A prime feature of the Park’s fauna is the high number of insect species present, due to the considerable environmental variety of the protected area. For example, up to now the following have been recorded:
- over 1100 species of butterflies, including 70% of all the macrolepidoptera known in the entire Valle d’Aosta and 4 species of microlepidoptera new to science;
- 22 species of Dytiscidae and Helophoridae beetles in the wetlands;
- 111 species of phytophagous beetles of the forest (32 of which have never been reported before in Valle d’Aosta).

The vertebrates include all the mammals and birds of mountain environment widespread in the region, among which Alpine Ibex, Mountain Hare, Golden Eagle, Northern Goshawk, Rock Ptarmigan, Black Grouse, Rock Partridge, Boreal Owl Eurasian Pigmy-owl, Black Woodpecker, Rufous-tailed Rock-thrush, Red-billed Chough and Northern Nutcracker.
The populations of vertebrates in Val Chalamy tend to be smaller owing to the difficult environmental conditions and reduced food availability; forest species are an exception, favoured by the large expanse of the woods.

The sighting of well-known mammals, such as the Alpine Marmot, Alpine Ibex and Alpine Chamois, is easier in the Dondena valley where there are large alpine grasslands interspersed with rock deposits. Micromammals are not particularly abundant and, in many environments, there are more Soricidae (Common Shrew and Pigmy Shrew) than rodents (mice and voles).

Over 120 species of birds have been observed in the park so far, more than 90 of which are nesting. The forest birdlife is quite rich and includes highly localised species such as the Eurasian Woocock. Diurnal birds of prey are numerous in the middle-lower Val Chalamy and on the ridges of the central valley, the only sector full of small and medium-sized prey (at least 26 pairs belonging to 8 different species nest on an area of only 20 square kilometres). The two pairs of Golden Eagle frequent territories that include, in addition to the park, the right side of the Dora Baltea river between Pontey and Issogne and the entire head of the Champorcher valley.
In addition to the diurnal birds of prey, other bird species have been the subject of extensive studies in the area of Mont Avic:
- the Rock Ptarmigan, a precious glacial relict linked to the alpine tundra, is present above an altitude of 2100-2200m in all suitable areas of the Park;
- the Black Grouse, a characteristic guest of forests with blueberry and rhododendron undergrowth, is constantly monitored in spring at the time of mating dances by the males and subsequently investigated to determine their reproductive success and for identifying wintering sites (this bird digs an igloo in powdery snow in which it spends all night and most of the day during winter);
- the Black Woodpecker, of which there is a pair every 300 hectares of woodland and which are studied with the aid of radio-telemetry equipment (birds fitted with small emitting radios to constantly locate their position);
- the Northern Nutcracker, a corvid usually linked to the Arolla Pine in the Alps and here in an environmental situation similar to that known for central and northern Europe: coniferous forests for nesting and groves of hazel bushes for gathering autumn-winter nourishment (the species collects the fruits in late summer and stores them in underground hiding places).

Two species of amphibians and fish, the Common Frog and the Trout, populate the Park’s wetlands in large numbers.

Aquila reale
Arvicola rossastra
Ballerina gialla
Ballerina gialla
Cincia alpestre
Cincia dal ciuffo
Cincia mora
Codirosso spazzacamino
Coronella girondica
Lucertola muraiola
Passero solitario
Picchio muraiolo
Picchio verde
3_28_36 PARCRI.tif_807x1293
Rondine montana
3_28_38 RUPRUP.tif_860x538