HMW 7 – Species accounts: Malabar Spiny Tree Mouse (Platacanthomys lasiurus)

Genus PLATACANTHOMYS
Blyth, 1859

 

1. Malabar Spiny Tree Mouse Platacanthomys lasiurus

French: Loir-épineux de Malabar / German: Südindien-Stachelbilch / Spanish: Ratón arborícola de Malabar

Other common names: Malabar Spiny Dormouse, Malabar Spiny Mouse

 

Taxonomy. Platacanthomys lasiurus Blyth, 1859, Alipi (= Allepey), Malabar (= Kerala State), India.

This species is monotypic.

Distribution. Endemic to the Western Ghats of S India, from 14° to 8° N latitude in Karnataka, Kerala, and Tamil Nadu.

Descriptive notes. Head–body 118–140 mm, tail 76–106 mm. No specific data are available for body weight. The Malabar Spiny Tree Mouse is the largest platacanthomyid, but a small rodent with large, mostly naked ears and distinctive, white-tipped, flattened spines interspersed throughout dorsal pelage. Dorsum is light brown, with lighter venter; whiskers are long; long tail is lightly furred near base but densely furred at tip (resembling a bottle brush); and hair at tip of tail is white in some individuals (including juveniles).

Habitat. Tropical evergreen forests and deciduous riparian forests at elevations of 600–900 m in the Western Ghats.

Food and Feeding. The Malabar Spiny Tree Mouse is granivorous and frugivorous. It is known to feed on fruits and seeds from more than 25 different plant species, including crops like black pepper and cacao.

Breeding. Poorly known. The Malabar Spiny Tree Mouse might have two distinct breeding seasons.

Activity patterns. Malabar Spiny Tree Mice are nocturnal and nest in leaf-lined tree cavities and rock crevices during the day, emerging to forage in the canopy after dusk.

Movements, Home range and Social organization. Home ranges of Malabar Spiny Tree Mice are c.5 ha and sometimes overlap. Mating system is possibly polygynous. Multiple adult females and their offspring will live with a single adult male in a nest, and males sometimes live alone. Individuals sometimes forage in mixed groups.

Status and Conservation. Classified as Vulnerable on The IUCN Red List in 2008. The Malabar Spiny Tree Mouse is considered a pest by some farmers and is sometimes killed. It will occasionally forage in cropland, but it tends to avoid secondary forest. Less than 2000 km2 of suitable evergreen forest remains in the Western Ghats. If habitat destruction continues and protected areas are threatened, conservation status of this endemic Indian species will likely be downgraded. It has never been included in a molecular genetic analysis, so any genetically distinct populations (or potential undescribed, morphologically similar species) are unknown.
Bibliography. Carleton & Musser (1984), Chetana & Ganesh (2013), Corbet & Hill (1992), Ganesh & Devy (2006), Gopakumar & Motwani (2013), Jayahari & Jayson (2007), Jayson (2006), Jayson & Jayahari (2009), Molur & Nameer (2008a), Molur & Singh (2009), Molur et al. (2005), Mudappa et al. (2010), Musser & Carleton (2005).

 

Genus TYPHLOMYS
Milne-Edwards, 1877

 

2. Chapa Tree Mouse Typhlomys chapensis

French: Loir-pygmée de Chapa / German: Vietnam-Zwergbilch / Spanish: Ratón arborícola de Chapa

Other common names: Chapa Pygmy Dormouse, Vietnamese Pygmy Dormouse

 

Taxonomy. Typhlomys cinereus chapensis Osgood, 1932, “Chapa [= Sa Pa], Tonkin," Lào Cai Province, Vietnam.

Typhlomys chapensis currently comprises two former subspecies of T. cinereus (chapensis and jingdongensis). Monotypic.

Distribution. SW China (W of the Red River in SW Yunnan) and NW Vietnam (Lào Cai Province).

Descriptive notes. Head–body 61–115 mm, tail 80–126 mm, weight 7·7–22·6 g. Braincase is dome-shaped. The Chapa Tree Mouse is larger than the Soft-furred Tree Mouse (T. cinereus) and the Dwarf Tree Mouse (T. nanus); dorsal pelage is dark gray to black; venter is yellowish-white; ears are large and naked; eyes are very small; whiskers are long; long tail is lightly furred near base but densely furred at tip (resembling a bottle brush); and hair at tip of tail is white in some individuals.

Habitat. Tropical montane forests above 200 m in elevation.

Food and Feeding. Poorly known. The Chapa Tree Mouse is likely granivorous and frugivorous.

Breeding. No information.

Activity patterns. Poorly known. Like other small forest-dwelling rodents, the Chapa Tree Mouse is likely nocturnal.

Movements, Home range and Social organization. Poorly studied in most respects. Recent behavioral studies of wild-caught animals in laboratory enclosures suggest that this species uses ultrasonic echolocation to navigate among tree branches. Little is known about its behavior in the wild. Like the Soft-furred Tree Mouse, it has been trapped on low branches in trees and on the ground.

Status and Conservation. Not yet assessed on The IUCN Red List. Because distribution appears to be small and it occupies threatened tropical forests, it will likely be classified as more threatened than the Soft-furred Tree Mouse after it is assessed by conservationists.
Bibliography. Abramov et al. (2014), Carleton & Musser (1984), Cheng Feng et al. (2017), Musser & Carleton (2005), Osgood (1932), Panyutina et al. (2017), Smith & Yan Xie (2008), Wu Deling & Wang Guanghuan (1984).

 

3. Soft-furred Tree Mouse Typhlomys cinereus

French: Loir-pygmée de Chine / German: China-Zwergbilch / Spanish: Ratón arborícola de pelaje suave

Other common names: Chinese Pigmy Dormouse, Pygmy Dormouse, Soft-furred Pygmy-dormouse

 

Taxonomy. Typhlomys cinereus Milne-Edwards, 1877, W. Fujian, China.

Typhlomys cinereus was formerly considered conspecific with T. chapensis and T. daloushanensis. Two subspecies recognized.

Subspecies and Distribution.

T. c. cinereus Milne-Edwards, 1877 – SE China (Anhui, Zhejiang, Jiangxi, and Fujian).

T. c. guangxiensis Wang Yingxiang & Chen Zhiping, 1996 – S China (Guangxi).

Descriptive notes. Head–body 71–76 mm, tail 96–102 mm; weight 15–32 g. Braincase is flattened. The Soft-furred Tree Mouse is the second smallest platacanthomyid; dorsal pelage is medium gray; venter is grayish white; ears are large and naked; eyes are small; whiskers are long; long tail is lightly furred near base but densely furred at tip (resembling a bottle brush); and hair at tip of tail is white in some individuals.

Habitat. Tropical and subtropical montane forests above 200 m in elevation, including bamboo stands and mixed-bamboo forests.

Food and Feeding. Poorly known. The Soft-furred Tree Mouse is likely granivorous and frugivorous, but some reports also mention that it eats leaves and stems.

Breeding. Poorly known. Litter sizes appear to be small, with 1–4 young/litter.

Activity patterns. Poorly known. The Soft-furred Tree Mouse is probably nocturnal. Some reports suggest that it might dig burrows, but this could be speculation based on its reduced eye size.

Movements, Home range and Social organization. Other than reports of its presence in certain habitats, the Soft-furred Tree Mouse has never been the focus of ecological research. Like the Chapa Tree Mouse (T. chapensis), it has been trapped both on low branches in trees and on the ground, suggesting that it is less arboreal than the Malabar Spiny Tree Mouse (Platacanthomys lasiurus). Given its close evolutionary relationship with the Chapa Tree Mouse and its similar morphology (including exceptionally small eyes), it is possible that this species also uses ultrasonic echolocation for navigation.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Soft-furred Tree Mouse has a wide distribution in China, where it has been regionally listed as least concern. Morphologically distinct and geographically isolated subspecies could be raised to full species status with additional genetic data.

Bibliography. Abramov et al. (2014), Carleton & Musser (1984), Cheng Feng et al. (2017), Cong Haiyan et al. (2013), Corbet & Hill (1992), Lunde & Smith (2008), Musser & Carleton (2005), Osgood (1932), Smith & Yan Xie (2008), Wang Yingxiang et al. (1996).

 

4. Dalou Mountains Tree Mouse Typhlomys daloushanensis

French: Loir-pygmée du Dalou Shan / German: Dalou Shan-Zwergbilch / Spanish: Ratón arborícola de Dalou

 

Taxonomy. Typhlomys cinereus daloushanensis Wang Yingxiang & Li Chongyun, 1996, “Mt. Jingfu (107° 10’ E, 29° 02’ N), Nanchuan co., soutern [sic] Sichuan, alt. 2 000 m,” China.

This species is monotypic.

Distribution. C China (SE Gansu, S Shaanxi, E Sichuan, Chongqing, W Hubei, and N Guizhou).

Descriptive notes. Head–body 72–105 mm, tail 105–129 mm; weight 15·4–31 g. The Dalou Mountains Tree Mouse is the largest species of Typhlomys. Dorsum is charcoal gray; venter is slate gray, with white hairs interspersed throughout; ears are large and naked; eyes are small; whiskers are long; long tail is lightly furred near base but densely furred at tip (resembling a bottle brush); and hair at tip of tail is white in some individuals. Braincase is flattened.

Habitat. Tropical montane forests at elevations above 200 m.

Food and Feeding. Poorly known, but the Dalou Mountains Tree Mouse is probably granivorous and frugivorous.

Breeding. No information.

Activity patterns. Poorly known, but the Dalou Mountains Tree Mouse is probably nocturnal as are other forest-dwelling rodents.

Movements, Home range and Social organization. Poorly known, but given its close evolutionary relationship with the Chapa Tree Mouse (T. chapensis) and similar morphologies (including exceptionally small eyes), it is possible that the Dalou Mountains Tree Mouse also uses ultrasonic echolocation for navigation.

Status and Conservation. Not yet assessed on The IUCN Red List.

Bibliography. Carleton & Musser (1984), Cheng Feng et al. (2017), Musser & Carleton (2005), Smith & Yan Xie (2008), Wang Yingxiang et al. (1996).

 

5. Dwarf Tree Mouse Typhlomys nanus

French: Loir-pygmée du Jiaozi / German: Zwergbilch / Spanish: Ratón arborícola enano

 

Taxonomy. Typhlomys nanus Cheng Feng et al., 2017, “Mt. Jiaozi (26° 08’ N, 102° 85’ E), Wumeng township, Luquan County, Kunming, Yunnan, China; elevation approximately 3,252 m asl.”

This species is monotypic.

Distribution. Known only from Mt Jiaozi and Mt Dawei in Yunnan (SW China).

Descriptive notes. Head–body 65–74 mm, tail 97–106 mm; weight 8·8–13·2 g. The Dwarf Tree Mouse is the smallest species of Typhlomys. Pelage is distinctly bicolored, with ash-gray dorsum and creamy white venter and cheeks; ears are large and naked; eyes are small; whiskers are long; long tail is lightly furred near base but densely furred at tip (resembling a bottle brush); and hair at tip of tail is white in some individuals. Braincase is dome-shaped.

Habitat. Only known from secondary forests on two mountains at elevations of 2000–3000 m. Forests had acidic, red soil and were composed mostly of George’s fir (Abies forrestii var. georgei, Pinaceae) with undergrowth of bamboo and rhododendron (Rhododendron, Ericaceae).

Food and Feeding. Poorly known, but the Dwarf Tree Mouse is probably granivorous and frugivorous.

Breeding. No information.

Activity patterns. Poorly known, but the Dwarf Tree Mouse is probably nocturnal as are other forest-dwelling rodents.

Movements, Home range and Social organization. Poorly known, but given its close evolutionary relationship with the Chapa Tree Mouse (T. chapensis) and similar morphologies (including exceptionally small eyes), it is possible that the Dwarf Tree Mouse also uses ultrasonic echolocation for navigation.

Status and Conservation. Not assessed on The IUCN Red List.

Bibliography. Cheng Feng et al. (2017).