Project Database

Abstract:

The endangered giant root-rat (Tachyoryctes macrocephalus, also known as giant mole rat) is a fossorial rodent endemic to the afro-alpine grasslands of the Bale Mountains in Ethiopia. The species is an important ecosystem engineer with the majority of the global population found within 1000 km2. Here, we present the first complete mitochondrial genome of the giant root-rat and the genus Tachyoryctes, recovered using shotgun sequencing and iterative mapping. A phylogenetic analysis including 15 other representatives of the family Spalacidae placed Tachyoryctes as sister genus to Rhizomys with high support. This position is in accordance with a recent study revealing the topology of the Spalacidae family. The full mitochondrial genome of the giant root-rat presents an important resource for further population genetic studies.

Abstract:

Aim: One objective was to quantify the impact of the Giant Mole Rat (Tachyoryctes macrocephalus) on vegetation communities and their composition. A second objective was to assess plant biomass (plant volume) via photography at the Sanetti Plateau. Third objective was to assess spatial distribution of the Giant Mole Rat across the Bale Mountains. In order to do that a predictive model has been applied. Location: Bale Mountains in south-eastern Ethiopia. Taxon: Tachyoryctes macrocephalus (Spalacideae). The species is related to other rats in eastern Africa and endemic to the Bale Mountains. Methods: The vegetation was sampled using a paired plot design along a transect from the southern to the northern rim of Sanetti Plateau and at sites where Giant Mole Rats were most abundant. Therefore, a total of 94 plots were established, 47 on Giant Mole Rat mounds and 47 in the zonal vegetation as control plots. Species identification and vegetation cover was investigated and photographs taken for further analysis of plant biomass. GPS data of around 1200 Giant Mole Rat mounds were recorded in order to upscale points on a larger area and detect the distribution of the Giant Mole Rat across the Bale Mountains. For that purpose Sentinel-2 satellite data was used with spatial resolution of 10 m, using a Forward Feature Selection. Results: We found out that the Giant Mole Rat is distributed across the whole Afroalpine zone of the Bale Mountains. It concentrates on the northern part of the Sanetti Plateau, in Sodota and Morebawa in wet and swampy habitat structures. Giant Mole Rats cover an area of 8301,16 ha and an estimated population density of 22 individuals/ha via upscaling could be proved. The Giant Mole Rat provides advantages to plants that require mixed and heterogen soil characteristics. The genera of Alchemilla and Salvia are examples for that and could be found on a major part of the Giant Mole Rat mounds. The genus of Helichrysum is abundant in the normal vegetation pattern and is almost completely absent on the Mole mounds. The presence of Helichrysum causes higher plant volume in the normal vegetation, which is 1,7 times higher than on the Mole mounds. Main conclusions: Giant Mole Rats change habitat and plant community structures. Shrub or woody plants do not occur on Giant Mole Rat mounds. The Giant Mole Rat is distributed across the whole Sanetti but most abundant in the northern part of Sanetti, Sodota and Morebawa. It prefers wet and swampy habitat.

Abstract:

Studies of early human settlement in alpine environments provide insights into human physiological, genetic, and cultural adaptation potentials. Although Late and even Middle Pleistocene human presence has been recently documented on the Tibetan Plateau, little is known regarding the nature and context of early persistent human settlement in high elevations. Here, we report the earliest evidence of a prehistoric high-altitude residential site. Located in Africa’s largest alpine ecosystem, the repeated occupation of Fincha Habera rock shelter is dated to 47 to 31 thousand years ago.The available resources in cold and glaciated environments included the exploitation of an endemic rodent as a key food source, and this played a pivotal role in facilitating the occupation of this site by Late Pleistocene hunter-gatherers.