Restauration hydraulique d'un marais et conséquences pour les oiseaux : contraintes d'échelles d'espace et de temps dans les processus écologiques

Over the last thirty years the intensification of agricultural practices by drainage and conversion of grass lands to arable has led to the loss of hydrological and ecological functions of wetlands in the western marshes of France, in particular the conservation of animais characteristic of these wetlands. The goal of this study was to res tore at !east sorne of the ecological functions of wet grasslands by experimentally manipulating the water regime and grazing; the consequences for the plant and bird communities were measured. This was done in an experimental set-up of 63 fields covering 170 ha in the Marais de Brouage (Charente-Maritime). The water regime is driven by natural processes (rainfall and evaporation) and artificially, through the manipulation of the leve! of the main canal. By modifying the subsidiary canals and building sluice gates it was possible to isolate experimental fields from the influence of the main canal. The experimental fields were subjected to two treatments, dry (minimal flooding), intermediate (six months flooding) and wet (10 months). We worked at three hierarchical spatial levels, a field, a single catchment area and a set of catchment areas. For the restoration of biodiversity in this case particular bird species, we underline the importance of choosing the appropriate spatial level, which will depend on the objectives. In this welland system, which reacts fast, the time scale is not a major constraint. Particular attention was paid to birds because these are known to be good indicators of other animal groups, and because the changes in agricultural practices have led to declines in most of the species of farmland in Europe. Between 1997-2001 we counted breeding birds (principally the Skylark A lauda arvensis and the Yellow wagtail Motacilla jlava ). The former species declined and the latter increased in the set of catchment areas (170 ha). We tested the hypothesis that this was due to an increase in the duration of flooding : at the field level, the Skylark declined and Wagtails increased when the duration of flooding increased. It is therefore possible to experimentally induce rapid changes in the populations of the se birds at small spatial scales. In contrast for other species such as the breeding waders, and in particular the Lapwing Vanellus vanellus, no response was obtained at the se spatial and temporal scales. However, at the scale of the whole marsh (12000 ha) and 12 years major changes occurred in the ahundance and distribution of Lapwings, many of the birds moving from wet grasslands to arable for nesting. We propose hypotheses to explain this which require testing in the future. These results show the importance of choosing clear objectives in ecological restoration projects, and appropriate indicator species. Since the ecological processes involved occur at different spatial and temporal scales, the level of biological organisation selected and the species will modulate the expression of the processesDepuis une trentaine d'années, l'intensification de l'agriculture par le drainage et la mise en culture a entraîné la perte des fonctions hydrauliques et écologiques des marais de la façade atlantique. Conservation et réhabilitation de la biodiversité de ces milieux sont à l'origine de notre étude. Grâce à un dispositif expérimental de terrain (63 parcelles, 170 ha) situé dans le marais de Brouage (Charente-Maritime), nous avons cherché à restaurer le caractère humide des prairies naturelles en manipulant la gestion hydraulique et pastorale, et en mesurant les conséquences sur les oiseaux. Les parcelles en prairie ont été soumises à trois « scénarios » de gestion hydraulique : le scénario « sec » (durée d'inondation minimale), le scénario « intermédiaire » (inondation d'environ 6 mois) et le scénario « humide » (inondation d'environ 10 mois). Entre 1997 et 2001, des dénombrements exhaustifs des passereaux nicheurs (Alouette des champs Alauda arvensis et Bergeronnette printanière Motacilla flava), ont montré qu'à une échelle temporelle de cinq ans, il est possible d'enregistrer des évolutions d'abondance des populations (baisse de la densité des alouettes et augmentation de celle des bergeronnettes) en fonction du degré d'humidité dans la parcelle. Par ailleurs, le suivi de la dynamique des populations du Vanneau huppé (Vanellus vanellus) a montré que l'échelle spatiale choisie (170 ha) n'était pas adaptée et qu'il fallait prendre en compte l'ensemble du marais, soit 12000 hectares. Sur le plan temporel, des changements très significatifs dans 1'utilisation de 1'espace sont intervenus chez cette espèce, mais ces changements n'auraient pu être détectés en 3 années seulemen

Activities and food resources of wintering Teal (Anas crecca) in a diurnal feeding site : a case study in western France

In winter, dabbling ducks generally use a set of two distinct habitats over the 24-hour cycle, resting in large groups on a few large waterbodies during daylight hours, and dispersing at night into many smaller feeding habitats. In sorne circumstances, birds use the same site during both daylight hours and during the night. This study was conducted on a small (< 1 ha) pond used by Teal (Anas crecca) by day and by night in the early part of the winter. Duck numbers were not related either to the abundance of food resources, water levels or pond area. Teal had the same pattern of behaviour during daylight and at night, foraging being the main activity through the whole period of their presence on the site. Comfort activities decreased with increasing water levels and pond area, perhaps because the predation risk is greater in these conditions. This study contributes to understanding the factors affecting the use of diurnal feeding sites by TealEn hiver, les canards de surface utilisent en général deux types d'habitats distincts au cours des 24 heures, les oiseaux se reposant en grand nombre la journée sur quelques plans d'eau de grande taille, et se dispersant la nuit pour s'alimenter sur de nombreuses zones plus petites. Dans certains cas, les canards peuvent toutefois utiliser le même plan d'eau le jour et la nuit. Cette étude a été menée sur un plan d'eau de moins d'un hectare, utilisé par des Sarcelles d'hiver (Anas crecca) à la fois le jour et la nuit au début de l'hiver. Le nombre de canards n'était pas lié à l'abondance des ressources alimentaires, aux niveaux d'eau ou à la surface du bassin. Leur budget-temps n'était pas différent entre le jour et la nuit, l'alimentation étant toujours l'activité principale. L'importance des activités de confort a décliné avec l'augmentation des niveaux d'eau et de la surface du bassin, qui a pu augmenter le risque de prédation potentielle. Cette étude permet de mieux comprendre les facteurs régissant l'utilisation de zones d'alimentation diurnes par les sarcelles d'hive

Hygroregulation, a key ability for eusocial insects: Native Western European honeybees as a case study

Sociality has brought many advantages to various hymenoptera species, including their ability of regulating physical factors in their nest (e.g., temperature). Although less studied, humidity is known to be important for egg, larval and pupal development, and also for nectar concentration. Two subspecies of Apis mellifera of the M evolutionary lineage were used as models to test the ability of a superorganism (i.e. honeybee colony) to regulate the humidity in its nest (i.e. “hygroregulation hypothesis”) in four conservation centers: two in France (A. m. mellifera) and two in Portugal (A. m. iberiensis). We investigated the ability of both subspecies to regulate the humidity in hives daily, but also during the seasons for one complete year. Our data and statistical analysis demonstrated the capacity of the bees to regulate humidity in their hive, regardless of the day, season or subspecies. Furthermore, the study showed that humidity in beehives is stable even during winter, when brood is absent, and when temperature is known to be less stable in the beehives. These results suggest that humidity is important for honeybees at every life stage, maybe because of the ‘imprint’ of the evolutionary history of this hymenopteran lineage.This work was supported in part by the research project BEEHOPE funded by the European call for projects 2013-2014 BiodivERsA / FACCEJPI from research agencies of France (ANR-14- EBID-0001), Spain (PCIN-2014-090) and Portugal (BiodivERsA /0002/2014). I. Eouzan is financed by a doctoral grant from the Ministry of National Education, Higher Education and Research (France).info:eu-repo/semantics/publishedVersio

BEEHOPE: um projeto de conservação das subespécies nativas de abelha da Europa Ocidental (linhagem M) à escala Europeia

O projeto BEEHOPE, com o título original “Honeybee conservation centres in western Europe - an innovative strategy using sustainable beekeeping to reduce honeybee decline”, foi um dos 10 aprovados na área da biodiversidade do 5º concurso transnacional (2013-2014) BiodivErsA/FACCE-JPI (http://www.biodiversa.org/766), subordinado ao tema “Promover sinergias e reduzir o compromisso entre o abastecimento de alimentos, biodiversidade e serviços dos ecossistemas”. A diversidade nativa das populações de abelha melífera (Apis mellifera) da linhagem da Europa ocidental (M) tem vindo a ser crescentemente ameaçada pela introdução massiva de colónias da linhagem da Europa oriental (C, onde se incluem as subespécies A. m. ligustica, A. m. carnica, A. m. macedónica etc.), e também por outros fatores bióticos (Varroa e vírus associados, Nosema etc.) e abióticos (pesticidas, perda e fragmentação de habitat, alterações climáticas etc.). É neste contexto que surge o projeto BEEHOPE, o qual tem por objetivo último contribuir para a conservação da diversidade genética das populações de abelha melífera da linhagem M.info:eu-repo/semantics/publishedVersio

Activities and food resources of wintering Teal (Anas crecca) in a diurnal feeding site : a case study in western France

In winter, dabbling ducks generally use a set of two distinct habitats over the 24-hour cycle, resting in large groups on a few large waterbodies during daylight hours, and dispersing at night into many smaller feeding habitats. In some circumstances, birds use the same site during both daylight hours and during the night. This study was conducted on a small (< 1 ha) pond used by Teal (Anas crecca) by day and by night in the early part of the winter. Duck numbers were not related either to the abundance of food resources, water levels or pond area Teal had the same pattern of behaviour during daylight and at night, foraging being the main activity through the whole period of their presence on the site. Comfort activities decreased with increasing water levels and pond area, perhaps because the predation risk is greater in these conditions. This study contributes to understanding the factors affecting the use of diurnal feeding sites by Teal.En hiver, les canards de surface utilisent en général deux types d’habitats distincts au cours des 24 heures, les oiseaux se reposant en grand nombre la journée sur quelques plans d’eau de grande taille, et se dispersant la nuit pour s’alimenter sur de nombreuses zones plus petites. Dans certains cas, les canards peuvent toutefois utiliser le même plan d’eau le jour et la nuit. Cette étude a été menée sur un plan d’eau de moins d’un hectare, utilisé par des Sarcelles d’hiver (Anas crecca) à la fois le jour et la nuit au début de l’hiver. Le nombre de canards n’était pas lié à l’abondance des ressources alimentaires, aux niveaux d’eau ou à la surface du bassin. Leur budget-temps n’était pas différent entre le jour et la nuit, l’alimentation étant toujours l’activité principale. L’importance des activités de confort a décliné avec l’augmentation des niveaux d’eau et de la surface du bassin, qui a pu augmenter le risque de prédation potentielle. Cette étude permet de mieux comprendre les facteurs régissant l’utilisation de zones d’alimentation diurnes par les sarcelles d’hiver.Guillemain Matthieu, Houte Sylvie, Fritz Hervé. Activities and food resources of wintering Teal (Anas crecca) in a diurnal feeding site : a case study in western France. In: Revue d'Écologie (La Terre et La Vie), tome 55, n°2, 2000. pp. 171-181

Restauration hydraulique d’un marais et conséquences pour les oiseaux : contraintes d’échelles d’espace et de temps dans les processus écologiques

Over the last thirty years the intensification of agricultural practices by drainage and conversion of grasslands to arable has led to the loss of hydrological and ecological functions of wetlands in the western marshes of France, in particular the conservation of animals characteristic of these wetlands. The goal of this study was to restore at least some of the ecological functions of wet grasslands by experimentally manipulating the water regime and grazing ; the consequences for the plant and bird communities were measured. This was done in an experimental set-up of 63 fields covering 170 ha in the Marais de Brouage (Charente-Maritime). The water regime is driven by natural processes (rainfall and evaporation) and artificially, through the manipulation of the level of the main canal. By modifying the subsidiary canals and building sluice gates it was possible to isolate experimental fields from the influence of the main canal. The experimental fields were subjected to two treatments, dry (minimal flooding), intermediate (six months flooding) and wet (10 months). We worked at three hierarchical spatial levels, a field, a single catchment area and a set of catchment areas. For the restoration of biodiversity in this case particular bird species, we underline the importance of choosing the appropriate spatial level, which will depend on the objectives. In this wetland system, which reacts fast, the time scale is not a major constraint. Particular attention was paid to birds because these are known to be good indicators of other animal groups, and because the changes in agricultural practices have led to declines in most of the species of farmland in Europe. Between 1997-2001 we counted breeding birds (principally the Skylark Alauda arvensis and the Yellow wagtail Motacilla flava). The former species declined and the latter increased in the set of catchment areas (170 ha). We tested the hypothesis that this was due to an increase in the duration of flooding : at the field level, the Skylark declined and Wagtails increased when the duration of flooding increased. It is therefore possible to experimentally induce rapid changes in the populations of these birds at small spatial scales. In contrast for other species such as the breeding waders, and in particular the Lapwing Vanellus vanellus, no response was obtained at these spatial and temporal scales. However, at the scale of the whole marsh (12 000 ha) and 12 years major changes occurred in the abundance and distribution of Lapwings, many of the birds moving from wet grasslands to arable for nesting. We propose hypotheses to explain this which require testing in the future. These results show the importance of choosing clear objectives in ecological restoration projects, and appropriate indicator species. Since the ecological processes involved occur at different spatial and temporal scales, the level of biological organisation selected and the species will modulate the expression of the processes.Depuis une trentaine d’années, l’intensification de l’agriculture par le drainage et la mise en culture a entraîné la perte des fonctions hydrauliques et écologiques des marais de la façade atlantique. Conservation et réhabilitation de la biodiversité de ces milieux sont à l’origine de notre étude. Grâce à un dispositif expérimental de terrain (63 parcelles, 170 ha) situé dans le marais de Brouage (Charente-Maritime), nous avons cherché à restaurer le caractère humide des prairies naturelles en manipulant la gestion hydraulique et pastorale, et en mesurant les conséquences sur les oiseaux. Les parcelles en prairie ont été soumises à trois «scénarios » de gestion hydraulique : le scénario «sec» (durée d’inondation minimale), le scénario «intermédiaire» (inondation d’environ 6 mois) et le scénario «humide» (inondation d’environ 10 mois). Entre 1997 et 2001, des dénombrements exhaustifs des passereaux nicheurs (Alouette des champs Alauda arvensis et Bergeronnette printanière Motacilla flava), ont montré qu’à une échelle temporelle de cinq ans, il est possible d’enregistrer des évolutions d’abondance des populations (baisse de la densité des alouettes et augmentation de celle des bergeronnettes) en fonction du degré d’humidité dans la parcelle. Par ailleurs, le suivi de la dynamique des populations du Vanneau huppé (Vanellus vanellus) a montré que l’échelle spatiale choisie (170 ha) n’était pas adaptée et qu’il fallait prendre en compte l’ensemble du marais, soit 12 000 hectares. Sur le plan temporel, des changements très significatifs dans l’utilisation de l’espace sont intervenus chez cette espèce, mais ces changements n’auraient pu être détectés en 3 années seulement.Bretagnolle Vincent, Houte Sylvie, Boileau Nicolas. Restauration hydraulique d’un marais et conséquences pour les oiseaux : contraintes d’échelles d’espace et de temps dans les processus écologiques . In: Revue d'Écologie. Supplément n°9, 2002. pp. 175-187

Distribution maps and minimum abundance estimates for wintering auks in the Bay of Biscay, based on aerial surveys

The “Erika” oil spill has killed more seabirds than any before in Europe: nearly 70 000 guillemots (Uria aalge) were found dead or alive on beaches, and many more are thought to have been killed. This unexpectedly high number highlighted how poor our knowledge was on spatial and temporal patterns in seabird distribution in the Bay of Biscay. The purpose of our research project, “ERIKA-Avion”, was to fill this gap, providing the first distribution maps and abundance estimates of seabirds wintering in the entire shelf of the Bay of Biscay. In particular, we analysed fine-grained distribution maps for the wintering auks, comparing their areas of highest density with the oil drift area, and proposing for the first time (although preliminarily) minimal abundance estimates for these birds in this area

L’éducation relative à l’environnement pour stimuler différents niveaux d’engagement environnemental : le cas du dispositif Mon Village Espace de Biodiversité

La place accordée à l’action citoyenne dans l’espace public n’a cessé de croître depuis le XXe siècle, sans que les conséquences de telles initiatives ne soient toujours analysées. Cet article explore comment un dispositif encourageant des initiatives citoyennes pour la biodiversité, qui s’appuie sur une démarche scientifique, peut favoriser l’implication d’adultes. Il repose sur l’exemple du dispositif d’éducation à l’environnement Mon Village Espace de Biodiversité (France). Proposé aux habitants de la Zone Atelier Plaine et Val de Sèvre, ce dispositif offre une grande diversité d’entrées possibles dans l’action environnementale et à plusieurs échelles : accueillir et observer un abri à insectes dans son jardin (échelle individuelle) ; participer à la gestion d’un rucher public (échelle communale) ; rejoindre un groupe de citoyens porteurs de projets de conservation de la biodiversité (échelle du territoire). Des enquêtes qualitatives et quantitatives et un atelier d’évaluation menés en 2016 montrent que ces opportunités de contact avec la nature peuvent favoriser les actions pro-environnementales dans la sphère privée ; accroître la connaissance et l’affinité pour la nature des participants ; développer le lien social dans les communes ; promouvoir l’empowerment des volontaires et la création de collectifs.The 20th century has been marked by a larger space left for citizen participation in the public arena. However, the impact of these initiatives remains to be investigated. This article explores the way a science-based program promoting citizen initiatives for biodiversity can encourage adults’ involvement. It is based on the example of an environmental education program launched in the Long Term Ecological Research platform (LTSER) Plaine et Val de Sèvre area (France) : Mon Village Espace de Biodiversité. Various levels of environmental action are proposed to inhabitants through this program. The installation and the observation of a wooden insect shelter in private gardens (individual level) ; the participation to the management of a public apiary (communal level) ; the involvement in a group of citizens leading projects for biodiversity protection (territory level). In 2016, we explored the consequences of such participations though qualitative and quantitative studies, as well as through an evaluation workshop. Our results showed that these initiatives provide opportunities to be in contact with nature, which can promote pro-environmental initiatives in the private sphere ; increase citizen knowledge and affinity for nature ; encourage the social cohesion within a village ; and promote volunteers’ empowerment and the formation of citizens communities

L’éducation relative à l’environnement pour stimuler différents niveaux d’engagement environnemental : le cas du dispositif Mon Village Espace de Biodiversité

La place accordée à l’action citoyenne dans l’espace public n’a cessé de croître depuis le XXe siècle, sans que les conséquences de telles initiatives ne soient toujours analysées. Cet article explore comment un dispositif encourageant des initiatives citoyennes pour la biodiversité, qui s’appuie sur une démarche scientifique, peut favoriser l’implication d’adultes. Il repose sur l’exemple du dispositif d’éducation à l’environnement Mon Village Espace de Biodiversité (France). Proposé aux habitants de la Zone Atelier Plaine et Val de Sèvre, ce dispositif offre une grande diversité d’entrées possibles dans l’action environnementale et à plusieurs échelles : accueillir et observer un abri à insectes dans son jardin (échelle individuelle) ; participer à la gestion d’un rucher public (échelle communale) ; rejoindre un groupe de citoyens porteurs de projets de conservation de la biodiversité (échelle du territoire). Des enquêtes qualitatives et quantitatives et un atelier d’évaluation menés en 2016 montrent que ces opportunités de contact avec la nature peuvent favoriser les actions pro-environnementales dans la sphère privée ; accroître la connaissance et l’affinité pour la nature des participants ; développer le lien social dans les communes ; promouvoir l’empowerment des volontaires et la création de collectifs.The 20th century has been marked by a larger space left for citizen participation in the public arena. However, the impact of these initiatives remains to be investigated. This article explores the way a science-based program promoting citizen initiatives for biodiversity can encourage adults’ involvement. It is based on the example of an environmental education program launched in the Long Term Ecological Research platform (LTSER) Plaine et Val de Sèvre area (France): Mon Village Espace de Biodiversité. Various levels of environmental action are proposed to inhabitants through this program. The installation and the observation of a wooden insect shelter in private gardens (individual level); the participation to the management of a public apiary (communal level); the involvement in a group of citizens leading projects for biodiversity protection (territory level). In 2016, we explored the consequences of such participations though qualitative and quantitative studies, as well as through an evaluation workshop. Our results showed that these initiatives provide opportunities to be in contact with nature, which can promote pro-environmental initiatives in the private sphere; increase citizen knowledge and affinity for nature; encourage the social cohesion within a village; and promote volunteers’ empowerment and the formation of citizens communities