439 research outputs found
Bimodal breeding phenology in the Parsley Frog <i>Pelodytes punctatus</i> as a bet-hedging strategy in an unpredictable environment despite strong priority effects
BIRDS AND SUSTAINABLE MANAGEMENT IN MEDITERRANEAN RIPARIAN AREAS: Bird studies in the RIPIDURABLE project
RIPIDURABLE is an INTERREG IIIC European Program involving 10 partners from Portugal, Spain, France and Greece. Scientists, technicians and local/regional authorities worked together to integrate knowledge, knowhow and practice, towards a rational conservation management of riparian zones. Birds can be used to characterize ecosystems, to monitor environmental changes or to assess results of restoration measures. We have conducted field surveys in order to assess breeding bird communities associated to riparian galleries in several
watercourses, including issues as the relation with natural vegetation profiles, the influence of the surrounding
matrix, the evolution with time or with habitat degradation, the effects of rehabilitation measures, and/or the
importance of riparian galleries as ecological corridors for birds. Surveys at different space and time scales were
carried out using standardised point count methods, on 8 watercourses in Portugal and France. We focused on different aspects of riparian breeding bird community variation: along a decreasing gradient of vegetal
complexity (Tagus Basin), along an upstream-downstream gradient (Allier), with different surrounding landscapes (Sado, Guadiana and Tagus Basin), with time (Alcáçovas at a 10 years interval, Allier at 16 years
interval), with management status (Vidourle), with time & management status (Rhône delta at a 12 years intervals), before & after river rehabilitation (Gandum). In addition we studied the dispersal of Barn Owls from upper Tagus Estuary along riparian corridors (TytoTagus Project), and also the importance of riparian habitats of the Guadiana basin on the autumn migration of trans-Saharan birds across the Iberian Peninsula. The RIPIDURABLE project offered the opportunity for further research currently included in national programs such as the Plan Loire Grandeur Nature which allows long term studies on riparian birds. Herein we briefly present some of the preliminary results of the bird studies carried out by partners from Portugal and France
Increased birth rank of homosexual males: disentangling the older brother effect and sexual antagonism hypothesis
Male homosexual orientation remains a Darwinian paradox, as there is no consensus on its evolutionary (ultimate) determinants. One intriguing feature of homosexual men is their higher male birth rank compared to heterosexual men. This can be explained by two non-exclusive mechanisms: an antagonistic effect (AE), implying that more fertile women have a higher chance of having a homosexual son and to produce children with a higher mean birth rank, or a fraternal birth effect (FBOE), where each additional older brother increases the chances for a male embryo to develop a homosexual orientation due to an immunoreactivity process. However, there is no consensus on whether both FBOE and AE are present in human populations, or if only one of these mechanisms is at play with its effect mimicking the signature of the other mechanism. An additional sororal birth order effect (SBOE) has also recently been proposed. To clarify this situation, we developed theoretical and statistical tools to study FBOE and AE independently or in combination, taking into account all known sampling biases. These tools were applied on new individual data, and on various available published data (two individual datasets, and all relevant aggregated data). Support for FBOE was apparent in aggregated data, with the FBOE increasing linearly with fertility. The FBOE was also supported in two individual datasets. An SBOE is generated when sampling in presence of FBOE, suggesting that controlling for FBOE is required to avoid artefactual SBOE. AE was not supported in individual datasets, including the analysis of the extended maternal family. The evolutionary implications of these findings are discussed
Phylogeographic breaks and how to find them: An empirical attempt at separating vicariance from isolation by distance in a lizard with restricted dispersal
Conservation Biogeography of the Sahara‐Sahel: additional protected areas are needed to secure unique biodiversity
Aim Identification of priority conservation areas and evaluation of coverage of
the current protected areas are urgently needed to halt the biodiversity loss.
Identifying regions combining similar environmental traits (climate regions)
and species assemblages (biogroups) is needed for conserving the biodiversity
patterns and processes. We identify climate regions and biogroups and map
species diversity across the Sahara-Sahel, a large geographical area that exhibits
wide environmental heterogeneity and multiple species groups with distinct
biogeographical affinities, and evaluate the coverage level of current network of
protected areas for biodiversity conservation.
Location Sahara-Sahel, Africa.
Methods We use spatially explicit climate data with the principal component
analysis and model-based clustering techniques to identify climate regions.
We use distributions of 1147 terrestrial vertebrates (and of 125 Sahara-Sahel
endemics) and apply distance clustering methods to identify biogroups for
both species groups. We apply reserve selection algorithms targeting 17% of
species distribution, climate regions and biogroups to identify priority areas
and gap analysis to assess their representation within the current protected
areas.
Results Seven climate regions were identified, mostly arranged as latitudinal
belts. Concentrations of high species richness were found in the Sahel, but the
central Sahara gathers most endemic and threatened species. Ten biogroups
(five for endemics) were identified. A wide range of biogroups tend to overlap
in specific climate regions. Identified priority areas are inadequately represented
in protected areas, and six new top conservation areas are needed to achieve
conservation targets.
Main conclusions Biodiversity distribution in Sahara-Sahel is spatially structured and apparently related to environmental variation. Although the majority of priority conservation areas are located outside the areas of intense
human activities, many cross multiple political borders and require internationally coordinated efforts for implementation and management. Optimized
biodiversity conservation solutions at regional scale are needed. Our work
contradicts the general idea that deserts are uniform areas and provide
options for the conservation of endangered species.info:eu-repo/semantics/publishedVersio
Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV
Peer reviewe
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