344.

Little Native Mouse

Pseudomys delicatulus

French: Pseudomys délicat / German: Kleine Australienmaus / Spanish: Raton nativo pequeno

Other common names: Delicate Mouse, Delicate Pseudomys, Mollinipi

Taxonomy. Mus delicatulus Gould, 1842,

Port Essington, Northern Territory, Australia.

Pseudomys delicatus was placed in genus Leggadina by J. R. Ellerman in 1941, but this treatment has not been followed by other authors. Mus albirostris is a synonym of delicatulus, as also is P. mimulus; P. pilligaensis was synonymized with delicatulus by B. Breed and F. Ford in 2007 and by S. Van Dyck and R. Strahan in 2008, butits status

is poorly resolved. Taxonomy is still unsettled, with genetic evidence indicating likelihood that individuals in lower-rainfall areas of north-west Australia may represent an undescribed species. Two subspecies recognized.

Subspecies and Distribution.

P d. delicatulus Gould, 1842 — monsoonal NW & NC Australia, from Pilbara to far NW Queensland, and including the islands of Tent, Augustus, Bigge, Sir Graham Moore, Bathurst, Melville, Marchinbar, Groote Eylandt, and Sir Edward Pellew Group (West, South West, North, and Vanderlin). P. d. pumilus Troughton, 1936 — NE & CE Australia from Cape York S to NE New South Wales, including Fraser I; also reported from Trans Fly plains in S New Guinea.

Descriptive notes. Head-body 55-75 mm, tail 55-80 mm, ear 10-12 mm, hindfoot 14-19 mm; weight 6-15 g. A very small mouse, yellow brown to gray brown above, white orcream below. Slendertail usually slightly longer than head-body length.

Habitat. The Little Native Mouse occurs in a wide range of vegetation types, including tropical savannas, eucalypt open forests and woodlands, shrublands, tussock grasslands, hummock grasslands, but typically on sandy soils.

Food and Feeding. The Little Native Mouse has a varied diet; it is mostly granivorous (taking particularly grass seeds), but also eats fruits, invertebrates, and leaf and stem material.

Breeding. In the north, the Little Native Mouse breeds mostly in the dry season and in the southern part of its range mainly in spring and summer, but in at least some areas breeding occurs mostly in the dry season orparticularly at times of increased food availability. Females can produce litters in successive months; typical litter size 3-4. Gestation lasts c.30 days.

Activity patterns. Little Native Mice are terrestrial and nocturnal, sheltering during day in burrow systems, which can be extensive and complex.

Movements, Home range and Social organization. The Little Native Mouse is probably largely sedentary. There are few estimates of density, but one study reported monthly fluctuations between about ten and 110 individuals known to be alive on a 45ha sampled area. Social systems are not well known, but at least four individuals have been reported from one burrow.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Little Native Mouse has retained an extensive range and remains at least locally common. It responds positively to early succession stages after fire and disturbance by livestock.

Bibliography. Abbott & Burbidge (1995), Baverstock et al. (1981), Braithwaite & Brady (1993), Breed, B. & Ford (2007), Breed, W.G. (2000), Diete et al. (2015), Ellerman (1941), Firth, Woinarski, Brennan & Hempel (2006), Ford (2006), Iredale &Troughton (1934), Jackson & Groves (2015), Longman (1916), Ride (1970), Taylor & Calaby (2004), Taylor & Horner (1970), Van Dyck & Strahan (2008), Waithman (1979), Watts & Aslin (1981), Woinarski, Armstrong et al. (2010), Woinarski, Braithwaite et al. (1992), Woinarski, Milne et al. (2001), Woinarski, Palmer et al. (1999), Woinarski, Ward et al. (2011).