This can be a lethal difference for a small animal exposed on the soil surface. Of course not all soil is exposed to the sun and even the sparse shade of a gum tree will help reduce the temperature on the ground below. The dense shade cast by cypress pine and wilga cuts the temperature dramatically. The larger animals such as kangaroos and wallaroos cant find kangaroo sized holes but will be found lounging in the shade of suitable trees. Sometimes you will see depressions where the ,roos have scraped aside the hotter topsoil to lay on the cooler earth below.
Rock wallabies live in a very demanding environment of bare rock, sparse herbage and limited water.
These animals are ultimately dependent on caves for survival. Without shelter from the sun in the hottest part of the day these beautiful little wallabies would have to rely on evaporative cooling, using their body water, to keep their temperature under control. Evaporative cooling is OK if you have an adequate water supply but the rock wallabies have no such luxury. In the hotter inland goats take over the caves and the rock wallabies decline in numbers as they are excluded from the life sustaining shelter. The colour of the soil itself influences the temperature it reaches after a few hours exposure to the summer sun.