Mixed effects of long-term conservation investment in Natura 2000 farmland

Evaluating the effectiveness of conservation funding is crucial for correct allocation of limited resources. Here we used bird monitoring data to assess the effects of long-term conservation investment in a Natura 2000 (N2000) bird protection area (PA), which during two decades benefited from protection regulations, conservation projects, and agri-environment schemes. Variation between 1995–1997 and 2010–2012 in richness and abundance of flagship (Otis tarda, Tetrax tetrax, and Falco naumanni) and specialized fallow field species were more favorable (i.e., increased more or declined less) inside the PA than in a nearby control area. However, the reverse was found for total bird species, farmland, ground-nesting and steppe species, species associated to ploughed fields, and species of European conservation concern. Enhancing the effectiveness of conservation investment in N2000 farmland may require a greater focus on the wider biodiversity alongside that currently devoted to flagship species, as well as improved matching between conservation and agricultural policies.info:eu-repo/semantics/publishedVersio

Toward a loss of functional diversity in stream fish assemblages under climate change

The assessment of climate change impacts on biodiversity has so far been biased toward the taxonomic identification of the species likely either to benefit from climate modifications or to experience overall declines. There have still been few studies intended to correlate the characteristics of species to their sensitivity to climate change, even though it is now recognized that functional trait-based approaches are promising tools for addressing challenges related to global changes. In this study, two functional indices (originality and uniqueness) were first measured for 35 fish species occurring in French streams. They were then combined to projections of range shifts in response to climate change derived from species distribution models. We set out to investigate: (1) the relationship between the degrees of originality and uniqueness of fish species, and their projected response to future climate change; and (2) the consequences of individual responses of species for the functional diversity of fish assemblages. After accounting for phylogenetic relatedness among species, we have demonstrated that the two indices used measure two complementary facets of the position of fish species in a functional space. We have also rejected the hypothesis that the most original and/or less redundant species would necessarily experience the greatest declines in habitat suitability as a result of climate change. However, individual species range shifts could lead simultaneously both to a severe decline in the functional diversity of fish assemblages, and to an increase in the functional similarity among assemblages, supporting the hypothesis that disturbance favors communities with combination of common traits and biotic homogenization as well. Our findings therefore emphasize the importance of going beyond the simple taxonomic description of diversity to provide a better assessment of the likely future effects of environmental changes on biodiversity, thus helping to design more effective conservation and management measures

Coexistence of two sympatric cryptic bat species in French Guiana: insights from genetic, acoustic and ecological data

International audienceBackground: The distinction between lineages of neotropical bats from the Pteronotus parnellii species complex has been previously made according to mitochondrial DNA, and especially morphology and acoustics, in order to separate them into two species. In these studies, either sample sizes were too low when genetic and acoustic or morphological data were gathered on the same individuals, or genetic and other data were collected on different individuals. In this study, we intensively sampled bats in 4 caves and combined all approaches in order to analyse genetic, morphologic, and acoustic divergence between these lineages that live in the same caves in French Guiana

Local factors mediate the response of biodiversity to land use on two African mountains

Land-use change is the single biggest driver of biodiversity loss in the tropics. Biodiversity models can be useful tools to inform policymakers and conservationists of the likely response of species to anthropogenic pressures, including land-use change. However, such models generalize biodiversity responses across wide areas and many taxa, potentially missing important characteristics of particular sites or clades. Comparisons of biodiversity models with independently collected field data can help us understand the local factors that mediate broad-scale responses. We collected independent bird occurrence and abundance data along two elevational transects in Mount Kilimanjaro, Tanzania and the Taita Hills, Kenya. We estimated the local response to land use and compared our estimates with modelled local responses based on a large database of many different taxa across Africa. To identify the local factors mediating responses to land use, we compared environmental and species assemblage information between sites in the independent and African-wide datasets. Bird species richness and abundance responses to land use in the independent data followed similar trends as suggested by the African-wide biodiversity model, however the land-use classification was too coarse to capture fully the variability introduced by local agricultural management practices. A comparison of assemblage characteristics showed that the sites on Kilimanjaro and the Taita Hills had higher proportions of forest specialists in croplands compared to the Africa-wide average. Local human population density, forest cover and vegetation greenness also differed significantly between the independent and Africa-wide datasets. Biodiversity models including those variables performed better, particularly in croplands, but still could not accurately predict the magnitude of local species responses to most land uses, probably because local features of the land management are still missed. Overall, our study demonstrates that local factors mediate biodiversity responses to land use and cautions against applying biodiversity models to local contexts without prior knowledge of which factors are locally relevant

A Holistic Landscape Description Reveals That Landscape Configuration Changes More over Time than Composition: Implications for Landscape Ecology Studies

International audienceBackground: Space-for-time substitution—that is, the assumption that spatial variations of a system can explain and predict the effect of temporal variations—is widely used in ecology. However, it is questionable whether it can validly be used to explain changes in biodiversity over time in response to land-cover changes.Hypothesis: ere, we hypothesize that different temporal vs spatial trajectories of landscape composition and configuration may limit space-for-time substitution in landscape ecology. Land-cover conversion changes not just the surface areas given over to particular types of land cover, but also affects isolation, patch size and heterogeneity. This means that a small change in land cover over time may have only minor repercussions on landscape composition but potentially major consequences for landscape configuration.Methods: sing land-cover maps of the Paris region for 1982 and 2003, we made a holistic description of the landscape disentangling landscape composition from configuration. After controlling for spatial variations, we analyzed and compared the amplitudes of changes in landscape composition and configuration over time.Results: For comparable spatial variations, landscape configuration varied more than twice as much as composition over time. Temporal changes in composition and configuration were not always spatially matched.Significance: The fact that landscape composition and configuration do not vary equally in space and time calls into question the use of space-for-time substitution in landscape ecology studies. The instability of landscapes over time appears to be attributable to configurational changes in the main. This may go some way to explaining why the landscape variables that account for changes over time in biodiversity are not the same ones that account for the spatial distribution of biodiversity

Impact des pratiques agricoles et de l urbanisation sur les communautés d oiseaux agricoles

L agriculture moderne a causé le déclin de nombreuses espèces d oiseaux, ce qui a amené les hommes à se préoccuper d avantage de leur protection. Cette thèse s inscrit dans cette démarche et vise à étudier les impacts différentiels de plusieurs menaces sur les espèces d oiseaux agricoles. Je m intéresse d abord aux menaces anthropiques pesant sur ces espèces via l impact de leur degré de spécialisation sur leur sensibilité à être influencées par l intensité des pratiques agricoles, de la simplification paysagère et de l urbanisation. Un résultat commun à ces deux recherches est la structuration différente des communautés selon ces intensités. Une troisième étude portera sur l impact de l urbanisation sur la diversité fonctionnelle des communautés d oiseaux via l utilisation de trois indices proposés dans la bibliographie. Dans une deuxième partie, je m interroge sur l efficacité de l agriculture biologique et du labour superficiel quant à la protection des espèces spécialistes. Enfin, je recherche s il y a des différences de perception de la biodiversité et des programmes agri-environnementaux.par les agriculteurs.PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF

Athérothrombose coronaire et régulation génétique (influence du polymorphisme génétique 4G/5G de la région promotrice du gène de PAI-1 sur la morbimortalité après infarctus du myocarde)

CAEN-BU Médecine pharmacie (141182102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Effects of non-cropped landscape diversity on spatial dynamics of farmland birds in intensive farming systems

International audienceIncreasing habitats diversity in agricultural landscapes has been proposed as a key measure for reversingthe decline of farmland biodiversity in Europe. However, indicators used for assessing such a potentialcompensation effect usually only rely on species diversity and abundance while ignoring variations inspecies-specific vulnerability. The extent to which habitat diversity may reverse the decline of specialistspecies in Europe to farming systems is thus still unclear. In this study, we investigate whether the effectof non-cropped habitat diversity on farmland birds’ occurrences was dependent on species’ specializationfor habitats. In particular, we focused on the relative effects of non-cropped habitat diversity on species’abilities to persist or to colonize new vacant areas. We used a capture–recapture statistical framework tostudy the spatial dynamics of 20 farmland bird species in France monitored from 2001 to 2007. We foundthat non-cropped landscape diversity reduces both the probabilities that a species becomes extinctlocally and that a species colonizes new vacant areas, and the occupancy rate. Although this suggests apossible stabilizing effect of the surrounding habitat diversity on species occurrence in farming systems,the occupancy was only weakly affected. Moreover, we found that the most specialist species were themore negatively affected by this landscape diversity in terms of colonization abilities. We argue thataccounting for the differences in habitat specialization among farmland species can improve conservationpolicies dedicated to the management of landscape diversity

Active territory defence at a low energy cost in a colonial seabird

International audienceAggressive behaviour associated with the defence of a territory is thought to impose substantial energy costs and thus to represent a trade-off with other energy-demanding activities. The energy costs of aggressive behaviours, however, have rarely been estimated in the wild, and the overall contribution of territorial defence to daily energy expenditure has never been determined. We studied the activity budget of breeding king penguins, Aptenodytes patagonicus, equipped with heart rate data loggers to estimate the energy costs associated with territory defence in this colonial bird exhibiting very high rates of agonistic interactions. We also assessed whether threat displays imposed lower energy costs than attacks with body contact. During territorial defence (i.e. threats and physical attacks combined), energy expenditure averaged 1.27 times resting metabolic rate. Defence accounted for 13% of the daily time budget and contributed to 2.7% of the total daily energy expenditure. Interactions with body contact cost three times more than threat displays, but accounted for only 16% of the aggressive behaviours recorded. Neither did body mass, body size, penguin sex or breeding stage affect the cost of aggressiveness. Our results are consistent with previous research reporting that fighting imposes significant metabolic costs. However, we found that aggressive behaviour in king penguins was not an expensive activity compared to the total energy budget. Because king penguins go without food and are sleep deprived while breeding, they may have developed behavioural strategies (e.g. lower rates of attacks with body contact) allowing them to defend their territory efficiently at a low energy cos