Entity

Time filter

Source Type


Bros V.,Oficina Tecnica de Parcs Naturals | Torre I.,Museu de Granollers Ciencies Naturals | Santos X.,University of Porto
Ecological Research | Year: 2015

Land snails are an important component of biodiversity but the information regarding the factors that influence their distribution is very incomplete or anecdotal in most geographic areas. In this article our aim was to uncover environmental factors that influence the distribution and diversity of a Gastropoda community in a Mediterranean Reserve (Collserola Natural Park, Barcelona). Fieldwork was conducted from 2001 to 2003, andwe systematically sampled all 1 km2 UTM squares throughout the park by randomly selecting at least one 200 m2 plot within each square. We used a community-based approach to analyse the relationships between 61 Gastropod species distributions and environmental predictors by means of Redundancy Analysis (RDA). Our results highlighted that the land snail community was affected by the environmental predictors (even for short gradients), but their influence was low according to the explained variance (30 %). Climate and habitat predictors were more important than the spatial variables in determining the community composition and diversity. 48 out of 61 (78.7 %) land snail species showed significant responses to the environmental gradients with an association of specialist species with particular habitat types. Collserola is a reserve surrounded by urbanised areas and affected by multiple anthropogenic threats mostly related to habitat transformation. The high degree of specialisation within the Gastropoda community suggests that the restoration of heterogeneous landscapes would be useful to conserve and restore terrestrial mollusc diversity in Collserola. This study can help stakeholders to make decisions related to landscape planning and habitat transformation. © 2015 The Ecological Society of Japan Source


Roitberg E.S.,University of Koblenz-Landau | Eplanova G.V.,Russian Academy of Sciences | Kotenko T.I.,Ukrainian Academy of Sciences | Amat F.,Museu de Granollers Ciencies Naturals | And 5 more authors.
Journal of Evolutionary Biology | Year: 2015

The fecundity-advantage hypothesis (FAH) explains larger female size relative to male size as a correlated response to fecundity selection. We explored FAH by investigating geographic variation in female reproductive output and its relation to sexual size dimorphism (SSD) in Lacerta agilis, an oviparous lizard occupying a major part of temperate Eurasia. We analysed how sex-specific body size and SSD are associated with two putative indicators of fecundity selection intensity (clutch size and the slope of the clutch size-female size relationship) and with two climatic variables throughout the species range and across two widespread evolutionary lineages. Variation within the lineages provides no support for FAH. In contrast, the divergence between the lineages is in line with FAH: the lineage with consistently female-biased SSD (L. a. agilis) exhibits higher clutch size and steeper fecundity slope than the lineage with an inconsistent and variable SSD (L. a. exigua). L. a. agilis shows lower offspring size (egg mass, hatchling mass) and higher clutch mass relative to female mass than L. a. exigua, that is both possible ways to enhance offspring number are exerted. As the SSD difference is due to male size (smaller males in L. a. agilis), fecundity selection favouring larger females, together with viability selection for smaller size in both sexes, would explain the female-biased SSD and reproductive characteristics of L. a. agilis. The pattern of intraspecific life-history divergence in L. agilis is strikingly similar to that between oviparous and viviparous populations of a related species Zootoca vivipara. Evolutionary implications of this parallelism are discussed. © 2015 European Society For Evolutionary Biology. Source


Diaz M.,Institute Recursos Naturales IRN CCMA CSIC | Torre I.,Museu de Granollers Ciencies Naturals | Arrizabalaga A.,Museu de Granollers Ciencies Naturals
Acta Theriologica | Year: 2010

This study aims to quantify the relative effects of density-dependent (feedback structure) and density-independent climatic factors (rainfall) in regulating the short-term population dynamics of wood mice Apodemus sylvaticus Linnaeus, 1758 in three Mediterranean forest plots. Rainfall and density explained additively 62% of variation in population growth rates (38 and 24%, respectively), with no differences among study plots. Population growth rate was positive during autumn-winter and negative during spring summer during a 2.5-year period. Population rate of change was negatively affected by wood mouse density during the normal breeding season of Mediterranean mice (autumn-winter) but not outside it. Growth rate was positively affected by the cumulative amount of rainfall three months before the normal breeding season, but not during it. Female breeding activity and recruitment did not differ among plots, and was not affected by density or rainfall. However, recruitment was positively affected by density and, marginally, by rainfall. Our results suggest that intra specific competition (density dependence) and food availability (rainfall) are equally important factors driving wood mouse population dynamics in Mediterranean forests. Mechanisms underlying density-dependence during the breeding season seemed to be based on food-mediated survival rather than on behaviourally-mediated reproduction. Taken together, these results indicate a high sensitivity of marginal Mediterranean wood mouse populations to the expected climate changes in the Mediterranean region. Source


Torre I.,Museu de Granollers Ciencies Naturals | Arrizabalaga A.,Museu de Granollers Ciencies Naturals | Freixas L.,Museu de Granollers Ciencies Naturals | Ribas A.,University of Antwerp | And 2 more authors.
Basic and Applied Ecology | Year: 2013

Owl pellets have long been used to analyze communities of small mammals, while analogous analyses of faeces of mammal carnivores are not available. We demonstrate that common genet (Genetta genetta) scats can be used as a reliable method to sample small mammal communities and to monitor their variations. We have compiled data on 6350 small mammal remains of 18 species found in scats from 51 different latrines in a 1200km2 area of northeastern Spain. Genet scats sampled effectively 95.6% of the small mammal species ranging in size from 2.7 to 385g. Spatial patterns of diet composition along environmental gradients of elevation, climate and land-use matched expected changes in small mammal communities along these gradients according to ecological requirements of prey species. Frequencies of occurrence of prey in genet scats were strongly correlated with frequencies of occurrence in barn owl (Tyto alba) pellets. Genet scats included two forest species not preyed upon by owls, whereas only one species was not preyed upon by genets. Forests species were more frequent in genet than in barn owl diets after correcting for environmental effects, whereas the opposite was true for open-habitat and synanthropic species. Scats of generalist carnivores can be used to estimate the spatial patterns of distribution and abundance of small mammal communities. Genet scats in fact overcome some of the limitations of more traditional sampling methods (live-trapping and owl diets), as genets were less selective and their diets reflect more accurately changes in community composition. © 2013 Gesellschaft fur Okologie. Source


Devictor V.,French National Center for Scientific Research | Van Swaay C.,Dutch Butterfly Conservation | Brereton T.,Butterfly Conservation | Brotons L.,Catalan Ornithological Institute | And 20 more authors.
Nature Climate Change | Year: 2012

Climate changes have profound effects on the distribution of numerous plant and animal species. However, whether and how different taxonomic groups are able to track climate changes at large spatial scales is still unclear. Here, we measure and compare the climatic debt accumulated by bird and butterfly communities at a European scale over two decades (1990-2008). We quantified the yearly change in community composition in response to climate change for 9,490 bird and 2,130 butterfly communities distributed across Europe. We show that changes in community composition are rapid but different between birds and butterflies and equivalent to a 37 and 114ĝ€‰km northward shift in bird and butterfly communities, respectively. We further found that, during the same period, the northward shift in temperature in Europe was even faster, so that the climatic debts of birds and butterflies correspond to a 212 and 135ĝ€‰km lag behind climate. Our results indicate both that birds and butterflies do not keep up with temperature increase and the accumulation of different climatic debts for these groups at national and continental scales. © 2012 Macmillan Publishers Limited. All rights reserved. Source

Discover hidden collaborations