[DREAL OCCITANIA] PNA Desman of the Pyrenees — Exploration effort in Occitania

‘National action plans for the conservation or recovery of the species referred to in Articles L.411-1 and L.411-2 and of species of pollinating insects shall be drawn up and after consultation with the public, implemented on the basis of the data of the relevant scientific institutes where justified by the biological situation of those species. These plans take into account economic, social and cultural requirements as well as the imperatives of national defence. The prescribed information shall also be available to them throughout the duration of the plans, in the relevant geographical areas. A decree shall specify, where necessary, the detailed rules for the application of this Article.’ In view of the difficulty in detecting the Desman des Pyrénées, modelling work has made it possible to estimate the probability of detection of the species throughout its French range and to determine the number of crossings to be carried out at least in order to be 95 % sure that Desman is absent if it has never been detected during the passage. When carrying out an inventory, it is therefore necessary to carry out at least three passages on the same section before considering the species absent. However, the number of repetitions required varies according to the sectors. Two classes were thus distinguished: areas requiring at least 3 passages and those where the necessary prospecting effort is higher and requires 5 passages. However, if a Desman Pyrenees crotte is observed before the number of passages indicated on the map has been made, it is not necessary to carry out the following passages because the species has already been detected. 3 passages: sectors requiring at least three passages along the same section in order to conclude, in the event of undetected evidence, that the species is not present 5 passages: sectors requiring at least 5 passages along the same section to conclude, in the event of failure to detect evidence, that the species is not present For more information: www.desman-life.fr (Communication tools/Technical documents)