Northern Prairie Wildlife Research Center
Fire is an important tool for creating landscape heterogeneity, controlling woody vegetation, reducing litter build-up, and increasing grass and forb production and diversity. To best benefit birds, burns should be scheduled before the breeding season and in the fall (Sample and Mossman 1997). Burning for livestock forage management in the Flint Hills usually occurs in April, when early nests of greater prairie-chickens and mourning doves will be destroyed (Zimmerman 1997). Rotational burning, every 2 to 5 years with variable frequency and seasonality is considered best for promoting diverse grasslands, and best mimics historic burn cycles (Heibert 1998). Yearly, same season burning decreases landscape and plant species diversity and discourages bird species that require residual vegetation (Sample and Mossman 1997, Heibert 1998). However, individual bird species differ in their tolerance for burned areas with some birds responding positively to newly burned sites while other species can not tolerate areas after burning (Herkert 1993, Sample and Mossman 1997, Johnson and Igl 1999). For example, management practices that favor Henslow's sparrows may not be optimal for grasshopper sparrows and dickcissels, but Henslow's sparrows are much more rare (Swengel 1996).
Grazing can also be used to create landscape heterogeneity, control woody plant species, reduce litter build-up, and reduce vegetation height and density, and often results in greater vegetation diversity than burning (Sample and Mossman 1997). Areas should not be heavily grazed, however, because heavily grazed areas rarely provide adequate nesting habitat for bird species of management concern (Sample and Mossman 1997). Grazing depresses the numbers of grassland-dependent birds, however, when combined with burning regimes (Zimmerman 1997). Most bird species respond best to light grazing intensities with a rotation grazing regime in which some sections are grazed while others are left ungrazed (Herkert 1993). Leaving some areas unburned and ungrazed for several years will also promote grazing and burning intolerant prairie species such as Henslow's sparrows and sedge wrens (Johnson and Igl 1999). If possible, areas should be left ungrazed until late in the nesting season and grazing should be discontinued soon enough in the fall to allow vegetation regrowth before dormancy (Sample and Mossman 1997).
Finally, many grassland-dependent bird species are area sensitive. Management practices that affect patches of continuous prairie habitat, including grazing and burning, should be planned in such a way that large enough areas are created to support breeding birds. For example, dickcissels and Henslow's sparrows are more abundant in larger prairies (Herkert 1994, Swengel 1996). TAPR is already divided into large pastures, separated by fencing. This partitioning is ideal for applying different management regimes to large areas to create a mosaic of habitats within TAPR. For example, each pasture could be burned on a different rotational scheme in different years.
We believe that it is important for the TAPR to continue a long-term bird monitoring because it will allow managers to assess the response of bird populations to changes in land-management. Future monitoring needs to include additional methods to inventory and monitor greater prairie chickens, raptors, swallows, and nightjars at TAPR. Finally, future research should also assess the impacts of grazing and burning on reproductive success of selected avian species at TAPR.