EFFECT OF DROUGHT AND MEGAFIRE IN IBERÁ NATIONAL PARK, CORRIENTES, ON THE REPRODUCTION OF THE IBERÁ SEEDEATER

CATAUDELA, J. FRANCISCO; BROWNE MELANIE; DI BITETTI, MARIO S.; DI GIACOMO, ADRIÁN S.

Gramado

Congreso; II Ornithological Congress of the Americas; 2023

Association of Field Ornithologists

Northeastern Argentina Grasslands have been identified as a biodiversity conservation priority environment particularly for endangered grassland birds. The Iberá Seedeater [Sporophila iberaensis], is a migratory bird, categorized as Endangered by IUCN, endemic to South American flooded grasslands with a restricted distribution. Its only reported breeding site is found within the Iberá wetlands. The main objective of this study was to evaluate the impact that extreme climatic conditions, such as severe droughts and megafires that took place in Corrientes province in early 2022, had on the reproduction of [S. iberaensis]. We have evaluated its main breeding parameters and compared 73 nest attempts during 2022 (drought & post-fire. n=35) and 2018 (normal rains & pre-fire, n=38) breeding seasons. The principal cause of nest failure was predation (55%) and storm-associated falls (12%). We did not find significant differences in daily survival rate, in clutch size, nor in hatching success between years. However, we found differences in predation rate, being lower during the dry season compared to the humid season, with nest predation probabilities of 56% and 79%, respectively. Our results suggest that [S. iberaensis] reproduction was positively affected during the 2022 breeding season with dry and post-fire conditions. These results may have been influenced by a diminution in mortality after fire/drought generated by changes in the mesopredator ensemble or due to a potential increase in food availability for the species as a consequence of the regrowth of vegetation after the megafire.