- A scientific team led by the Miguel Hernández University of Elche with the collaboration of the Doñana Biological Station – CSIC has analysed the basic patterns of movements of several populations of griffon vultures in Spain. Their movements are influenced by individual sex, breeding region and other environmental factors
- Results show that the management of these species, which exploit very large areas, cannot be approached at the local level and requires the collaboration of regional and national administrations to implement conservation strategies
A scientific team led by the Miguel Hernández University of Elche, in collaboration with the Doñana Biological Station and the National Museum of Natural Science, both belonging to the Spanish National Research Council (CSIC), has analysed the basic movement patterns of griffon vultures in Spain. This study works with information from several populations of this species, three of them monitored by the EBD-CSIC in Andalusia and Bardenas Reales in Navarra, allowing to obtain data on an unprecedent number of vultures.
The griffon vulture is a key role species in Southern Europe since it provides important ecosystem services through the removal of livestock and wild ungulate remains, at no economic cost and without greenhouse emissions. Along with other scavenger avian species, it has also become an attraction for nature tourism, generating important income for rural economies, especially in the so-called ‘empty Spain'. "Despite its importance, we still know very little about essential aspects of this species movement ecology, which is fundamental to properly manage its conservation", explains José Antonio Donázar, Professor of Research in the Doñana Biological Station – CSIC.
In this study, 127 griffon vultures were GPS-tagged in five different regions of peninsular Spain. The data indicated that the individuals move over very large areas of up to 5,000 km2 on average in a year, but sometimes this area reaches up to 10,000 km2. These birds can also move an average of 1,700 km per month. The data analysis revealed important differences in the roosting area, depending on several factors, such as breeding area, seasonality or individual sex.
For example, individuals from northern breeding regions, (Pyrenees, Ebro) showed smaller homeranges and traveled shorter monthly distances than those from southern ones (Cádiz, Cazorla). The team also detected differences according to the season. In all cases, home-ranges were larger in spring and summer than in winter and autumn, which could be related to difference in flying conditions and food requirements associated with reproduction. Moreover, females showed larger home-ranges and less monthly fidelity than males, indicating that the latter tended to use the similar areas throughout the year. These results could determine, for example, asymmetries of both sexes in the levels of exposure to mortality factors caused by human activities.
Changes in rural societies
"Based on these results, it is of the utmost interest to study in depth how space use patterns vary when environmental conditions change," says José Antonio Donázar. In the long term, according to the researcher, it is essential to predict how the scenarios of radical changes that are taking place in rural economies may affect the viability of scavenger bird populations. "Rural economies are undergoing changes in two ways, which are really two sides of the same coin. On the one hand, we have the intensification of livestock farming and, on the other, rural abandonment, leading to the disappearance of traditional uses and the renaturalisation of large areas of the Iberian Peninsula," he explains. "This will require the long-term monitoring of populations with GPS tagging and the study of individual responses to these changes."
The results obtained from this work demonstrate that the management of species, exploiting such large areas, cannot be approached at a local level. Conservation strategies are needed to guarantee the existence of trophic resources and minimise mortality risks on a continental scale. For this, according to the scientific team, the collaboration of regional and even national administrations will be required to avoid asymmetries in the application, for example, of health regulations related to the elimination of livestock remains.
Jon Morant, Eneko Arrondo, José Antonio Sánchez-Zapata, José Antonio Donázar, Ainara Cortés-Avizanda, Manuel De La Riva, Guillermo Blanco, Félix Martínez, Juan Oltra, Martina Carrete, Antoni Margalida, Pilar Oliva-Vidal, José Maria Martínez, David Serrano, Juan Manuel Pérez-García. Large-scale movement patterns in a social vulture are influenced by seasonality, sex, and breeding region. Ecology and Evolution. DOI: https://doi.org/10.1002/ece3.9817
Estación Biológica de Doñana – CSIChttps://doi.org/10.1002/ece3.9817