Nicobar Archipelago Rat

discussion

Discussion: Rattus rattus species group. Recent morphometric analyses indicate R. burrus to be most closely related to R. simalurensis from the Simalur Arch., R. lugens from the Mentawai Arch., and R. adustus from Pulau Enggano. Except for larger body size, morphology of the four species resembles that characterizing the R. tiomanicus complex from the Sunda Shelf (Musser, 1986; Musser, ms.). Rattus burrus is also morphologically similar to R. palmarum from Car Nicobar, the northernmost of the Nicobar Isls (see that account), but differs in being smaller in body size (e. g., greatest skull length = 41.3 - 46.7 mm for 12 adult R. burrus, 49.0 - 54.0 mm for three adult R. palmarum), with softer pelage. Whether burrus is a separate species or simply a smaller-bodied insular variant of the larger-bodied and coarse-furred R. palmarum warrants careful study. Both taxa may be Nicobar endemics, but their status will have to be tested by a systematic revision of the R. tiomanicus complex. Corbet and Hill (1992) questionably included burrus and burrescens as synonyms of R. tiomanicus and regarded burrulus, which we treat as a synonym of R. andamanensis (see that account), as possibly conspeci

Order Rodentia - Family Muridae

distribution

Distribution: Islands of Trinkat, Little Nicobar, and Great Nicobar in the Nicobar Arch.; apparently absent from Car Nicobar, northernmost of the Nicobar Isls, which is inhabited by populations of R. andamanensis and R. palmarum (see those accounts).

Order Rodentia - Family Muridae

discussion

COMMENTS: Except for larger body size, morphology closely resembles that of most samples of R. tiomanicus from the Sunda Shelf. Whether burrus is an endemic of the Nicobars or whether samples from the three islands are insular variants of R. tiomanicus needs to be tested by a systematic revision of the R. tiomanicus complex (Musser, 1986; Musser and Califia, 1982; Musser and Heaney, 1985).

Order Rodentia - Family Muridae

distribution

DISTRIBUTION: Islands of Trinkat, Little Nicobar, and Great Nicobar in the Nicobar Archipelago.

Order Rodentia - Family Muridae