The microscopic identification of mammal species from hair samples

[摘要] English: The expansion of the game ranching industry in South Africa has benefited predators such as the leopard through expanding habitat availability and increased divesity availability of prey animals. In view of the value of game, especially rare game species, losses due to predators are often viewed by land owners in a more serious light than stock losses. This has led to increased prosecution of predators such as the leopard. In an attempt to address the conflict between predators and game- and livestock farmers, a research project on leopards was initiated in the Limpompo Province, South Africa (Smit 2002; Van Wyk 2003). As part of this larger research project, the need has arisen to be able to identify the remains of mammal prey species in the feaces of leopards. A list of fourty expected prey mammal species that potentially occur in the northern savanna areas of South Africa was compiled. They covered a broad range of families, namely bovidae, viverridae, procaviidae, mustelidae, gliridae, muridae, suidae, leporidae, orycteropodidae, sciuridae, felinae, cercopithecidae and thryonomyidae. The objectives of this study were to prepare hair samples from these selected mammal species for microscopic analyses with a view to obtain detailed illustrations of the cuticular scale patterns and cross-sections of the hair, to study and describe the taxonomic features of the hair of the various mammal species and to compile a key that can assist with the identification of these mammal species from microscopic analyses of hair samples. Hair samples were taken from the dried skins of specimens of the selected mammal species that were hosted in the Transvaal Museum in Pretoria. A study was also conducted to determine if the characteristics of hair from distinctly different body parts of mammals differ. The impala was selected for this study in view of its importance as a preferred prey species of the leopard in the northern savanna of South Africa. Hair samples for this study were obtained from a fresh impala carcass. After preparation of the hair samples, the cuticular scale patterns were photographed using a scanning electron microscope. Cross-sections of the hair were photographed with a Nikon light microscope. In this study, mainly the guard hair of the mammal species were considered for study since they showed the most distinct variation in shape and characteristics. The four features of hair morphology that were considered the most important for identification, are the cuticular scale patterns, the cross-section shape of the hair itself, the cortex and medulla. The colour of the hair and the appearance and distribution of the pigments can sometimes serve as aids to identification and in this study pigmentation was considered in the description of the cross-section of the hair. The hair of the impala taken from the different body parts varied in colour. Microscopic examination of hair structure from the different body parts revealed a number of differences namely the cross-section shapes, diameter of hair and the pigmetation of the cortex, but the scale patterns of hair from the different hair body parts were found to be very similar. The only exceptions were hair from the brisket and foreleg that differed from the hair of the rest of the body. A key using the taxonomic characteristics of the hair, was compiled to assist in the identification of the thirty-nine mammal species. Since the key does not always key out on individual species, it is recommended that the key only be used to narrow down the number of possible species. For the final identification the detailed description of the hair must be consulted

[发布机构] University of the Free State