Greater big-footed mouse  (Macrotarsomys ingens)

Classified as Endangered (EN) by the IUCN Red List (1).

This small, gerbil-like mouse has relatively large eyes which hint at its nocturnal behaviour. The upperparts are light brown to fawn with slightly more greyish underfur, and the underparts and legs are paler and often creamy-white. The ears are oval shaped, and the very long tail ends in a whitish tuft. The greater big-footed mouse belongs to the subfamily Nesomyinae, a group of 20 rodent species found only in Madagascar, and is one of only two species of Macrotarsomys (2).

Found only in the Ankarafantsika forest, in the Mahajanga Province in north-west Madagascar (2) (3).

The greater big-footed mouse has been found only in dry, deciduous forest (2) (3).

The greater big-footed mouse is a nocturnal species, and is almost totally arboreal, spending nearly all of the night time in trees. During daylight hours it occupies an underground burrow, which is dug under a large rock or tree stump. These burrows have closed, concealed entrances, and can be recognised by the small piles of soil outside the entrance, thrown up during excavation (2). Like other species belonging to the subfamily Nesomyinae, the greater big-footed mouse is thought to be an herbivore, feeding on fruit, seeds, berries, roots and stems. They themselves are an important food source for a number of snakes, birds of prey and mammalian carnivores (4).

The greater big-footed mouse is very vulnerable to any threats due to its very restricted distribution. The dry, deciduous forests of Madagascar are threatened by burning to clear land for agriculture and grazing, selective logging and expanding rural human populations (5). Such habitat destruction and degradation will inevitably impact heavily on the greater big-footed mouse.

The greater big-footed mouse occurs within the Ankarafantsika National Park. Unfortunately, this area still faces the threat of frequent fires during the dry season and encroachment by grazing cattle, but international conservation organisations are working to improve the protection of the reserve (6).

View information on this species at the UNEP World Conservation Monitoring Centre.

For further information on the greater big-footed mouse see:

• The EDGE of Existence programme:
  www.edgeofexistence.org/mammals/species_info.php?id=38
• Madagascar Wildlife Conservation:
  www.mwc-info.net/en/