Tb (open circles) and Ta (solid circles) and fitted cosine curves for a Cape ground squirrel during the 9th week of the sampling period illustrating the variation in Ta and Tb.

The difference between the lowest Tb value recorded (33.39°C at 19:08) and the highest Tb during the previous day (39.32°C at 16:08) was 5.93°C. Over the 23 week period, extreme changes in Tb included one individual that decreased in Tb by 5.56°C and another that increased in Tb by 5.98°C in one hour.