River bank

Permanent edge of a watercourse, located above the normal water level. The river bank is characterized by its cross-sectional shape (gently sloping bank, steep bank), its composition (sand, marl), its vegetation (herbaceous, shrub. Frequently subject to overflow and erosion from the stream, the banks are habitats for many species. They allow the passage of discrete animals like water rat, muskrat, water shrew or the Pyrenean desman. Some changes in the water level allow boulders to appear and form excellent perches for the dipper. Sand martins enjoy the banks to do their nest. Crawfish, fish and macroinvertebrates use shelters on the banks to hide, breed or feed.