363.

Heath Mouse

Pseudomys shortridgei

French: Pseudomys de Shortridge / German: Heide-Australienmaus / Spanish: Raton de brezo

Other common names: Dayang, Heath Pseudomys, Heath Rat, Shortridge’s Native Mouse

Taxonomy. Mus shortridgei Thomas, 1907,

“Woyerline [= Woyerling], east of Pinjelly [Western Australia, Australia], 970° [= 299 mj}.” G. H. H. Tate in 1951 classified P. shortridge: within genus Pseudomys, but genetic studies, as well as sperm-head morphology, have shown thatit is distant from others in that genus. F. Ford’s 2006 molecular study placed it in same clade as P. desertor and P. oralis; this was supported by B. Breed and Ford in 2007 and a phylogeny by P. Smissen and K. C. Rowe in H.J. McLennan and colleagues’ 2017 study. P. shortridge: now occurs as two geographically well-separated populations, one in south-west Victoria and the other in south-west Western Australia; according to studies by N. K. Cooper and colleagues in 2003 and M. Salinas and team in 2009, these constitute two divergent lineages and could eventually be listed as separate subspecies. Monotypic.

Distribution. SW & SE Australia. Wheatbelt region and S parts of Western Australia, including N of Burngup, near Lake Biddy, Dragon Rocks Nature Reserve, Lake Magenta Nature Reserve, Fitzgerald River National Park, and the Ravensthorpe Range area; also in SW Victoria, including the Grampians and extending S to Lower Glenelg National Park and into the SE tip of South Australia.

Descriptive notes. Head-body 90-120 mm, tail 85-100 mm, ear 14-16 mm, hindfoot 26-28 mm; weight 55-90 g. The Heath Mouse is a rather large Pseudomys . It has a graybrown dorsal pelage and a pale buff-black ventral region. It is also characterized by a “blunt-looking” face and a hairy, bicolored tail which is similar in length to head-body length.

Habitat. Dry heathland, open woodlands, mixed scrub, and mallee. The Heath Mouse is well adapted to periodic occurrence of fires. It prefers locations with significant amount of grass, flowers, and fungi in regenerating heathland. Dry heathland that has been burnt within preceding 5-15 years is favored habitat, as well as dry stringybark ( Eucalyptus baxteri and E. arenacea, Myrtaceae) open woodland and open forest with a heath understory. It is known, however, to occupy various habitats. In Western Australia it prefers mature stands of scrub, mallee, and mixed scrub with Banksia (Proteaceae) on loamy soils that have not been burnt for at least 30 years.

Food and Feeding. The Heath Mouse is omnivorous. It is mainly herbivorous, but feeds also on seeds, insects, flowers, sedge stems, and fungi.

Breeding. Reproduction takes place in late spring and summer. Average litter size is 2-3, and twolitters may be produced per season.

Activity patterns. Heath Mice are terrestrial. They are partly diurnal, and shelter in a nest built in shallow burrows or under dense ground cover.

Movements, Home range and Social organization. A study of social organization suggests the occurrence of stable pair bonds,at least during the four months of the breeding season.

Status and Conservation. Classified as Near Threatened on The IUCN Red List. The Heath Mouse has a range of less than 2000 km* and is found in very fragmented populations. Many threats have been reported, which include predation by feral cats and Red Foxes (Vulpes vulpes), habitat degradation, and inappropriate fire regimes. The species was thought extinct in Western Australia by C. H. S. Watts and H. J. Aslin in 1981, but, after an apparent absence of 56 years, it was rediscovered in south-west Western Australia by A. Baynes and colleagues in 1987, since then it has been collected in several localities.

Bibliography. Baynes et al. (1987), Breed & Ford (2007), Cooper, Bertozzi et al. (2003), Ford (2006), McLennan et al. (2017), Menkhorst (1995), Menkhorst et al. (2008), Salinas et al. (2009), Tate (1951), Watts & Aslin (1981).