Red Crested Tree Rat Santamartamys rufodorsalis was ‘lost’ for 113 years (image courtesy of Lizzie Noble)
As a group, small mammals are very poorly known. And many species have been ‘lost’ to science. In other words, these are species that haven’t been observed by scientists for many years – and in some remote areas of the world, some species haven’t been recorded for over 100 years. Have they gone extinct or have we not looked hard enough? The red-crested tree rat Santamartamys rufodorsalis provides a clue to answering this question. Originally described in 1898 when two specimens were collected from the Santa Marta Mountains in Colombia, the species wasn’t seen again until 2011 when one was seen shuffling along a walkway handrail in the El Dorado Nature Reserve – that’s 113 years of being ‘lost’.
Here is our list of the Top 20 ‘Lost’ small mammals – surveys are urgently needed for these species to establish whether they are still alive today and, if so, to determine their status and conservation needs. For more information, click on each species to take you to the relevant account on the IUCN Red List of Threatened Species.
Order: Rodentia
Red List status: CR
Endemic to: India
Lost since: 1981
Order: Rodentia
Red List status: CR (PE)
Endemic to: Peru
Lost since: 1949
Order: Eulipotyphla
Red List status: CR (PE)
Endemic to: Côte d’Ivoire
Lost since: 2013
Order: Rodentia
Red List status: DD
Endemic to: Angola
Lost since: 1937
Order: Rodentia
Red List status: DD
Endemic to: South Africa
Lost since: 1922
Order: Rodentia
Red List status: CR (PE)
Endemic to: Mexico
Lost since: 1986
Order: Rodentia
Red List status: CR (PE)
Endemic to: Mexico
Lost since: 1948
Order: Rodentia
Red List status: CR
Endemic to: Indonesia
Lost since: 1920
Order: Rodentia
Red List status: DD
Endemic to: Philippines
Lost since: 1970s
Order: Rodentia
Red List status: CR
Endemic to: Chile
Lost since: 1994
Order: Rodentia
Red List status: CR (PE)
Endemic to: Cuba
Lost since: 1937
Order: Rodentia
Red List status: DD
Endemic to: Philippines
Lost since: 1953
Order: Rodentia
Red List status: CR (PE)
Endemic to: Solomon Islands
Lost since: 1888
Order: Rodentia
Red List status: DD
Endemic to: Togo (Close to Ghana border)
Lost since: 1890
Order: Rodentia
Red List status: CR (PE)
Endemic to: Solomon Islands
Lost since: 1888; possibly 1960s
Order: Rodentia
Red List status: CR (PE)
Endemic to: Indonesia
Lost since: 1946
Order: Eulipotyphla
Red List status: CR
Endemic to: Equatorial Guinea (Bioko Island)
Lost since: 1968
Order: Eulipotyphla
Red List status: CR (PE)
Endemic to: Australia (Christmas Island)
Lost since: 1985
Order: Rodentia
Red List status: CR (PE)
Endemic to: Mexico (Ángel de la Guarda Island)
Lost since: 1991
Order: Rodentia
Red List status: CR
Endemic to: Mexcio (Jalisco)
Lost since: 1998