Home range and use of diurnal shelters by the Etendeka round-eared sengi a newly discovered Namibian endemic desert mammal

摘要

To understand habitat use by the newly described Etendeka round-eared sengi (Macroscelides micus) in northwestern Namibia, we radio-tracked five individuals for nearly a month. Home ranges (100% convex polygons) in the rocky desert habitat were remarkably large (mean 14.9 ha) when compared to sengi species in more mesic habitats (<1.5 ha). The activity pattern of M. micus was strictly nocturnal, which contrasts to the normal diurnal or crepuscular activity of other sengis. The day shelters of M. micus were under single rocks and they likely were occupied by single sengis. One tagged sengi used 22 different day shelters during the study. On average, only 7% of the day shelters were used more than once by the five tagged sengis. The shelters were also unusual for a small mammal in that they were unmodified in terms of excavation or nesting material. Shelter entrances were significantly oriented to face south by south west (average 193°), away from the angle of the prevailing midday sun. This suggests that solar radiation is probably an important aspect of M. micus thermal ecology, similar to other sengis. Compared to published data on other sengis, M. micus generally conforms to the unique sengi adaptive syndrome, but with modifications related to its hyper-arid habitat.