Influence of past and future climate changes on the distribution of three Southeast Asian murine rodents

Aim: We tested the influence of Pleistocene climatic fluctuations and the
potential effect of future climate change on Southeast Asian small mammal distributions
using two forest-dwelling (Leopoldamys herberti and Leopoldamys
sabanus) and one karst (Leopoldamys neilli) endemic rodent species as models.
Location: Southeast Asia.
Methods: We used presence–absence data of genetically identified individuals,
bioclimatic variables and species distribution modelling techniques to predict
potential distributions of the three studied species under current, past [Last
Interglacial (LIG) and Last Glacial Maximum (LGM)] and future conditions.
We applied a variety of modelling techniques and then used consensus techniques
to draw up robust maps of potential distribution ranges at all stages.
Results: According to our models, these three Leopoldamys species did not
experience significant range contraction during the LGM. Our models revealed
substantial range contraction during the LIG for L. herberti in northern Indochina,
while its distribution expanded in southern Indochina. Evidence of a
southward range expansion during that period was also obtained for L. neilli,
whereas L. sabanus remained widely distributed in insular Southeast Asia but
experienced a range contraction on the Thai-Malay Peninsula. The two future
climate change scenarios used predicted that large climatically suitable areas
would still be available in the future for the three species.
Main conclusions: Our model predictions contradict the well-established
hypothesis that Southeast Asian forest-dwelling species were confined to small
refugia during the LGM. Moreover, our results suggest that some Southeast
Asian taxa may have been distributed in their refugial state during the LIG
rather than the LGM. This could be because of vegetation changes that may
have occurred at that time as a result of the increased seasonality observed during
the LIG. These Pleistocene refugia may have been localized in northern
Indochina but our study also revealed that southern Indochina could provide
major potential refugia.