List of mammals of the Cook Islands
This is a list of the mammal species recorded in the Cook Islands. There are seven mammal species in the Cook Islands, of which one is labelled as being a vulnerable species.
The following tags are used to highlight each species' conservation status as assessed by the International Union for Conservation of Nature:
| EX | Extinct | No reasonable doubt that the last individual has died. |
| EW | Extinct in the wild | Known only to survive in captivity or as a naturalized populations well outside its previous range. |
| CR | Critically endangered | The species is in imminent risk of extinction in the wild. |
| EN | Endangered | The species is facing an extremely high risk of extinction in the wild. |
| VU | Vulnerable | The species is facing a high risk of extinction in the wild. |
| NT | Near threatened | The species does not meet any of the criteria that would categorise it as risking extinction but it is likely to do so in the future. |
| LC | Least concern | There are no current identifiable risks to the species. |
| DD | Data deficient | There is inadequate information to make an assessment of the risks to this species. |
Order: [Chiroptera] (bats)
The bats' most distinguishing feature is that their forelimbs are developed as wings, making them the only mammals capable of flight. Bat species account for about 20% of all mammals.- Family: Pteropodidae
- *Subfamily: Pteropodinae
- **Genus: Pteropus
- *** Insular flying-fox, Pteropus tonganus LR/lc
Order: [Cetacea] (whales)
The order Cetacea includes whales, dolphins and porpoises. They are the mammals most fully adapted to aquatic life with a spindle-shaped nearly hairless body, protected by a thick layer of blubber, and forelimbs and tail modified to provide propulsion underwater.- Suborder: Mysticeti
- *Family: Balaenopteridae
- **Subfamily: Megapterinae
- ***Genus: Megaptera
- **** Humpback whale, Megaptera novaeangliae VU
- Suborder: Odontoceti
- *Superfamily: Platanistoidea
- **Family: Ziphidae
- ***Subfamily: Hyperoodontinae
- ****Genus: Mesoplodon
- ***** Ginkgo-toothed beaked whale, Mesoplodon ginkgodens DD
- **Family: Delphinidae
- ***Genus: Stenella
- **** Spinner dolphin, Stenella longirostris LR/cd
- ***Genus: Lagenodelphis
- **** Fraser's dolphin, Lagenodelphis hosei DD
- ***Genus: Feresa
- **** Pygmy killer whale, Feresa attenuata DD
Order: [Carnivora] (carnivorans)
There are over 260 species of carnivorans, the majority of which feed primarily on meat. They have a characteristic skull shape and dentition.- Suborder: Caniformia
- *Family: Phocidae
- **Genus: Hydrurga
- *** Leopard seal, Hydrurga leptonyx LR/lc