Aegialomys galapagoensis

Galapagos Rice Rat
(Aegialomys galapagoensis galapagoensis)

syn. Mus galapagoensis galapagoensis, Oryzomys galapagoensis galapagoensis


Ecuador: Isla San Cristóbal (Chatham Island) / Galápagos Islands

local name: -

size: ca. 27 cm (length)

extinction date: sometimes after 1835

The nominate race of the Galapagos Rice Rat once lived on the Isla San Cristóbal, also known as Chatham Island, were it was discovered and described by Charles Darwin in the year 1835.

This Rice Rat had a size of about 27 cm (snout to tail tip).

Not much is known about its living, the same applies to its relatives, other endemic Rice Rat species, that still live on some of the Galapagos Islands. In contrast to so many of the obviously tame animals that these islands are famous for, the endemic Rice Rats are nocturnal, very shy and seemingly fearful.


An exact extinction date can not be given.

The introduction of House Mice (Mus domesticus) and Ship Rats (Rattus rattus) is thought to be responsible for the extinction of the nominate race of that species. These rodents are food competitors on the one hand, and on the other hand especially the Ship Rats may not have resiled from killing the Galapagos Rice Rats, at least their offspring.


The much smaller Isla Santa Fe, also known as Barrington Island, is home of another Rice Rat form which was formerly regarded as a distinct species, this form is now treated as a subspecies of the Galapagos Rice Rat, (Aegialomys galapagoensis bauri).


Galapagos Rice Rat (Aegialomys galapagoensis galapagoensis)

Depiction from 'Darwin, C. R. ed. 1838. Mammalia Part 2 No. 3 of The zoology of the voyage of H.M.S. Beagle. By George R. Waterhouse. Edited and superintended by Charles Darwin. London: Smith Elder and Co.'

by courtesy and with permission from Dr. John van Wyhe

The Complete Work of Charles Darwin Online