According to Parks Canada there are 42 mammal, 180 bird, 16 fish and a few amphibian species found in the park. In the "State of the Park Report 2009" the NWT government showed ten species that the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) had listed as special concern, threatened, or endangered that Nahanni National Park Reserve provides seasonal and year-round habitat for. These include common nighthawk, grizzly bear, olive-sided flycatcher, peregrine falcon, rusty blackbird, short-eared owl, wood bison, woodland caribou, wolverine and yellow rail. In addition the bull trout (Dolly Varden) and the Nahanni aster are listed but without a status and the Canada warbler and western toad are listed as possibly existing in the park.