34 research outputs found
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 entraßné 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. Grùce à un dispositif expérimental de terrain (63 parcelles, 170 ha) situé
dans le marais de Brouage (Charente-Maritime), nous avons cherché à restaurer le caractÚre
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 printaniĂšre 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 trĂšs significatifs dans 1'utilisation de 1'espace sont intervenus chez cette espĂšce, mais ces changements n'auraient
pu ĂȘtre dĂ©tectĂ©s en 3 annĂ©es 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 mĂȘme plan d'eau le jour et la nuit. Cette Ă©tude a Ă©tĂ© menĂ©e sur un plan d'eau de moins d'un hectare, utilisĂ© par des Sarcelles d'hiver (Anas crecca) Ă 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. âhygroregulation hypothesisâ) 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 âimprintâ 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 tĂtulo original âHoneybee conservation centres in western Europe - an innovative strategy using sustainable beekeeping to reduce honeybee declineâ, foi um dos 10 aprovados na ĂĄrea da biodiversidade do 5Âș concurso transnacional (2013-2014) BiodivErsA/FACCE-JPI (http://www.biodiversa.org/766), subordinado ao tema âPromover sinergias e reduzir o compromisso entre o abastecimento de alimentos, biodiversidade e serviços dos ecossistemasâ. A diversidade nativa das populaçÔes de abelha melĂfera (Apis mellifera) da linhagem da Europa ocidental (M) tem vindo a ser crescentemente ameaçada pela introdução massiva de colĂłnias da linhagem da Europa oriental (C, onde se incluem as subespĂ©cies A. m. ligustica, A. m. carnica, A. m. macedĂłnica etc.), e tambĂ©m por outros fatores biĂłticos (Varroa e vĂrus associados, Nosema etc.) e abiĂłticos (pesticidas, perda e fragmentação de habitat, alteraçÔes climĂĄticas etc.). Ă neste contexto que surge o projeto BEEHOPE, o qual tem por objetivo Ășltimo contribuir para a conservação da diversidade genĂ©tica das populaçÔes de abelha melĂfera 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 gĂ©nĂ©ral deux types dâhabitats distincts au cours des 24 heures, les oiseaux se reposant en grand nombre la journĂ©e sur quelques plans dâeau de grande taille, et se dispersant la nuit pour sâalimenter sur de nombreuses zones plus petites. Dans certains cas, les canards peuvent toutefois utiliser le mĂȘme plan dâeau le jour et la nuit. Cette Ă©tude a Ă©tĂ© menĂ©e sur un plan dâeau de moins dâun hectare, utilisĂ© par des Sarcelles dâhiver (Anas crecca) Ă la fois le jour et la nuit au dĂ©but de lâhiver. Le nombre de canards nâĂ©tait pas liĂ© Ă lâabondance des ressources alimentaires, aux niveaux dâeau ou Ă la surface du bassin. Leur budget-temps nâĂ©tait pas diffĂ©rent entre le jour et la nuit, lâalimentation Ă©tant toujours lâactivitĂ© principale. Lâimportance des activitĂ©s de confort a dĂ©clinĂ© avec lâaugmentation des niveaux dâeau et de la surface du bassin, qui a pu augmenter le risque de prĂ©dation potentielle. Cette Ă©tude permet de mieux comprendre les facteurs rĂ©gissant lâutilisation de zones dâalimentation diurnes par les sarcelles dâhiver.Guillemain Matthieu, Houte Sylvie, Fritz HervĂ©. Activities and food resources of wintering Teal (Anas crecca) in a diurnal feeding site : a case study in western France. In: Revue d'Ăcologie (La Terre et La Vie), tome 55, n°2, 2000. pp. 171-181
Restauration hydraulique dâun marais et consĂ©quences pour les oiseaux : contraintes dâĂ©chelles dâespace et de temps dans les processus Ă©cologiques
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 dâannĂ©es, lâintensification de lâagriculture par le drainage et la mise en culture a entraĂźnĂ© la perte des fonctions hydrauliques et Ă©cologiques des marais de la façade atlantique. Conservation et rĂ©habilitation de la biodiversitĂ© de ces milieux sont Ă lâorigine de notre Ă©tude. GrĂące Ă un dispositif expĂ©rimental de terrain (63 parcelles, 170 ha) situĂ© dans le marais de Brouage (Charente-Maritime), nous avons cherchĂ© Ă restaurer le caractĂšre humide des prairies naturelles en manipulant la gestion hydraulique et pastorale, et en mesurant les consĂ©quences sur les oiseaux. Les parcelles en prairie ont Ă©tĂ© soumises Ă trois «scĂ©narios » de gestion hydraulique : le scĂ©nario «sec» (durĂ©e dâinondation minimale), le scĂ©nario «intermĂ©diaire» (inondation dâenviron 6 mois) et le scĂ©nario «humide» (inondation dâenviron 10 mois). Entre 1997 et 2001, des dĂ©nombrements exhaustifs des passereaux nicheurs (Alouette des champs Alauda arvensis et Bergeronnette printaniĂšre Motacilla flava), ont montrĂ© quâĂ une Ă©chelle temporelle de cinq ans, il est possible dâenregistrer des Ă©volutions dâabondance des populations (baisse de la densitĂ© des alouettes et augmentation de celle des bergeronnettes) en fonction du degrĂ© dâhumiditĂ© dans la parcelle. Par ailleurs, le suivi de la dynamique des populations du Vanneau huppĂ© (Vanellus vanellus) a montrĂ© que lâĂ©chelle spatiale choisie (170 ha) nâĂ©tait pas adaptĂ©e et quâil fallait prendre en compte lâensemble du marais, soit 12 000 hectares. Sur le plan temporel, des changements trĂšs significatifs dans lâutilisation de lâespace sont intervenus chez cette espĂšce, mais ces changements nâauraient pu ĂȘtre dĂ©tectĂ©s en 3 annĂ©es seulement.Bretagnolle Vincent, Houte Sylvie, Boileau Nicolas. Restauration hydraulique dâun marais et consĂ©quences pour les oiseaux : contraintes dâĂ©chelles dâespace et de temps dans les processus Ă©cologiques . In: Revue d'Ăcologie. SupplĂ©ment 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 âErikaâ oil spill has killed more seabirds than any before
in Europe: nearly 70Â 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, âERIKA-Avionâ, 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
LâĂ©ducation relative Ă lâenvironnement pour stimuler diffĂ©rents niveaux dâengagement environnemental : le cas du dispositif Mon Village Espace de BiodiversitĂ©
La place accordĂ©e Ă lâaction citoyenne dans lâespace public nâa cessĂ© de croĂźtre depuis le XXe siĂšcle, sans que les consĂ©quences de telles initiatives ne soient toujours analysĂ©es. Cet article explore comment un dispositif encourageant des initiatives citoyennes pour la biodiversitĂ©, qui sâappuie sur une dĂ©marche scientifique, peut favoriser lâimplication dâadultes. Il repose sur lâexemple du dispositif dâĂ©ducation Ă lâenvironnement Mon Village Espace de BiodiversitĂ© (France). ProposĂ© aux habitants de la Zone Atelier Plaine et Val de SĂšvre, ce dispositif offre une grande diversitĂ© dâentrĂ©es possibles dans lâaction environnementale et Ă plusieurs Ă©chelles : accueillir et observer un abri Ă insectes dans son jardin (Ă©chelle individuelle) ; participer Ă la gestion dâun rucher public (Ă©chelle communale) ; rejoindre un groupe de citoyens porteurs de projets de conservation de la biodiversitĂ© (Ă©chelle du territoire). Des enquĂȘtes qualitatives et quantitatives et un atelier dâĂ©valuation menĂ©s en 2016 montrent que ces opportunitĂ©s de contact avec la nature peuvent favoriser les actions pro-environnementales dans la sphĂšre privĂ©e ; accroĂźtre la connaissance et lâaffinitĂ© pour la nature des participants ; dĂ©velopper le lien social dans les communes ; promouvoir lâempowerment des volontaires et la crĂ©ation 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 adultsâ 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 SĂšvre area (France) : Mon Village Espace de BiodiversitĂ©. 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 volunteersâ empowerment and the formation of citizens communities
LâĂ©ducation relative Ă lâenvironnement pour stimuler diffĂ©rents niveaux dâengagement environnemental : le cas du dispositif Mon Village Espace de BiodiversitĂ©
La place accordĂ©e Ă lâaction citoyenne dans lâespace public nâa cessĂ© de croĂźtre depuis le XXe siĂšcle, sans que les consĂ©quences de telles initiatives ne soient toujours analysĂ©es. Cet article explore comment un dispositif encourageant des initiatives citoyennes pour la biodiversitĂ©, qui sâappuie sur une dĂ©marche scientifique, peut favoriser lâimplication dâadultes. Il repose sur lâexemple du dispositif dâĂ©ducation Ă lâenvironnement Mon Village Espace de BiodiversitĂ© (France). ProposĂ© aux habitants de la Zone Atelier Plaine et Val de SĂšvre, ce dispositif offre une grande diversitĂ© dâentrĂ©es possibles dans lâaction environnementale et Ă plusieurs Ă©chelles : accueillir et observer un abri Ă insectes dans son jardin (Ă©chelle individuelle) ; participer Ă la gestion dâun rucher public (Ă©chelle communale) ; rejoindre un groupe de citoyens porteurs de projets de conservation de la biodiversitĂ© (Ă©chelle du territoire). Des enquĂȘtes qualitatives et quantitatives et un atelier dâĂ©valuation menĂ©s en 2016 montrent que ces opportunitĂ©s de contact avec la nature peuvent favoriser les actions pro-environnementales dans la sphĂšre privĂ©e ; accroĂźtre la connaissance et lâaffinitĂ© pour la nature des participants ; dĂ©velopper le lien social dans les communes ; promouvoir lâempowerment des volontaires et la crĂ©ation 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 adultsâ 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 SĂšvre area (France): Mon Village Espace de BiodiversitĂ©. 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 volunteersâ empowerment and the formation of citizens communities