Nebraskaland

40 Nebraskaland • January-February 2020 fl ourished, including annual sunfl ower, ragweed, hoary vervain, evening primrose, gumweed and many others. The combination of short, weakened grasses and a fl ush of tall "weedy" wildfl owers created a habitat bonanza for many wildlife species. An abundance of insects quickly fl owed into those areas. Some, like bees and other pollinators, were drawn to the wealth of fl owers produced by the opportunistic plants. Other insects took advantage of a habitat structure that included tall wildfl owers with an understory of short grass plants, still weakened by a long period of repeated grazing. That combination made it easy for insects to regulate their temperature by moving quickly from sun to shade while feeding on the abundance of plants and/or other insects. Upland birds such as grouse and quail, looking for a place to rear their mobile broods, were drawn to the same locations. The chicks of those species could easily move through the short-statured grasses and feed on the abundant insects while sheltering under or near the protective cover of the "weedy" plants all around them. They could also easily fi nd sunny patches in the mornings to dry out and warm up and then enjoy the shade of tall wildfl owers during hot afternoons. As vegetation gradually recovered from the impacts of intense bison grazing, it became tall and dense once again. That provided habitat for yet another suite of wildlife species that preferred that heavier cover. Those species included nesting grouse and quail, along with other bird species such as sedge wrens and Henslow's sparrows. Some small mammal species, especially voles, also thrived in tall thatchy vegetation, and that, in turn, attracted predators like bull snakes and many others. Of course, the density of the plants and abundance of dried vegetation from previous years also created prime conditions for fi re, through either random lightning strikes or purposeful ignitions by people. Those fi res restarted the entire cycle of bison grazing and subsequent recovery. Today, grazing patterns of both bison and cattle can create a similar succession of habitat types across the prairie. However, most contemporary cattle management consists of relatively short bouts of grazing, which leads to quick recovery of grasses and low heterogeneity of vegetation heights and density across the landscape. Even many bison herds are managed in ways that fail to create the kinds of season-long intensive grazing that leads to fl ushes of opportunistic plants and the habitat they provide. As a result, many grasslands are missing some key habitat components, contributing to the plight of many wildlife species across the Great Plains. Dust bathing by bison creates wallows that provide habitat for many other animal and plant species.

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