It is believed that some 30 mammals are found in and around the Ilgaz Mountains. Abundant and all-year-long running streams as well as rich vegetation enable well-matched conditions for the habitat of fauna such as deer (Cervidae), roe deer (Capreolus capreolus), wild boar (Sus scrofa), grey wolf (Canis lupus), brown bear (Ursus arctos), red fox (Vulpes vulpes), wildcat (Felis silvestris), lynx, European pine marten (Martes martes), beech marten (Martes foina), weasel, rabbit, squirrel, hedgehog, mole, bat, European badger (Meles meles) and European otter (Lutra lutra). Studies showed the existence of 617 taxa in and around the national park.