Eingang zum Volltext in OPUS
Hinweis zum Urheberrecht
Dissertation zugänglich unter
Elevational Distribution and Taxonomy of Shrews and Rodents in the Mountains of Northern Tanzania
Höhenverteilung und Taxonomie von Spitzmäusen und Nagetieren in den Bergen Nord- Tansanias
Stanley, William T.
Dokument 1.pdf (4.653 KB)
Ganzhorn, Jörg U. (Prof. Dr.)
Tag der mündlichen Prüfung:
Kurzfassung auf Englisch:
The ecology of the small mammals living on the mountains of Tanzania is poorly known. In particular, the distribution of species along elevational gradients on these massifs requires detailed surveys to adequately understand the relationship between species diversity and their altitudinal distribution. Two mountains in particular are notable in the paucity of specimen-based surveys that have been undertaken: Mt. Kilimanjaro, the highest mountain of Africa, and Mt. Meru, Tanzania’s second highest mountain. Here I document the distribution of shrews and rodents along an elevational gradient on the southeastern versant of these mountains. Five sites were sampled on each mountain, on Kilimanjaro between 2000 and 4000 m and on Meru between 1950 and 3600 m, using a systematic methodology of standard traps and pitfall lines, to inventory the shrews and rodents of the slopes. On Kilimanjaro, 16 species of small mammal were recorded, including six shrew and 10 rodent species, and the greatest diversity for both was found at 3000 m, the elevational midpoint of the transect. On Meru, 10 species of mammal were recorded, including two shrew (one of which is a new taxon) and eight rodent species, and the greatest diversity for both was found at 2300 m. All documented species were previously known from the two massifs. Two rodent genera that occur in the nearby Eastern Arc Mountains (Hylomyscus and Beamys), were not recorded on the two massifs. Species that are endemic to each mountain (Myosorex zinki-Kilimanjaro and Lophuromys verhageni-Meru) are widespread across the elevational gradient, and only absent from the lowest site on each gradient. As in other faunal surveys on other mountains of Tanzania using similar methodologies, rainfall influenced the sample success of shrews, but not rodents.
Mt. Kilimanjaro is the type locality for Crocidura monax Thomas, a crocidurine shrew for which the taxonomy and detailed distribution has been debated since its description. While some workers maintain that it is restricted to Kilimanjaro, others have suggested it occurs on neighboring montane islands. I assess morphological variation among isolated montane populations of C. monax from Tanzania that have been referred to C. monax. The montane sites used in this analysis are from two geologically distinct archipelagos (Northern Highlands and the Eastern Arc Mountains) and are a significant component of the Eastern Afromontane Biodiversity Hotspot. Multivariate analyses of morphometric traits suggest two undescribed shrews previously considered C. monax occur on these mountains, one on Ngorongoro and another shared by four Eastern Arc Mountains (Rubeho, Ukaguru, Uluguru, and Udzungwa). Similar cranial morphology indicates that C. monax is restricted to Mt. Kilimanjaro and North Pare, while C. tansaniana is found on the East and West Usambaras, and C. usambarae occurs on both the South Pares and the West Usambaras.