The impact of livestock on Argentina's globally threatened grassland birds

ADRIÁN S. DI GIACOMO; DI GIACOMO, ALEJANDRO; BROWNE, M.; FLORENCIA M. PUCHETA

Gramado

Congreso; II Ornithological Congress of the Americas = XII Congreso de Ornitología Neotropical = XXVIII Congresso Brasileiro de Ornitología = Assoaciation of Field Ornithologits Annual Meeting; 2023

Sociedade Brasileira de Ornitologia & Association of Field Ornithologists

Threats to grassland birds are mainly related to land use change for crops and afforestation. However, the use of grasslands for cattle ranching could affect some species that have very specific breeding habitat requirements, such as threatened species. To evaluate the impact of current cattle ranching on threatened grassland bird populations in northeastern Argentina, we compared the results obtained in reproductive studies conducted in cattle ranches and protected areas for: Strange-tailed Tyrant Alectrurus risora, Vulnerable IUCN); Saffron-cowled Blackbird Xanthopsar flavus, Endangered IUCN; and Capuchino Seedeaters Sporophila spp., Vulnerable-Endangered IUCN. We found that the nesting sites of these species are very restricted spatially in grasslands with livestock use. In addition, density of nests and reproductive success in cattle grasslands were consistently lower than in protected areas. Factors contributing to the negative impact of cattle ranching on threatened grassland birds in NE Argentina are related to increased burning, use of feeders, use of agrochemicals, changes in nest predator communities, and increased brood parasitism. To conserve populations of threatened grassland birds in cattle ranches, the creation of small refuges under livestock exclusion that guarantee bird reproduction is recommended, along with the management of the surrounding grasslands with low livestock rates, elimination of feeders and agrochemicals, and low frequency of fires.