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San Sebastián de los Reyes, Spain

Blazquez M.C.,Centro Investigaciones Biologicas Noroeste | Delibes-Mateos M.,University of Porto | Delibes-Mateos M.,Institute Estudios Sociales Avanzados IESA CSIC | Vargas J.M.,University of Malaga | And 3 more authors.
Ecological Indicators | Year: 2016

Turkey Vulture (Cathartes aura) reliance on marine subsidies in coastal Baja California peninsula was quantitatively assessed by analyzing carbon and nitrogen stable isotope ratios in its feathers. Feathers were collected in two separate roosts in a small farm, a small fishing village and an uninhabited beach. We compared among them the isotopic niches of the four populations and also with those of Yellow-footed Seagull (Larus livens), Brown Pelican (Pelecanus occidentalis) and Orange-throated Whiptail lizard (Aspidoscelis hyperythra), used as reference for sympatric marine and terrestrial species. The importance of nutrients of marine origin varied among local close subpopulations, suggesting some spatial segregation. Dominant individuals would be established near predictable sources of food (human settlements), having a mixed terrestrial-marine diet influenced by local human activities (isotopic signature of feathers also indicated the role of human-fed cattle as vulture food). Subordinate individuals would be relegated to wandering along the beaches searching for washed up food, having a diet almost exclusively marine. © 2015 Elsevier Ltd. All rights reserved.

Tobajas J.,Institute Investigacion en Recursos Cinegeticos IREC | Fernandez-de-Simon J.,Institute Investigacion en Recursos Cinegeticos IREC | Fernandez-de-Simon J.,University of Burgundy | Diaz-Ruiz F.,Institute Investigacion en Recursos Cinegeticos IREC | And 3 more authors.
European Journal of Wildlife Research | Year: 2016

How foraging behaviour of predators is influenced by prey abundance is often not clear. Predators may behave as generalist or specialist depending on the relationship between the predator feeding behaviour and prey abundance, known as functional response. The European rabbit (Oryctolagus cuniculus) is a key species for most Iberian vertebrate predators, especially for large raptors such as the eagle owl (Bubo bubo). The eagle owl functional response was analysed in central Iberian Peninsula by fitting different models (null, linear, two asymptotic and two sigmoidal models) between rabbit abundance and rabbit consumption by the eagle owl. Rabbit consumption increased as did its abundance until reaching an asymptote. Rabbit-consumed biomass better fitted to a type II functional response (convex, typical of specialist predators), whereas rabbit frequency in eagle owl diet better fitted to a type III functional response (sigmoidal, typical of generalist predators). Trophic diversity increased as rabbit abundance decreased. The consumption of other prey, such as Iberian hare (Lepus granatensis) and medium-size birds (mainly galliformes and columbiformes), increased as rabbit abundance decreased. The eagle owl is highly dependent on rabbits in central Spain, even at low rabbit abundance. In this situation, the eagle owl diversifies its diet, making it difficult to define the eagle owl as a specialist or as a generalist predator. Therefore, the eagle owl in the centre of the Iberian Peninsula should be rather considered as a facultative predator on wild rabbits. © 2015, Springer-Verlag Berlin Heidelberg.

Parravano A.,University of Los Andes, Venezuela | Parravano A.,Institute Estudios Sociales Avanzados IESA CSIC | Noguera J.A.,Autonomous University of Barcelona | Hermida P.,Autonomous University of Barcelona | Tena-Sanchez J.,Autonomous University of Barcelona
PLoS ONE | Year: 2015

Models of social influence have explored the dynamics of social contagion, imitation, and diffusion of different types of traits, opinions, and conducts. However, few behavioral data indicating social influence dynamics have been obtained from direct observation in "natural"social contexts. The present research provides that kind of evidence in the case of the public expression of political preferences in the city of Barcelona, where thousands of citizens supporting the secession of Catalonia from Spain have placed a Catalan flag in their balconies and windows. Here we present two different studies. 1) During July 2013 we registered the number of flags in 26% of the electoral districts in the city of Barcelona. We find that there is a large dispersion in the density of flags in districts with similar density of pro-independence voters. However, by comparing the moving average to the global mean we find that the density of flags tends to be fostered in electoral districts where there is a clear majority of pro-independence vote, while it is inhibited in the opposite cases. We also show that the distribution of flags in the observed districts deviates significantly from that of an equivalent random distribution. 2) During 17 days around Catalonia's 2013 national holiday we observed the position at balcony resolution of the flags displayed in the facades of a sub-sample of 82 blocks. We compare the 'clustering index' of flags on the facades observed each day to thousands of equivalent random distributions. Again we provide evidence that successive hangings of flags are not independent events but that a local influence mechanism is favoring their clustering. We also find that except for the national holiday day the density of flags tends to be fostered in facades located in electoral districts where there is a clear majority of pro-independence vote. © 2015 Parravano et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Diaz-Ruiz F.,Institute Investigacion en Recursos Cinegeticos IREC | Diaz-Ruiz F.,University of Porto | Delibes-Mateos M.,Institute Investigacion en Recursos Cinegeticos IREC | Delibes-Mateos M.,University of Porto | And 2 more authors.
Annales Zoologici Fennici | Year: 2016

Cage-Trapping is one of the control methods frequently used by hunters to remove red foxes (Vulpes vulpes) in Spain, although its low efficiency and selectivity have been frequently reported. We tested the effect of the combinations of two bait types (live/ dead) and two scent attractants (fox urine/valerian extract) in order to improve the efficiency and selectivity of cage traps in central Spain. The combination of live bait and fox urine increased the efficiency of cage traps to capture red foxes in comparison with live bait alone. None of the experimental treatments led to a significant reduction in the capture rate of non-Target species, selectivity levels were always low (0%-21%) and non-Target species were captured. In view of that, the burden of releasing captured non-Target animals depends ultimately on the trapper. For this reason, the use of cage traps is still questionable for managing foxes in Spain. © Finnish Zoological and Botanical Publishing Board 2016.

Diaz-Ruiz F.,Institute Investigacion en Recursos Cinegeticos | Diaz-Ruiz F.,University of Porto | Caro J.,Institute Investigacion en Recursos Cinegeticos | Delibes-Mateos M.,Institute Investigacion en Recursos Cinegeticos | And 4 more authors.
Journal of Zoology | Year: 2016

Daily activity patterns in mammals depend on food availability, reproductive stage, habitat selection, intraspecific interactions and predation risk, among other factors. Some mammals exhibit behavioral plasticity in activity patterns, which allows them to adapt to environmental changes. A good example of this can be found in the red fox Vulpes vulpes. This species is adapted to living in highly humanized environments, where it is often culled because it may affect human interests (e.g. through the consumption of game species or livestock). We assessed the potential main drivers of the daily activity patterns of the red fox in 12 Iberian Mediterranean areas through the use of camera traps. Among drivers, we considered main prey availability (European wild rabbits Oryctolagus cuniculus), degree of human disturbance (e.g. distance to human settlements, and intensity of predator control) and habitat structure. Our results revealed a predominantly crepuscular and nocturnal activity of foxes with local variations. Although overall fox activity increased with rabbit availability, the temporal overlap with prey activity was on average low, because foxes increased activity when rabbits decreased theirs (twilight-night). Red fox activity rhythms seemed to be determined by human presence where human disturbance is high. In addition, diurnal activity decreased in areas with higher levels of human disturbance (closer to human settlements and high predator control intensity) and increased in dense habitats. Our study shows that daily activity patterns of highly adaptable species are determined by several interacting drivers, resulting in complex behavioral patterns. This suggests that further ecological studies should consider different factors simultaneously for a better understanding of daily activity patterns of wildlife in different landscapes. © 2016 The Zoological Society of London.

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