The fauna in the National Park of Tzoumerka, Peristeri, and Arachthos Gorge includes a significant number of terrestrial, aquatic, and flying invertebrates, amphibians, reptiles, birds, and mammals. Regarding vertebrates, a total of 197 species have been recorded, while the existing studies on invertebrates are limited, and the number of species living in the area’s habitats remains unknown to this day. Many species of butterflies, as well as moths, live in the alpine meadows. Some butterfly species have limited global distribution and make rare appearances in the Greek territory in this area.

In addition to Lepidoptera, endemism is observed in other insect families such as Orthoptera, Coleoptera, and terrestrial invertebrates, which, although not well-known to the general public, have significant scientific and biogeographical value.

In the crystal-clear waters of the tributaries of Arachthos and Achelous, there are 7 species of fish, while certain pure populations of the wild trout are still preserved. In the streams, wet alpine meadows, and seasonal ponds of the area, 6 species of amphibians reproduce. The Greek frog (Rana graeca) lives near the beds of mountain streams, the yellow-bellied toad is found in wet areas with vegetation, while newts and salamanders find refuge in the forests after the breeding season.

In the different habitats of the park, 19 species of reptiles find refuge (1 land turtle, 8 species of lizards and 10 species of snakes). Populations of many species of this misunderstood group of animals have declined due to pressures from human activities. Reptiles are important to ecosystems and food chains, both as predators and as prey. All species of reptiles are protected according to Greek and European legislation, while for some species, such as snakes (Elaphe quatuorlineata, Zamenis situla) and the Mediterranean turtle (Testudo hermanni), a stricter protection framework applies, and as a country we have undertaken the obligation to implement specific measures to protect their populations. In addition, the presence of the meadow viper (Vipera ursinii), which is an endemic subspecies of the Pindos mountain range, was recorded for the first time in the National Park.

The area is home to a significant number of ostriches and birds of prey (about 150 species). The presence of many species of predators, as well as many large mammals, also justifies the necessity of establishing the area as a National Park. A total of 36 species of predators of the Accipitridae and Falconidae families are found here. Among them stand out the golden eagle (Aquila chrysaetos), the vulture (Gyps fulvus), the rock kestrel (Falco tinnunculus), the petrel (Falco peregrinus), etc. In the coniferous forests, 7 species of woodpeckers nest, among them the black woodpecker (Dryocopus martius), while the steep slopes of Lakmos and Tzoumerka are a suitable nesting habitat for several mountain species, such as the snow shrike (Montifringilla nivalis) and the snow shrike (Eremophila alpestris), which search for their prey in the alpine and subalpine meadows of the area.

The National Park of Tzoumerka, Peristeri and Arachthos Gorge is a particularly important area for mammals, as in the different habitats of the area the presence of ¼ of the species of mammals found in Greece has been recorded (30 species of mammals belonging to 17 families). In more detail, 4 species of insectivores (Insectivora), one species of lagomorpha (Lagomorpha), 8 species of rodents (Rodentia), 4 species of ungulates (Artiodactyla) and 8 species of carnivorous mammals live in the area.

At least 5 species of chiroptera (families Rhinilophidae and Vespertilionidae) live in caves and rock crevices, which need special protection due to the destruction of their habitats.

The presence of the brown bear (Ursus arctos) is noticeable in most of the National Park, as it moves long distances to satisfy its food needs. The wider area constitutes the southwestern boundary of the bear’s geographical distribution in our country. The wildcat (Felis sylvestris) is an impressive feline that can surprise you if you decide to cross the forested paths of the National Park. Skilled trackers will surely find characteristic traces of the otter (Lutra lutra) along the riverbanks, although its populations have significantly decreased in recent years worldwide due to human encroachment and food reduction.

The chamois (Rupicapra rupicapra balcanica) maintains small populations in the Tzoumerka Mountains and is found on inclined slopes covered with forests, which lead up to steep peaks with cliffs, ravines, and more or less horizontal ridges with abundant lush vegetation, usually adjacent to subalpine meadows depending on the altitude. The presence of the roe deer (Capreolus capreolus) is an indication of the diversity and variety of the ecosystems in the National Park.

Regarding livestock breeds, it is worth mentioning the breeding of the Kalarrites sheep breed (boutsiko) by the residents of the villages Kalarrites and Syrrako. The old shepherds claim that these sheep originated from the crossbreeding of the Mountainous Epirotic sheep with the comisana breed, members of which were brought from Sicily in the mid-18th century by Syrrako merchants with the aim of producing higher quality wool. The total population of this breed in Greece amounts to 5,000 sheep.