Dusky hopping mouse  (Notomys fuscus)

Classified as Vulnerable (VU) on the IUCN Red List (1).

Using its long, narrow hind feet, the dusky hopping mouse can hop swiftly across its desert habitat (2). Similar to other desert rodents the dusky hopping mouse has strong incisor teeth and large ears (2). The body hair is fine and soft, with the long tail tip sprouting a protrusion of coarser hairs giving the appearance of a brush (3). The colour of its upper body fur can range from shades of pale sandy browns to darker more ashy browns, while its underparts are uniformly white (4). A notable characteristic of this rodent is its enlarged sebaceous glandular area that is found on the underside of its neck or chest. As indicated by its large black eyes, the dusky hopping mouse is a nocturnal species allowing it to avoid predators that are active during the day (2) (4) (5). 

This species range once stretched across much of South Australia and the southern Northern Territory, but is now limited to fragmented areas of South Australia, south-western Queensland and north-western New South Wales, totalling a range of less than 2,000 square kilometres (1). This range encompasses the southern Strzelecki Desert and the Cobblers Desert (6).

Preferring desert environments, the dusky hopping mouse can be found in sand dunes and plains, although it has also been spotted in lightly wooded areas and grasslands (2) (5) (7).  

The diet of the dusky hopping mouse consists mainly of vegetation such as berries, seeds and leaves, although it has been known to also occasionally eats insects (2) (3). Unusually for a mammal, the dusky hopping mouse does not need water to survive; instead it is able obtain the water it needs from its food, an adaptation that is immensely useful for a life in the desert (8). The dusky hopping mouse reproduces opportunistically with no apparent seasonality, producing litters of around one to five young, often after good rainfall (3). The gestation period of this species is between 37 and 42 days and the young are able to open their eyes at between 18 and 24 days (2). During pregnancy, the sebaceous glandular area of female dusky hopping mice becomes active and is thought to be involved in territorial marking and marking of the newborn young. The males’ glands are active at all times (2).

The dusky hopping mouse lives in burrows which are dug on the flat tops of sand dunes (9). These burrows consist of a single tunnel with up to six ventilation shafts and a nest of vegetation placed in the main tunnel (2). These burrows are a key part of their social system. Groups of around five individuals live in each burrow (3), often with burrows being interlinked to one another (2), and the mice work together socially in the construction and maintenance of the burrow. For instance, if one mouse finds that the entrance to a shaft is blocked by sand it will emit squeaks to notify others inside who will come to assist in its removal. The daytime is spent resting in these burrows (2), but at night the dusky hopping mouse ventures out to forage, although it makes sure it stays within a few metres of the safety of the burrow (3). Normally, to minimise wasting energy, the dusky hopping mouse walks in an awkward gait on all fours or uses small hops. However, if it senses danger it will use its powerful hind legs to bound away rapidly (2) (5).

Dusky hopping mice are currently suffering from a rapid population decline (10), although the reasons why are not clear (1). Populations fluctuate between seasons, along with the availability of vegetation, although the species is resilient and can survive in areas of depleted plant life (1) (2). This species is susceptible to predation by feral cats (Felis catus) and foxes (Vulpus vulpus), and competition for food from house mice (Mus domesticus) and rabbits (Oryctolagus cuniculus) (4) (10).

This species is listed as Vulnerable under several acts including the Endangered Species Protection Act (1992), the Threatened Species Conservation Act (1995), and the Environment Protection and Biodiversity Conservation Act (1999) (3) (4) (7). However, due to a lack of knowledge on population size, efforts to help in the conservation of this species are limited (3). Currently, efforts involve surveys to estimate the distribution and number of individuals in each area (9), which are being carried out by the Department of Environment and Natural Resources, and the Conservation Commission of the Northern Territory (10). Also, efforts are being made to further understand this animal’s requirements, which will result in crucial knowledge that could help inform future conservation actions (1) (4) (9).

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

To find out about wildlife conservation in Australia see:

• Australian Conservation Foundation:
  http://www.acfonline.org.au
• Department of the Environment:
  http://www.environment.gov.au/biodiversity