Transhumance is the traditional livestock practice consisting in the seasonal movement of herds between winter and summer pastures. Transhumance have important effects on the ecosystem functions from local to regional scales. Here, we 1) explored the relationship of vultures to transhumant herds, and 2) tested whether there is a shift on the use of space by vultures due to the decline of transhumance. For that, we first assessed whether vultures follow transhumant herds in two mountain areas with transhumant tradition, Pyrenees (Spain) and Andes (Argentina). Second, we compared both systems to determine whether the impact of transhumance on the use of space of vultures is greater in the area where transhumance is still relevant (Andes) than where this activity is in decline (Pyrenees). For this purpose, we analyzed the use of the summer pastures made by 50 griffon vultures (Gyps fulvus) and 18 Andean condors (Vultur gryphus), as assessed by GPS tracking. Our findings showed that both species respond to transhumance by making greater use of summer pastures when herds are present. A higher proportion of condors made use of summer pastures than griffons, and condors individually made a more intense use of it than griffons. Differences could be explained by the fact that transhumance in the Andes is still important while in the Pyrenees is declining and the amount of carrion provided is lower. Given that the abandonment of traditional activities is a phenomenon underway, it is urgent to evaluate the effects it will have on biodiversity conservation.

This research was funded by Comunidad de Bardenas Reales de Navarra and Project TRASCAR (RTI2018-099609-B-C21-C22; Junta de Andalucía (P18-RT-1321); Spanish Ministry of Economy and Competitiveness and EU/FEDER). This study also forms part of the project DIGITALPAST (TED2021-130005B-C21-C22), MCIN/AEI/ 10.13039/501100011033 with funding from Plan NextGenerationEU. We also thank Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), the Agencia Nacional de Promoción Científica y Tecnológica, PICT 2014-0725, PICT 2021-I-A-00484, the Universidad Nacional del Comahue, project 04/B227 and IAATE Conservation Award). E.A. was supported by La Caixa-Severo Ochoa International PhD Program 2015; Generalitat Valenciana and European Social Fund (APOSTD/2021), and Spanish Ministry of Science, Innovation and Universities Contracts (FJC2021-047885-I). ACA was supported by Emergia contract of Junta de Andalucia, Spain. JG was supported by the Peregrin Fund.