Niviventer confucianus (Milne-Edwards 1871)

[Niviventer] confucianus (Milne-Edwards 1871), Nouv. Arch. Mus. Hist. Nat. Paris, 7 (Bull.): 93.

Type Locality: China, Szechwan, Moupin.

Vernacular Names: Confucian Niviventer.

Synonyms: Niviventer canorus (Thomas 1911); Niviventer chihliensis (Thomas 1917); Niviventer deqinensis Deng and Wang 2000; Niviventer elegans (Shih 1931); Niviventer littoreus (Cabrera 1922); Niviventer luticolor (Thomas 1908); Niviventer mentosus (Thomas 1916); Niviventer naoniuensis (Zhang and Zhao 1984); Niviventer sacer (Thomas 1908); Niviventer sinianus (Shih 1931); Niviventer yajiangensis Deng and Wang 2000; Niviventer yushuensis (Wang and Zheng 1981); Niviventer zappeyi (G. M. Allen 1912).

Distribution: N Burma and mainland China (from Yunnan and W Sichuan west to Fujian and north to Jilin Province; Wang, 2003, and Zhang et al., 1997); also mountains of NW Thailand (summit Doi Inthanon, Chiengmai Province) and extreme NW Vietnam (summit Mt Fan Si Pan west of the Red River); may also be found on summits of mountains in N Laos; not recorded from islands off coast of China. Because of past confusion of N. confucianus with N. tenaster, N. niviventer, and N. fulvescens, the range outlined here is derived primarily from Musser’s identification of specimens in AMNH, BMNH, FMNH, MCZ, MVZ, and USNM.

Conservation: IUCN – Lower Risk (lc).

Discussion: Usually included in N. niviventer, but that allocation is not supported by present evidence (Abe, 1983; Corbet and Hill, 1992; Musser, 1981 b; Musser and Lunde, ms). Niviventer confucianus is basically endemic to SE portion of the Palearctic region east of the Himalayas and generally north of the Tropic of Cancer; south of that line, this northern species has been found only on mountaintops in NW Thailand and NW Vietnam. Sympatric with N. fulvescens and an undescribed larger-bodied species in N Burma, with N. fulvescens in S China, with and with N. andersoni and N. confucianus in highlands of Sichuan. Niviventer confucianus is replaced westward in the Himalayas by the smaller-bodied N. niviventer and in mountains south of the Tropic of Cancer by the larger-bodied and montane N. tenaster (Musser and Lunde, ms). In NW Vietnam, N. confucianus is found near summit of Mt Fan Si Pan with N. tenaster and N. fulvescens occuring at lower altitudes (Musser and Lunde, ms). Westward range boundary is unresolved. Dimensions of Chakraborty’s (1975) specimen of " Rattus niviventer niviventer " from W Bhutan are too large for N. niviventer, match those typical of N. confucianus, and may represent that species, as could the samples from NE India treated as N. niviventer by Agrawal (2000). If so, the westward range of N. confucianus would extend to Bhutan but no farther; another look at the Bhutan and NE Indian series would resolve the issue (see account of N. niviventer).

Morphometric analyses (Musser and Lunde, ms) indicates N. confucianus to be most closely related to N. tenaster, an alliance supported by analysis of mtDNA cytochrome b sequences (J. L. Patton, in litt., 2000). Geographic variation in body size and pelage coloration is conspicuous within N. confucianus, but its significance has yet to be revealed by careful systematic revision. Wang and Zheng (1981) reported results from a systematic study under the name of Rattus niviventer, and described yushuensis as a subspecies. Zhang and Zhao (1984) proposed naoniuensis as a subspecies. Deng et al. (2000) diagnosed yajiangensis from W Sichuan and deqinensis from NW Yunnan as subspecies of Niviventer confucianus. Deng et al. (2000) also suggested that ten subspecies be recognized in N. confucianus; one of these, lotipes, represents N. tenaster (see that account), and another, culturatus, is treated here as a separate species (see account).

Chromosomal characteristics documented for Thai (Markvong et al., 1973) and Chinese (Wang et al., 1997) samples. Ecological relationship with N. fulvescens and other murines in S Yunnan reported by Wu et al. (1996). Morphology of digestive tract related to energy metabolism in N. confucianus (reported as Rattus niviventer confucianus) versus Rattus norvegicus presented by Bao et al. (1998).