Pygmy Mouse

Scientific name:  Mus minutoides

Common names:  Pygmy Mouse; African Pygmy Mouse; Dwergmuis (Afr)

This is the smallest of the African rodent species and is closely related to the House Mouse Mus musculus.  They have a total length, including the tail, of about 11cm with tails that are about 80% of the length of the head and body.  Their mean weight is about 5,5g.

The upper parts of the body are brownish-buff.  The brownish colour is imparted by the presence of black-tipped hairs, which become fewer on the flanks, which are orange-buffy.  The border between the colour of the flanks and the white of the under parts is sharply defined.  The tail is brown above and buffy below, the ears brownish, the hands and feet are buffy-white.

By studying different populations of African Mus minutoides, the researchers have observed a very high proportion of fertile females carrying XY chromosomes (between 74% and 100%).  This is in contrast to normal female mammals which have XX chromosomes and males having XY chromosomes.  The reason for this deviation from the norm is unknown at this stage.

Pygmy mice are very small and their size is illustrated in this photograph where the body is compared to an old 2c coin.

Distribution

They occur in the Western Cape Province,  Eastern Cape Province, KwaZulu-Natal, Mpumalanga, Free State, Mozambique and Eastern Zimbabwe.

Habitat

They have a wide habitat tolerance.They occur in the Karoo, savanna grassland and woodland.  They occur where the annual rainfall is from 100mm to 1000mm per annum.

Habits

They are nocturnal and terrestrial.  They are not a communal species, and the burrows are used only by a single pair and their family.  In soft ground they will construct burrows but it is more common to find them under fallen logs, in piles of debris, boulders or holes in termite mounds.

They forage singly at night and may not be closely tied to a single shelter.

They are aggressive towards each other in captivity.

Food

Some green vegetative matter is eaten, but the main food items are grass seeds, insects and termites.

Reproduction

They breed during the wet, warm summer months.  Courtship involves grooming of the female by the male.  He nuzzles her neck as she sits in a hunched position with her face averted.  Attempts to copulate may be rejected at first by the female by kicking with her hind feet, but otherwise she shows no signs of aggression.

The gestation period is 19 days or less.  The male occupies the nest with the female and her litter and takes part in the defence of the litter.

The young are bright pink at birth and their eyes are closed.

Weaning occurs 19 days after birth.  The first successful mating takes place at an age of 42 days.