352.

Shark Bay Mouse

Pseudomys fieldi

French: Pseudomys de Field / German: Field-Australienmaus / Spanish: Raton de Shark

Other common names: Alice Springs Mouse, Djoongari, Shark Bay Pseudomys

Taxonomy. Mus fieldi Waite, 1896,

Alice Springs, southern Northern Territory, Australia.

P. fieldi was recognized by various authors, including G. H. H. Tate in 1951, as a mem-ber of subgenus Tethomys under the name P. praeconis; praeconis was synonymized with P. fieldi by R. Strahan in 1995, an opinion followed since that time. In molecular phylogeny by F. Ford in 2006 and B. Breed and Ford in 2007, P. field: forms a group

with P. australis and P. higginsi, and a phylogeny by P. Smissen and K. C.Rowe in H. J. McLennan and colleagues’ 2017 study supported P. field: as sister taxon of P. higginsi . Further taxonomic revision is needed for all of these clades. Monotypic.

Distribution. Bernier I and Faure I, Shark Bay, Western Australia; introduced to North West I, Montebello Is, and Doole I, Western Australia.

Descriptive notes. Head—body 85-115 mm, tail 115-125 mm, ear 19 mm, hindfoot 24— 27 mm; weight 30-61 g. The Shark Bay Mouse has a grizzled dark brown dorsal pelage, which becomes bufflaterally and pure white below. Hairs are long and shaggy. Tail is hairy and gray above and white below, and is longer than head-body length.

Habitat. Coastal dune vegetation dominated by beach spinifex ( Spinifex longifolius, Poaceae), coastal daisybush ( Olearia axillaris, Asteraceae), and open grasslands with Triodia (Poaceae) and Acacia (Fabaceae) .

Food and Feeding. The Shark Bay Mouse is omnivorous. Diet is composed of flowers (likely from the coastal daisybush), leaves, and stems from fleshy plant species, as well as fungi, insects, and spiders in various proportions.

Breeding. Breeding occurs May-November in the wild, but is continuous in captivity. Gestation period c.28 days; females give birth to 3—4 young, which are weaned at ¢.30 days. Both sexes become mature by 65 days of age. In captivity, average litter size was 3-6 (range 1-6 at birth).

Activity patterns. Shark Bay Mice are terrestrial and nocturnal; they digburrows in which they rest during day, and which they use for breeding.

Movements, Home range and Social organization. The Shark Bay Mouse is not very social, and in captivity aggression occurs between males; avoidance behavior between adults has been reported.

Status and Conservation. CITES Appendix I (as P. fieldi praeconis). Classified as Vulnerable on The IUCN Red List. The Shark Bay Mouse has been declared extinct in the Northern Territory butis still found on some islands off the north-western coast. of Western Australia It has been successfully introduced to North West Island, in Montebello Islands, in 1999 and reintroduced to Faure Island, Shark Bay, Western Australia, in 2002. Thus, it now occurs as three new subpopulations at these locations.

Bibliography. Breed & Ford (2007), Ford (2006), Lambert et al. (2016), McLennan et al. (2017), Morris & Robinson (2008), Ride et al. (1962), Robinson et al. (1976), Tate (1951), Strahan (1995), Watts & Aslin (1981), Woinarski et al. (2014).