Behaviour

Apart from their foraging behaviour, bison influence their surroundings also in other respects. Bison often take sand baths and by doing so they create substantial open sandy patches. Locally, the wind gets hold of the sand again. Bison play a positive role towards a more dynamic the dune system. When a sandy spot is less used for a while, pioneer plant species, sand lizards and many insects get a chance. For instance sand wasps and mining bees who need bare sandy spots to dig their holes. Or tiger beetles that hunt for other insects on the bare sand.

Sand lizard. Photo: Leo Linnartz

As bison often take a sand bath and also like resting and ruminating on bare sand, these places get connected by an extensive network of paths. Due to the short grass or bare sand, these paths become a sort of hihgway for ground bettles and lizards to get from one convenient place to another. Edges of these routes as well as the sand baths are also suitable growth areas for pioneer plant species such as Carline thistle and houndstongue. And when your seeds easily stick to the fur of a passing bison, you get also a free ride to the next appropriate growth spot.

Some large trees are chosen to rub their fur against and to scent-mark their territory. Due to frequent rubbing the tree may lose its entire bark and will die. It will keep its function as rub and mark tree for a while, but in the end the trunk will rot through at the bottom and the bison will have to use another tree. The result is an open space, from which the plants on the ground will profit for some time.