January-February 2020 • Nebraskaland 41
Wallowing
Bison also create important smaller-scale disturbances.
The most recognized of these is the result of wallowing, or
dust bathing. Whether to help shed a winter coat of fur or
gain some relief from fl ies and other biting insects, bison
enjoy rolling in the dust. Big bulls will also urinate and then
roll around in it to advertise their physical prowess to other
bulls. Over time, the favorite areas for these behaviors turn
into shallow depressions in the ground called wallows.
Bison wallows are utilized by other animals, too. Insects
are drawn to the open sunny habitats within wallows, and
that draws invertebrate predators including tiger beetles and
robber fl ies, as well as small vertebrates like toads, lizards
and rodents. Wallows also provide great habitat for plant
species that thrive in mostly bare soil where competition is
light. When wallows are temporarily abandoned as herds
move elsewhere, opportunistic plants quickly colonize them,
followed more slowly by longer-lived plants. However, when
fi re or chance brings the herds back, bison revisit previous
wallowing areas, re-opening and enlarging them each time.
When wallows are created in low-lying areas, or in soils that
are easily compacted, they can become temporary ponds after
rain events. Tadpoles of toads and frogs are often abundant
in those pools, along with aquatic insects and other small
animals. The ponds also provide drinking water to many
Fourpoint evening primrose is a biennial plant, and one of many plants that benefi ts from intensive bison grazing.
Lesser earless lizards are among numerous wildlife species
that appreciate habitat with a lot of exposed bare soil.
