IDENTIFICATION OF THE BIRD SPECIES THAT DISPERSE NATIVE SEEDS OF THE CHACO SERRANO FOREST IN A NATURE RESERVE OF CENTRAL ARGENTINA

Abstract

Birds are capable of linking ecosystems throughout the dispersion of seeds. Such a role turns them into key elements to mitigate habitat fragmentation effects. However, it has been postulated that only legitimate dispersers may provide this service. In Vaquerías Nature Reserve located in a fragmented landscape of the Chaco Serrano forest, we captured birds between January and April of 2017 and 2018, retrieved whole seeds from their feces, and evaluated their germination to identify the assembly of bird species that serve as seed dispersers in the area. From feces of nine bird species, we retrieved over one hundred seeds of thirteen native plant species. Based on the number of whole seeds recovered from feces and their germinability, we recognized Elaenia parvirostris, Turdus amaurochalinus, Poospiza whitti, Zonotrichia capensis, and Saltator aurantiirostris as seed dispersers of native plants in the reserve. It is worth noting that not all of these species are considered frugivorous and seed dispersers. For example, Zonotrichia capensis and Saltator aurantiirostris have been previously classified as granivorous, and traditionally considered seed predators disregarding their potential role of seed dispersers. However, our results indicate that they may act as legitimate dispersers of some native species. This study highlights the need to further evaluate the functional role as seed dispersers of several bird species that include fruits in their diet, considering not only fruit handling and consumption but also information regarding seed viability and germination.