You are here :
The delta of the Camargue is a wetland of international importance. It is a vast alluvial plain dotted with ponds, marshes, salt flats, crops and animal breeding located in relation to the salinity of water and soil.
The mosaic of landscapes, the wealth of invertebrates, and wildlife of common interest correspond to the ecological requirements and conservation of the Great Horseshoe Bat (important breeding colony) and some other species of bats in search summer hunting grounds.
The building heritage (agricultural barns, historic buildings) also provide an invaluable home to bats who come to give birth and raise their young.
The study area in the Camargue is called geomorphologic, it includes the Grande Camargue, the Petite Camargue, Camargue gardoise and Plan du Bourg (with the exception of the industrial area of Golfe de Fos located in the extreme south-east).
LAWS PROTECTING THE STUDY AREA
At international level:
- Two Ramsar sites,
- The Biosphere Reserve of Camargue, situated between the Rhône River and the Mediterranean Sea, covering the whole of the biogeographic delta of Rhone, since its overhaul carried out in 2006.
At national level:
- The Camargue National Reserve,
- Eleven « Conservatoire du Littoral » sites,
- Five sites listed under the Landscape Act.
At regional level:
- The Regional Natural Park of the Camargue (PACA),
- Three regional nature reserves,
- The Natural Areas of Ecological Interest Fauna and Flora.
SCIENTIFIC DESCRIPTION OF THE STUDY AREA
The landscape of the Camargue and its environment are characterized by two major variables, salinity and flooding / drainage, this activity means the topography is much reduced (max elevation. 2 m). The salinity has a north-south gradient over the delta and interferes with variable flooding / drying, defined by the rain, floods, tides, evaporation and, nowadays, by dredging out to sea and in the two branches of the river.
These two variables are related to the unpredictability of the Mediterranean climate: in relation to the differences of temperature, sunlight or humidity, most environments are subject to a rapid change from submerged to dry, as well as from weak to very salty. As well as these variables, add also the origin of the soil which is defined by a sandy west-east gradient and sandy clay loam. The result of these attributes is a great diversity of environments and landscapes, spatially distributed in the form of a mosaic subject to unpredictable changes over time, which ensure that the richness and originality of the Camargue rests on a triptych of diversity, variability and unpredictability.
The rise and fall of the shoreline, as much as the deviations of the Rhone River, have made the delta instable for a long time. The hydraulic conversions carried out at the end of the nineteenth century have affected this general scheme by wiping out almost completely the effects of flooding and river incursions, significantly reducing natural freshwater inflow which is now limited to rain, but also substantially reducing the effects of unpredictable weather conditions in favour of controlled intake of seawater and freshwater (from Isenmann et al., 2004).
IMPORTANCE OF THE PROJECT AREA FOR THE CONSERVATION OF THE TWO TARGET SPECIES
The Camargue has a high biodiversity of flora and fauna all within a unique habitat (eg 350 species of birds, 34 mammals, many invertebrates and natural habitats, etc.).. Currently, the Camargue region has probably the most significant biological importance in the western Mediterranean (PNRC, 2003).
These findings are also true in terms of bats, since 17 of the 30 species observed in the Provence-Alpes-Côte d'Azur region, 34 from France, (Godineau and Pain, 2007) and 25 from the 40 in Europe (Temple and Terry, 2007) have been seen in the Camargue.
The Camargue is home to about 550 breeding Greater Horseshoe Bat females divided into 2 colonies totalling 200 individuals in the immediate vicinity of Natura 2000 sites (source: GCP). By its size and apparent strength, the Greater Horseshoe Bat from the Camargue is likely to be key in the maintenance of the species in the French Mediterranean and even Europe, where it could support the population of the adjacent colonies. The predicted benefit of the actions under the framework of the LIFE + Chiro Med therefore extend beyond the site. These reasons justify the choice of the site for the project. The good relationship between the size of the site and the size of the population of bats is a gauge of efficiency: focused on a reasonable area of intervention, actions will have an increased yield and efficiency.
Concerning Geoffroy‘s Bat, the Camargue hosts about 330 breeding females in 2 colonies, and 1 colony of 80 individuals very close by. The species mingle with the Greater Horseshoe Bat (source: GCP). This population is important in the context of the generally poor state of the conservation of the species. Above all, the systematic cohabitation of its breeding colonies with those of the Greater Horseshoe Bat and their use of similar hunting grounds make actions concerning them consistent.