New Publication on vultures and human activities!

Arrondo, E, Sanz-Aguilar, A., Pérez-Garcia, J., Cortés-Avizanda, A., Sánchez-Zapata, J.A., Donazár, J.A. 2020 Landscape anthropization shapes the survival of a top avian scavenger Biodiversity and Conservation.pp 1–15  https://doi.org/10.1007/s10531-020-01942-6)

Photo: M. Gomila

Abstract. Events of non-natural mortality in human-dominated landscapes are especially challenging for populations of large vertebrates with K strategies. Among birds, vultures are one of the most threatened groups experiencing sharp population declines due to non-natural mortality. Factors causing non-natural mortality are usually studied separately. However, the potential use of an integrated index able to predict large-scale mortality risks of avian scavengers could be especially useful for planning conservation strategies.
Here, we used the Human Footprint index to examine the impact of landscape anthropization on the survival rates of 66 GPS-tagged adult Eurasian griffon vultures (Gyps fulvus) in two Spanish regions. Foraging in more anthropized areas resulted in a significantly higher individual mortality risk mainly due to collisions with vehicles, poisonings, electrocutions and fatalities with wind turbines. Mean yearly survival rates were estimated at 0.817 ± 0.043 SE and 0.968 ± 0.018 SE for individuals from the more and less anthropized regions, respectively. Additional research should investigate whether some vulture populations could be acting as sinks unnoticed due to metapopulation dynamics. From a broader point of view, our study shows that a straightforward Human Footprint was a useful index to predict the survival of top scavengers and can be highly applicable to planning large-scale conservation measures.
A recent press release (in Spanish) here

Upcoming Conference at the University of Valencia

GEDA was invited to present a conference at the University of Valencia on seabird survival Thursday the 19th of September 2019.

New Publication on seabird mortality and fishery !

Genovart M, Bécares J, Igual J-M, Martinez-Abrain, A., Escandell, R., Sánchez, A., Rodriguez, R., Arcos, J.-M., Oro, D. 2018 Differentialadult survival at close seabird colonies: The importance of spatial foragingsegregation and bycatch risk during the breeding season. Global Change Biology.00:1–13. https://doi.org/10.1111/gcb.13997

Abstract: Marine megafauna, including seabirds, are critically affected by fisheries bycatch. However, bycatch risk may differ on temporal and spatial scales due to the uneven distribution and effort of fleets operating different fishing gear, and to focal species distribution and foraging behavior. Scopoli's shearwater Calonectris diomedea is a long-lived seabird that experiences high bycatch rates in longline fisheries and strong population-level impacts due to this type of anthropogenic mortality. Analyzing a long-term dataset on individual monitoring, we compared adult survival (by means of multi-event capture–recapture models) among three close predator-free Mediterranean colonies of the species. Unexpectedly for a long-lived organism, adult survival varied among colonies. We explored potential causes of this differential survival by (1) measuring egg volume as a proxy of food availability and parental condition; (2) building a specific longline bycatch risk map for the species; and (3) assessing the distribution patterns of breeding birds from the three study colonies via GPS tracking. Egg volume was very similar between colonies over time, suggesting that environmental variability related to habitat foraging suitability was not the main cause of differential survival. On the other hand, differences in foraging movements among individuals from the three colonies expose them to differential mortality risk, which likely influenced the observed differences in adult survival. The overlap of information obtained by the generation of specific bycatch risk maps, the quantification of population demographic parameters, and the foraging spatial analysis should inform managers about differential sensitivity to the anthropogenic impact at mesoscale level and guide decisions depending on the spatial configuration of local populations. The approach would apply and should be considered in any species where foraging distribution is colony-specific and mortality risk varies spatially. 

You can see more information in the Press Note by IMEDEA here (in Spanish)