The High Jura boasts a strong diversity of wildlife, with the current census of species of vertebrates standing at 205. The mammals and birds are specifically adapted to survive the mountain forest and peak environment. Some species are deemed symbolic of the Jura, such as the Capercaillie, the Hazel Grouse, the Eurasian lynx, the Golden Eagle and the Eurasian Three-toed Woodpecker.

• Of the 143 species of birds inventoried, 91 are nesting and 127 are protected at the national level. Surprisingly, this is not the case either for the most emblematic of Jura species, the Capercaillie, or for the “star” of the Tetraonidae family, the Hazel Grouse; however they have not been hunted in the Jura Massif since 1974.
• The Reserve shelters the only true population of mountain Red Deer in the Department of Ain and in the Jura Massif. This population is increasing.
• The most important population of Chamois in the Jura Massif roam the scree, the grassy plateaus or the understorey of the forests in search of their food, agilely scampering across the Jura slopes, depending on the hour of day and the season.
• With regard to bats, 23 species have been counted in the High Jura.
• 7 species of reptiles and amphibians are represented in the Reserve: The Common Lizard, the Green and the Yellow Whipsnake, the Yellow-bellied Toad, the Alpine Newt and the Common Frog.

In the still under-researched insect world, 932 species have been identified out of which a certain number have been declared of interest at the national and/or international level, but it is estimated that there could be hundreds, even thousands, yet to be inventoried!