The major part of the present LKCNHM mammal collection acquired after 1900, was from various collecting expeditions to different parts of Southeast Asia by many zoologists and associates of the Raffles Museum.
There was extensive collecting of mammals between 1900 to 1940 mainly by H. C. Robinson, C. Boden Kloss and F. N. Chasen. The more noteworthy of these expeditions are those to the Malay Peninsula, Thailand (Meklong and Nakhon Si Thammarat), Vietnam, Cambodia, Java, Sumatra (Gunong Kerinci), Borneo (Mount Kinabalu) and adjacent islands. The collection forms the primary source for F. N. Chasen's A hand list of Malaysian mammals and many other publications on Malayan fauna. Other contributors to the mammal collection include M. W. F. Tweedie, C. A. Gibson-Hill, J. C. Moulton, R. Hanitsch, C. Dover, N. Smedley,
Among the LKCNHM's mammal collection, the primates, with 867 catalogued specimens, are probably the best represented. The LKCNHM also has large collections of rats, squirrels and bats. The mammal collection has 315 species and some 15,000 specimens. Some of these are parts of the type series of taxa described by Robinson, Kloss and Chasen.
Major publications based on LKCNHM material include the following:
• Chasen, F. N., 1940. A handlist of Malaysian mammals. Bulletin of the Raffles Museum, 15: xx+209 pp.
• Robinson, H. C. & C. Boden Kloss, 1918. Results of an expedition to Korinchi Peak, Sumatra - mammals. Journal of the Federated Malay States Museums, 7: 1-80.
• Weitzel, V., C. M. Yang & C. P. Groves, 1988. A catalogue of Primates in the Singapore Raffles Museum of Biodiversity Research. The Raffles Bulletin of Zoology, 36 (1): 1-163.