National policies raise ecological frontiers

    An investigation by seven Spanish and Portuguese researchers on the behavior of griffon and black vultures in the Iberian Peninsula warns that the application of different environmental policies in neighboring countries creates almost insurmountable ecological frontiers.

    Political boundaries can represent ecological barriers due to differences in wildlife management policies. In the European Union, these differences could be expected to be minimal, as all countries must comply with common directives issued by the European Commission. However, the principle of subsidiarity can lead to an uneven assimilation of European Union regulations, which can have an impact on biodiversity conservation due to uneven legislation in neighboring countries, particularly in the case of highly mobile organisms. . Here we address this issue, by analyzing how EU regulations issued in response to the Bovine Spongiform Encephalopathy (BSE) crisis differentially affected vulture conservation in Portugal and Spain. Taking advantage of intensive GPS tracking of 60 griffon vultures (Gyps fulvus) and 11 black vultures (Aegypius monachus) from Spain, we find that the Spanish-Portuguese border acts as a quasi-impermeable barrier. Indeed, there was a precipitous decline in the number of vulture sites across the Spanish-Portuguese border, for which the models show this was unlikely to be related to differences in land use or topography. Instead, the pattern found was probably due to differences in the availability of trophic resources, that is, carrion from extensive livestock farming, as a result of the differential application of European health legislation. Overall, these results should be seen as a red flag for policy makers and conservation managers, highlighting the need for further integration of health and environmental policies at the European level.
    Ecological Frontiers

    Eneko Arrondo, Marcos Moleóna, Ainara Cortés-Avizanda, José Jiménez, Pedro Beja, José A. Sánchez-Zapata, José A. Donázar. Invisible barriers: Differential sanitary regulations constrain vulture movements across country borders. Biological Conservation 219, 46-52 (2018).