If the airport planned for the commune of Notre-Dame-des-Landes had been built, it would have been located on 1,426 hectares of miraculously preserved bocage and wetlands and would have led to the destruction of many protected animal and plant species. The promoters of the airport project were aware of the ecological interest of the Notre-Dame-des-Landes site (the Biotope study office was mandated by the project leaders to carry out an inventory. The final report showed the interest of the site for amphibians and birds and lists 74 species protected by French law). However, their entire argument was based on the fact that they would be able to compensate for the enormous loss of biodiversity caused by the project. Nature protection associations believed that the loss of biodiversity on the site could in no way be compensated. Faced with this risk, a group of professional and amateur naturalists decided to come together in order to carry out a second expertise by carrying out a systematic inventory of the natural habitats, flora and fauna present on the moor, the results thus obtained serving to feed the legal files filed by the nature protection associations with the courts. After 3 years of inventories (2013 – 2015), the result obtained by the Naturalists in Struggle is clear: more than 2,000 species have been inventoried, 130 protected species recorded (and not 74), 5 species unknown in France discovered and dozens unknown in the Loire Atlantique department. Beyond the figures which reinforce the ecological interest of the site, it is the method which should be noted. The outings organized by the Naturalists in Struggle on the second Sunday of each month were open to all. Whoever wanted came with their knowledge and skills and pooled them, shared them. We came to learn and to participate in the fight against the airport. Because it was the collective work carried out by the volunteer naturalists which blocked the work. I participated in 5 outings bringing my own skills; The photographs taken were made available to naturalists who can use them as they wish. This book is a tribute to their meticulous work.