Bear claw marks in clay: differential conservation in caves harboring bat colonies. Mas d'Azil, Sirach and Lare caves, France ; La conservation différentielle des griffades d’ours dans l’argile dans les grottes abritant des colonies de chauves‐souris : grottes de Mas d’Azil, de Sirach et de la Lare.

International audience ; Numerous traces of bear visits have been found in caves. They generally correspond to claw marks on walls or to cave bear wallows. Sometimes, these clues are not always well preserved and do not allow the confident identification of the presence of bears. The differential preservation of clue on limestone walls can hamper speleologists and paleontologists in their diagnoses. One must not interpret the absence of claw marks on the rock walls of a cave as an absence of bears. In addition to condensation‐corrosion, biocorrosion, due in particular to the pervasive presence of bats in a cave, should be considered as a significant process responsible for the removal of traces on limestone walls. After briefly presenting the speleogenetic processes caused by bats, we present the French caves of Mas d'Azil (Ariège), Sirach (Pyrénées‐Orientales) and Lare (Alpes-de‐Haute‐Provence), which have been frequented by bears, to demonstrate these processes. Here, only the claw marks in the clay are preserved, while their extensions on the limestone walls have completely disappeared. These observations confirm that the clues of bear frequentation are preserved in a different way, depending on the history of the cave, but also on the nature of support, rocky or clayey, on which they were produced. ; Des nombreux indices de fréquentation par des ours ont été relevés dans lesgrottes ; le plus souvent il s'agit de griffades ou de bauges. Parfois, ces indices ne sont pas toujours conservés et ne permettentpas d'identifier l'ours. La conservation variable des traces sur les parois calcaires peut gêner les spéléologues et paléontologues dans leur diagnostic. Il n'est pas possible d'interpréter l'absence de griffades sur les parois rocheuses d'une cavité comme une absence des ours. En effet, la condensation‐corrosion, mais surtout la biocorrosion due notamment à la présence massive de chiroptères dans une grotte, peuvent être responsables de la disparition des traces sur les parois calcaires. Après avoir rappelé ...