Distributions of mammals in Southeast Asia: The role of the legacy of climate and species body mass

Abstract

Aim Current species distributions are shaped by present and past biotic and abiotic factors. Here, we assessed whether abiotic factors (habitat availability) in combination with past connectivity and a biotic factor (body mass) can explain the unique distribution pattern of Southeast Asian mammals, which are separated by the enigmatic biogeographic transition zone, the Isthmus of Kra (IoK), for which no strong geophysical barrier exists. Location Southeast Asia. Taxon Mammals. Methods We projected habitat suitability for 125 mammal species using climate data for the present period and for two historic periods: mid‐Holocene (6 ka) and last glacial maximum (LGM 21 ka). Next, we employed a phylogenetic linear model to assess how present species distributions were affected by the suitability of areas in these different periods, habitat connectivity during LGM and species body mass. Results Our results show that cooler climate during LGM provided suitable habitat south of IoK for species presently distributed north of IoK (in mainland Indochina). However, the potentially suitable habitat for these Indochinese species did not stretch very far southwards onto the exposed Sunda Shelf. Instead, we found that the emerged landmasses connecting Borneo and Sumatra provided suitable habitat for forest dependent Sundaic species. We show that for species whose current distribution ranges are mainly located in Indochina, the area of the distribution range that is located south of IoK is explained by the suitability of habitat in the past and present in combination with the species body mass. Main conclusions We demonstrate that a strong geophysical barrier may not be necessary for maintaining a biogeographic transition zone for mammals, but that instead a combination of abiotic and biotic factors may suffice.

Closely related species show species-specific environmental responses and different spatial conservation needs: Prionailurus cats in the Indian subcontinent

“…For P. bengalensis , increased suitability from the LIG to LGM is in agreement to climatic suitability expansion found for forest rodent species during the same period in Southeast Asia 100 . Also, a tendency for higher, but overlapping, suitable climatic area during the LGM compared to the mid Holocene resembles the pattern described for other Indochinese mammals 101 . Moreover, considerable genetic differentiation has been found between northern and southern Indian Leopard Cat populations 40 , which may have been exacerbated by late Holocene environmental events, as predicted by the drop in climatic suitability from the mid Holocene to the present time.…”

Potential distribution of two lynx species in europe under paleoclimatological scenarios and anthropogenic climate change scenarios

“…Climate is the most important environmental factor affecting the distribution of species from past to present. Climate change led to a change in biodiversity and ecosystems in the past (Radchuk et al, 2019). The fact that biodiversity is higher in some regions than in other regions indicates that climate change is not everywhere at the same speed (Sandel et al, 2011).…”