Cape Ground Squirrel

The Cape ground squirrel (Xerus inauris) lives in the hot, dry Kalahari region of southern Africa. Unlike many desert mammals it is active during the day, foraging for seeds, roots and bulbs when surface temperatures are very high. It uses a combination of behaviour and anatomy to avoid overheating.The tail as a parasol. Its long, bushy tail is held arched over its back and head, like a sunshade. This shades the body, reducing the heat it gains from the Sun by radiation, so the squirrel can stay out foraging for longer before it overheats.Burrows as heat sinks. It lives in burrows, where the air and soil are much cooler than at the surface. When its body temperature rises during foraging, it returns to the burrow and lies on the cool soil, losing heat by conduction, and then comes out again. This pattern of heating up outside and cooling down underground can be repeated many times through the day.Water. It gets most of the water it needs from its food, so it rarely needs to drink. Because shade and burrows do most of the cooling, it loses little water by panting or sweating.Applying the ideas. The squirrel shows that behavioural adaptations can let an endotherm stay active in a very hot environment while saving water. It also shows a trade-off: time in the burrow is time not spent feeding, and the tail lets it reduce that time.