Search

Adult sex ratios (ASRs) have proved to correlate with population trends, which make them potential useful indicators of a species’ population trajectory and conservation status. We analysed ASRs and proportion of juveniles in flocks of an endangered steppe bird, the Little Bustard Tetrax tetrax, using surveys made during the non-breeding period in seven areas within its Western European range (one in Portugal, four in Spain, and two in France). We found overall male-biased ASRs, as all the seven surveyed areas showed a male-biased ASR mean value. Five areas were below the threshold median value (female sex ratio = 0.4) considered to be consistent with an increased probability of extinction, according to earlier population viability analyses for the species. We also found a significant positive correlation between female ratio and the proportion of young individuals in the non-breeding flocks surveyed. Our results (strongly male-biased ASRs) support the hypothesis that the viability of Little Bustard populations in Western Europe is threatened by an excess of female mortality, something that should be quantified in the future, and emphasise the value of monitoring sex ratio as a population viability indicator in species where monitoring survival is difficult to achieve. This paper is a contribution to the REMEDINAL 3 (S2013/MAE-2719) network which funded a post-doc contract for ESD. It also contributes to the Excellence Network REMEDINAL 3CM (S2013/ MAE2719), supported by Comunidad de Madrid. We thank all the field workers that collaborated in this study. Thanks to Ricardo Montero from Extremadura Birding who provided us with a Little Bustard winter flock video record. We are grateful to Julia Gómez-Catasús for her help with the bootstrapping analysis. This study was carried out with no funds from the Spanish Ministry of Science and Innovation.

Biodiversity has undergone a major decline throughout recent decades, particularly in farmland. Agricultural practices are recognized to be an important pressure on farmland biodiversity, and pesticides are suspected to be one of the main causes of this decline in biodiversity. As part of the national plan for reduction of pesticides use (Ecophyto), the French ministry of agriculture launched the 500 ENI (nonintended effects) monitoring program in 2012 in order to assess the unintended effects of agricultural practices, including pesticide use, on biodiversity represented by several taxonomic groups of interest for farmers. This long‐term program monitors the biodiversity of nontargeted species (earthworms, plants, coleoptera, and birds), together with a wide range of annual data on agricultural practices (crop rotation, soil tillage, weed control, fertilizers, chemical treatments, etc.). Other parameters (e.g., landscape and climatic characteristics) are also integrated as covariates during the analyses. This monitoring program is expected to improve our understanding of the relative contribution of the different drivers of population and community trends. Here, we present the experience of setting up the 500 ENI network for this ambitious and highly complex monitoring program, as well as the type of data it collects. The issue of data quality control and some first results are discussed. With the aim of being useful to readers who would like to set up similar monitoring schemes, we also address some questions that have arisen following the first five years of the implementation phase of the program., We present a national monitoring program on biodiversity and agricultural practices, the 500 ENI monitoring program. Its objectives are to detect changes in biodiversity indicators and simultaneous changes in agricultural practices, including pesticide use. Such multi‐taxa long‐term monitoring at national scale, focused on both biodiversity and agricultural practices, has no equivalent in Europe.

Pour évaluer les effets non intentionnels des pratiques agricoles sur la biodiversité, un réseau de 500 parcelles (réseau Biovigilance 500 ENI) a été mis en place en France métropolitaine par les pouvoirs publics. Quatre taxons sont suivis depuis 2012 : les vers de terre, la flore des bordures de champs, les coléoptères et les oiseaux. Nous présentons ici des résultats préliminaires et descriptifs pour la faune et une analyse plus détaillée de la réponse de la flore aux variables environnementales et agricoles. Des approches multivariées et des modèles additifs généralisés mixtes ont été utilisés pour tester les liens entre la nature et la diversité des traits de 186 espèces végétales et 12 variables environnementales et agricoles. Outre un effet de la diversité du paysage, de la fréquence de gestion et de la largeur des bordures, la quantité d’engrais azotés apportés dans la parcelle a un effet sur la composition de la flore des bordures en favorisant les espèces les plus nitrophiles. La richesse en espèces et leur diversité fonctionnelle diminuent avec l’indice de fréquence de traitements (IFT) herbicides et avec la surface de la parcelle. Les premiers résultats obtenus sont cohérents et montrent la valeur des données récoltées par les observateurs du réseau Biovigilance 500 ENI pour identifier les effets non-intentionnels des pratiques sur la biodiversité., To assess the unintended effects of agricultural practices on biodiversity, a network of 500 plots (Biovigilance 500 ENI network) was set up in metropolitan France by the public authorities. Four taxa have been monitored since 2012: earthworms, flora of field margins, beetles and birds. Here we present[br/] preliminary and descriptive results for wildlife and a more detailed analysis of the response of flora to environmental and agricultural variables. Multivariate approaches and generalized additive mixed models were used to test the links between the nature and diversity of 186 plant species traits and 12 environmental and agricultural variables. In addition to an effect of landscape diversity, field margin management frequency and field margin width, the amount of nitrogen fertilizer applied within the field has an effect on the composition of the flora of field margin favoring the most nitrophilous species. Species richness and functional diversity decrease with the Treatment Frequency Index (IFT) of herbicides and with the field area. The first results obtained are consistent and show the value of the data collected by observers of the Biovigilance 500 ENI network to identify unintended effects of farming practices on biodiversity.

National audience; To assess the unintended effects of agricultural practices on biodiversity, a network of 500 plots (Biovigilance 500 ENI network) was set up in metropolitan France by the public authorities. Four taxa have been monitored since 2012: earthworms, flora of field margins, beetles and birds. Here we present preliminary and descriptive results for wildlife and a more detailed analysis of the response of flora to environmental and agricultural variables. Multivariate approaches and generalized additive mixed models were used to test the links between the nature and diversity of 186 plant species traits and 12 environmental and agricultural variables. In addition to an effect of landscape diversity, field margin management frequency and field margin width, the amount of nitrogen fertilizer applied within the field has an effect on the composition of the flora of field margin favoring the most nitrophilous species. Species richness and functional diversity decrease with the Treatment Frequency Index (IFT) of herbicides and with the field area. The first results obtained are consistent and show the value of the data collected by observers of the Biovigilance 500 ENI network to identify unintended effects of farming practices on biodiversity.; Pour évaluer les effets non intentionnels des pratiques agricoles sur la biodiversité, un réseau de 500 parcelles (réseau Biovigilance 500 ENI) a été mis en place en France métropolitaine par les pouvoirs publics. Quatre taxons sont suivis depuis 2012 : les vers de terre, la flore des bordures de champs, les coléoptères et les oiseaux. Nous présentons ici des résultats préliminaires et descriptifs pour la faune et une analyse plus détaillée de la réponse de la flore aux variables environnementales et agricoles. Des approches multivariées et des modèles additifs généralisés mixtes ont été utilisés pour tester les liens entre la nature et la diversité des traits de 186 espèces végétales et 12 variables environnementales et agricoles. Outre un effet de la diversité du paysage, de la fréquence de gestion et de la largeur des bordures, la quantité d’engrais azotés apportés dans la parcelle a un effet sur la composition de la flore des bordures en favorisant les espèces les plus nitrophiles. La richesse en espèces et leur diversité fonctionnelle diminuent avec l’indice de fréquence de traitements (IFT) herbicides et avec la surface de la parcelle. Les premiers résultats obtenus sont cohérents et montrent la valeur des données récoltées par les observateurs du réseau Biovigilance 500 ENI pour identifier les effets non-intentionnels des pratiques sur la biodiversité.

International audience

A circannual perspective on daily and total flight distances in a long-distance migratory raptor, the Montagu's harrier Circus pygargus

International audience; The Little Bustard has undergone a steep reduction of its Western Palaearctic range over the last century. In the west of France, breeding populations declined by 96% from 1978 to 2008 in cultivated areas where grasslands have been converted into intensively managed annual crops. Little Bustard abundance and nest productivity have been monitored since 1995 in a 450-km2 site in western France. We assessed the proximate causes of the decline of Little Bustards in French farming landscapes and quantified the effectiveness of conservation measures that aimed to reverse the decline. The decline of Little Bustard, from about 65 males in 1995 to just six males in 2003, could be related to a near absence of recruitment over this period. Since 2004, the establishment of more than 1300 ha of specifically targeted agri-environment schemes (AES) in the study site has led to a sharp increase in female productivity, mainly associated with nesting in AES fields. By imposing constraints on mowing dates, AES have prevented nest destruction and female mortality during mowing and, by increasing plant species diversity, provided chicks with a higher abundance of grasshoppers. This has contributed to reversing the trend, and increasing the population to around 30 males in 2009. Conservation strategies involving specifically targeted AES based on the identification of limiting factors can help to reverse the decline of threatened species.