342.

Dusky Hopping Mouse

Notomys fuscus

French: Notomys brun / German: Dunkle Australienhipfmaus / Spanish: Raton saltador oscuro

Taxonomy. Ascopharynx fuscus Wood Jones, 1925,

Ooldea District, South Australia, Australia.

Notomys fuscus has in the past been synonymized by different authors with N. cervinus and with N. alexis; its specific distinction was recognized by W. D. L.. Ride in 1970 and followed by subsequent authors. Proposed form N. filmer: (from near Birdsville, SW Queensland) is a synonym of N. fuscus, as also is N. f. eyreius (from Mulka, on east side of Lake Eyre). Monotypic.

Distribution. Restricted to arid inland Australia, including E edge of the Simpson Desert in far SW Queensland, the S Strzelecki Desert in South Australia, and the far NW New South Wales, with some expansion following periods of high rainfall and occasional records outside main known range.

Descriptive notes. Head-body 76-115 mm, tail 115-155 mm, ear 23-29 mm, hindfoot 33-39 mm; weight 26-55 g. The Dusky Hopping Mouse has body form typical of hopping mice, with very long hindfeet, long tail with distal brush of longer hairs, long ears, and large eyes. Itis characterized by a large and deep throat pouch with distinct fleshy margins and covering ofstiff white hairs, present in both sexes. Upper body color is light orange to gray; belly fur is silky and white.

Habitat. Associated mostly with sand dunes and other sandy areas, other than those dominated by hummock grassland (7riodia, Poaceae) vegetation. Occurs also in clay flats, stony (“gibber”) flats, and rocky ranges, but in such environments typically where there are at least some sandy areas.

Food and Feeding. Dusky Hopping Mice are mostly granivorous, but also eat other plant material (stems, leaves) and occasionally invertebrates.

Breeding. Reproduction is aseasonal and partly opportunistic, with high reproductive output from continuous breeding following periods of high rainfall. Littersize is 1-5, most commonly three; gestation period 38-41 days. Sexual maturity is reached at 75-90 days old.

Activity patterns. The Dusky Hopping Mouse is terrestrial and nocturnal, sheltering during day in deep burrow systems.

Movements, Home range and Social organization. Dusky Hopping Mice are social, with groups of about five individuals occupying a burrow system. Some subpopulations may be relatively stable, but others exhibit pronounced changes in density (“boom-bust” cycles) associated with variation in rainfall. Radio-tracked individuals have been recorded as moving up to 1-5km over three nights. Low recoveries of marked individuals in monitoring studies indicate that a proportion of the population is transient.

Status and Conservation. Classified as Vulnerable on The IUCN Red List and listed as vulnerable under Australian legislation. Rationaleforlisting is small area of occupancy (during drought years), fragmented distribution, and extreme population fluctuations. Historic decline probably due mainly to habitat degradation caused by livestock and introduced European Rabbits (Oryctolagus cuniculus), and predation by the introduced Red Fox (Vulpes vulpes) and feral cat. Subfossil and historical records demonstrate that the Dusky Hopping Mouse’s current range is a substantial reduction from that at the time of European settlement of Australia.

Bibliography. Aitken (1968), Brazenor (1934), Burbidge et al. (2008), Finlayson (1960), Iredale & Troughton (1934), Jackson & Groves (2015), Letnic et al. (2009), Mack (1961), Moseby, Brandle & Adams (1999), Moseby, Owens et al. (2006), Murray et al. (1999), Ride (1970), Tate (1951), Val et al. (2012), Van Dyck & Strahan (2008), Watts & Aslin (1981), Waudby & How (2008), Woinarski et al. (2014), Wood Jones (1925).