From the nest towards the chick produced: challenges of a salt marsh Neotropical passerine

Long-term monitoring is scarce in Neotropics, although necessary to understand the effects involving climate changes. Formicivora acutirostris is a rare member of its family that inhabits wetlands and the only to inhabit daily tidal wetlands (salt marshes). The objective of this study is to relate the results of 11 years of monitoring reproductive aspects of the species with limitations imposed by the tides. The study was carried out between 2006 and 2017 with monthly campaigns, monitoring of 12 to 37 territories per year, and banded all individuals. To estimate the reproductive phenology, we considered the laying of the first egg, to productivity, we counted the nestlings that have attained independence, and the reproductive success is the number of nests in which at least one chick was produced. The reproductive phenology (n=322 nests) extends from August (n=1) to February (n=5), with peaks in October (n=77) and December (n=93). The annual productivity obtained was between none to 29 chicks produced and the average reproductive success was 31.2%. The most frequent causes of nest failure were predation (38.4%) and flooding (27.0%). Causes related to climate change (flooding, wind, and heat) overcome predation (43.3%). The percentage of nests lost by flooding is higher in months with highest tides (October and November). Most chicks out of the nest reaches independence (72%). Many drown in the first day out of the nest. The projected increase in sea level by climate changes may increase reproductive failure of the species.