female built the nest and incubated; however the male participated in nestling provisioning. Differences in reproductive parameters between S. iberaensis and other seedeater species (S. hypoxantha) breeding in the same locality will be discussed.