The alluvial terraces of the Seine and their forests have been integrated into a Special Protection Area dedicated to birds since 2006. There, stone curlews lay their eggs that melt into the pebbles on the banks. In moist riparian forests, black woodpeckers nest in old wood (100 to 500 years old) while herons build their nests in the tops of trees. The moist woodlands are also home to numerous sphagnum moss and protected ferns, some regionally threatened like the mountain fern and the royal fern.