The ecophysiology of the Cape ground squirrel Xerus inauris

Abstract

Cape ground squirrels, Xerus inauris, are successful rodents of the southern African arid sub-region, living in burrows, exchanging the macro-climate for the micro-climate whenever the first becomes difficult. Several facets of their behaviour, thermoregulation, water balance and gut morphology were investigated and correlated with the climate and vegetation in the southern Kalahari. They are diurnal and live in social groups, raise altricial young, show signs of cooperative breeding, have female matriarchal systems and bachelor groups. The home range shapes were influenced by the dune topography of the study area. Although no specific evidence of gut specialization was found, they have a complex stomach, enlarged caecum and feed selectively on the most nutritious foodstuffs from a central place. The kidneys control water flux so that concentrated urine is excreted. X. inauris do not hibernate or estivate, but they do become hyperthermic during exposure to heat and show tendencies towards hypothermia when placed under low temperatures. Groups of squirrels huddle and bask during winter to counteract the cold, and during summer a parasol tail is used as a shading mechanism and excess heat is offloaded during sand bathing.