Calomyscus baluchi, Thomas, 1920

Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Calomyscidae, Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona: Lynx Edicions, pp. 144-155 : 153-154

3.

Pakistan Brush-tailed Mouse

Calomyscus baluchi

French: Calomysque du Baloutchistan / German: Belutschistan-Maushamster / Spanish: Raton de cola de cepillo de Pakistan

Other common names: Baluchi Brush-tailed Mouse, Baluchi Calomyscus, Baluchi Mouse-like Hamster, Pakistan Calomyscus, Pakistan Mouse-tailed Hamster

Taxonomy. Calomyscus baluchi Thomas, 1920 ,

“ Kelat District, Baluchistan ,” W Pakistan .

Calomyscus baluchi was originally described as a distinct but closely related species to C. bailwardi that could be differentiated by its smaller ears and longer palatine foramina. Latter revisions treated it as a subspecies of C. bailward: until N. N. Vorontsov and colleagues in 1979 conducted a comprehensive revision of the genus that elevated it to a distinct species. They noted, however, that the two species were morphologically very similar but their distributions were separated by presence of a morphologically distinct species, C. hotsoni . Results of molecular phylogenetics analyses support the specific status of C. baluchi and its close relationship with C. bailwardi . No karyotypic data are available. Two subspecies recognized, but preliminary phylogeographic analysis failed to provide support for their recognition, analyses with greater geographic coverage are needed.

Subspecies and Distribution.

C.b.baluchiThomas,1920—ECAfghanistan(SKoh-i-BabaMts)andWPakistan(NWaziristantoBalochistan).

C. b. mustersi Ellerman, 1948 — NE & NC Afghanistan and NW Pakistan (N Federally Administered Tribal Areas and W Khyber Pakhtunkhwa Province).

Descriptive notes. Head-body 73-97 mm, tail 63-102 mm, ear 16-21 mm, hindfoot 18-25 mm; weight 15-30 g. The Pakistan Brush-tailed Mouse is morphologically similar to the Zagros Mountains Brush-tailed Mouse ( C. bailwardi ) but has smaller ears (mean 17-6 mm compared to 19-4 mm) and long palatal foramina. Two subspecies have been described that are morphologically similar but differ in color, with nominate baluchi a sandy buff and mustersi a rather grizzled drab gray. Skull is similar to the Zagros Mountains Brush-tailed Mouse with condylobasal lengths of 20-2-23-6 mm and zygomatic breadths of 11-2-13-2 mm but averages somewhat narrower in breadth (12:5 mm compared to 12:7 mm).

Habitat. Primarily steppic forest with junipers ( Juniperus macropoda, Cupressaceae ) and pistachios ( Pistacia khinjuk, Anacardiaceae ) in areas with rocky terrain at elevations of 400-3500 m. In the northern parts of its distribution, the Pakistan Brushtailed Mouse also has been found in areas with evergreen oaks ( Quercus sp. , Fagaceae ). While primarily found in dry, rocky hills, rock walls, and stone piles, the Pakistan Brush-tailed Mouse has also been collected from burrows excavated by the Persian Jird (Meriones persicus) but is notably absent from valley floors that are devoid of exposed rocks.

Food and Feeding. The Pakistan Brush-tailed Mouse is granivorous, caching seeds in their burrows and concealing them understones. It feeds on acorns and seeds of various herbs and grasses and also feeds on buds and flowers of various forbs. In winter in the northern part of its distribution,it likely subsists on stored food items.

Breeding. Breeding of the Pakistan Brush-tailed Mouse is reportedly confined to warmer months from spring to late autumn. A female captured in late March produced two young in early April. Two females captured in mid-July each had three embryos.

Activity patterns. Pakistan Brush-tailed Mice are very agile and able to climb and jump among rocks and boulders. They are strictly nocturnal during warmer months, but in colder weather, they are often active in the afternoon and early morning hours. They are susceptible to exposure to temperatures approaching freezing and often succumb to such exposures. It is unclear as to whether brush-tailed mice use daily torpor. They are active throughout the year and are not known to hibernate.

Movements, Home range and Social organization. Pakistan Brush-tailed Mice are not highly social but are quite gregarious in favorable habitats with multiple individuals sharing the same burrow. In captivity, they sleep huddled together.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Populations are known to occur in Chitral Gol and Hazarganji-Chiltan national parks in western Pakistan.

Bibliography. Akbarirad et al. (2016b, 2016c), Corbet (1978), Ellerman (1941, 1948), Ellerman & Morrison-Scott (1951), Hassinger (1973), Molur et al. (2005), Norris, Morshed et al. (2003), Norris, Woods & Kilpatrick (2008), Roberts (1997), Shahabi et al. (2013), Vorontsov et al. (1979).

Figures

1. Zagros Mountains Brush-tailed Mouse (Calomyscus bailwardi), 2. Hotson’s Brush-tailed Mouse (Calomyscus hotsoni), 3. Pakistan Brush-tailed Mouse (Calomyscus baluchi), 4. Great Balkhan Brush-tailed Mouse (Calomyscus mystax), 5. Goodwin's Brush-tailed Mouse (Calomyscus elburzensis), 6. Noble Brush-tailed Mouse (Calomyscus grands), 7. Urar Brush-tailed Mouse (Calomyscus urartensis), 8. Syrian Brush-tailed Mouse (Calomyscus tsolovi)

Subspecies and Distribution. C.b.baluchiThomas,1920—ECAfghanistan(SKoh-i-BabaMts)andWPakistan(NWaziristantoBalochistan). C. b. mustersi Ellerman, 1948 — NE & NC Afghanistan and NW Pakistan (N Federally Administered Tribal Areas and W Khyber Pakhtunkhwa Province).