Skip to content

EDGE Mammals

Mammals exist in a great variety of forms. From the tiny Bumblebee Bat, possibly the world’s smallest mammal, to the mighty blue whale, the world’s largest, and many of the most weird and wonderful animals on earth are EDGE species. These unique and threatened animals are on the edge of existence.

A glance at the Top 25 EDGE mammals is all it takes to appreciate the extraordinary diversity of mammalian life threatened with extinction. The list includes the Mountain Pygmy Possum, the only hibernating Australian marsupial, and the Aye-aye – the world’s largest nocturnal mammal. The list includes the egg-laying echidnas of New Zealand, some of the most primitive mammals alive today whose closest relative is the platypus. It also includes the Cuban Solenodon, which is a large shrew-like animal that has a venomous bite.

The venomous solenodon (L) and egg-laying echidna (R) are two of the more strange EDGE mammals. Credit: Eladio Fernandez (solenodon); Pavel German (echidna).


In addition to strange and poorly-known species, the full EDGE list also contains some of the world’s most well-known animals, such as the orangutan, gorilla, elephant and rhinoceros. All of these species, plus many others you will probably never have known, are threatened with extinction, and are in urgent need of conservation attention. The threats to EDGE mammals are as diverse as the species they imperil, and range from habitat loss and hunting to tourism and war.

The ten most common threats to Top 100 EDGE Mammals. Numbers represent the number of species impacted by each threat. Data from IUCN Red List.


Alarmingly, over 20% of mammals are threatened with extinction and more than 50% of EDGE mammals are currently receiving little or no conservation attention. Many of the most poorly-known species are in danger of slipping towards extinction unnoticed. The aim of the EDGE of Existence programme is to prevent this from happening. Shortly before the launch of the first ever EDGE Mammals List, in January 2007, it was reported that the Yangtze River dolphin — then the number one EDGE mammal — was thought to have become extinct. We need to act now to ensure that this tragedy is not repeated.

Click here to view to the Top 25 EDGE mammals.

Click here for the latest EDGE Mammals List.

When creating our EDGE mammals list, we follow the taxonomy of the IUCN Red List.