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Human footprint and vulture mortality

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, the Human Footprint index was used 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 and 0.968 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, this 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. informacion[at] Arrondo et al (2020) Landscape anthropization shapes the survival of a top avian scavenger. Biodivers Conserv.
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Parasitoidism of host flies by parasitoid wasps in Spain

Parasitoidism of host flies by parasitoid wasps in Spain

Parasitoid wasps may act as hyperparasites and sometimes regulate the populations of their hosts by a top-down dynamic. Nasonia vitripennis  is a generalist gregarious parasitoid that parasitizes several host flies, including the blowfly Protocalliphora, which in turn parasitizes bird nestlings. Nonetheless, the ecological factors underlying N. vitripennis prevalence and parasitoidism intensity on its hosts in natural populations are poorly understood. The prevalence of N. vitripennis in Protocalliphora azurea puparia parasitizing wild populations of pied flycatcher Ficedula hypoleuca and blue tit Cyanistes caeruleus birds was studied in two Mediterranean areas in central and southern Spain. Evidence was found that the prevalence of N. vitripennis was higher in moist habitats in southern Spain. A host-dependent effect was found, since the greater the number of P. azurea puparia, the greater the probability and rate of parasitoidism by the wasp. Results also suggest that N. vitripennis parasitizes more P. azurea puparia in blue tit nests than in pied flycatcher nests as a consequence of a higher load of these flies in the former. Based on the high prevalence of N. vitripennis in P. azurea puparia in nature, this study proposes that this wasp may regulate blowfly populations, with possible positive effects on the reproduction of both bird species. informacion[at] Garrido-Bautista et al. (2019). Variation in parasitoidism of Protocalliphora azurea (Diptera: Calliphoridae) by Nasonia vitripennis (Hymenoptera: Pteromalidae) in Spain. Parasitol Res