he rarest Caucasian leopard (Panthera pardus ciscaucasica = P.p. saxicolor) and still common, but decreasing, bezoar goat (Capra aegagrus) inhabit the hardly accessible rocky areas. Both these mammals are included to the 2007 IUCN Red List of Threatened Species and the Red Data Book of Armenia: Animals (1987). European marbled polecat (Vormela peregusna peregusna) living in grasslands is listed in the 2007 IUCN Red List of Threatened Species and the Red Data Book of Armenia. The Syrian brown bear (Ursus arctos syriacus) is included to the Red Data Book of Armenia. Two more mammals included to the national Red Data Book are supposedly living in Khosrov Reserve: the Asian barbastelle (Barbastella leucomelas) and European wild cat (Felis silvestris silvestris).
Five bird species occurring in Khosrov Reserve are listed in the 2007 IUCN Red List of Threatened Species: the Eurasian black vulture (Aegypius monachus), pallid harrier (Circus macrourus), lesser kestrel (Falco naumanni), European roller (Coracias garrulus) and semi-collared flycatcher (Ficedula semitorquata). Thirty-seven birds are listed in the Red Data Book of Armenia: Animals (1987), but 16 more should also be added which are rare, have limited distribution or decline in numbers. These species are the European honey buzzard (Pernis apivorus), black kite (Milvus migrans), Egyptian vulture (Neophron percnopterus), northern goshawk (Accipiter gentilis), lesser spotted eagle (Aquila pomarina), booted eagle (Hieraaetus pennatus), Eurasian eagle owl (Bubo bubo) and others. Nesting sites of the Mongolian finch (Bucanetes mongolicus), Tengmalm's owl (Aegolius funereus) and Eurasian black vulture are located only in Khosrov Reserve. This protected area contains the largest colony of the Eurasian griffon vulture (Gyps fulvus) and one of two nesting sites for the red-tailed wheatear (Oenanthe chrysopygia) in the country.
Among the reptiles, the Armenian viper (Vipera raddei) living on the rocky slopes and the common tortoise (Testudo graeca) from semi-deserts are listed in the 2007 IUCN Red List of Threatened Species. The species listed in the national Red Data Book: Animals (1987) are the golden grass mabuya (Trachylepis septemtaeniata), Schneider's skink (Eumeces schneideri), European cat snake (Telescopus fallax), black-headed rhynchocalamus (Rhynchocalamus melanocephalus satunini) and Transcaucasian rat snake (Elaphe hohenackeri).
The only amphibian listed in the Red Data Book of Armenia: Animals (1987) is the Syrian spadefoot (Pelobates syriacus).