Management & Land-Use Effects
Grassland Grazing
The idea –
There is general agreement that some grassland bird species are declining and, as a group, harbor a disproportionately large number of species in decline. The best documented problems facing grassland birds are the loss of native prairie habitat due to habitat conversion for agricultural purposes, but there may also be problems associated with range degradation as a result of fire suppression and livestock grazing. Because grassland structure is affected significantly by grazing intensity, we sought to understand the relationship between grassland vegetation height and thickness and landbird community composition.
Methods –
Within the Little Missouri National Grasslands, we placed eight 10-point transects in each of three interspersed classes of grassland height: (1) short (< 0.5 dm tall), (2) moderately tall (0.5-1.0 dm tall), and (3) tall (>1.0 dm tall).
Results –
We detected 51 bird species within 100 m of the sample points during counts, but we chose to focus on 11 species that had over 35 detections in grassland habitat; each was present on at least 19 points. It became clear that some species responded significantly positively and others negatively to grassland height and density. Thus, no single structural target will satisfy the needs of all species and considerable variability in height of grasslands is needed to maintain conditions for species that have evolved in close association with the grassland vegetation type. Grassland managers should be moving toward attempts to mimic the natural processes (especially grazing and fire) that would have given rise to spatial variation in grassland height.
Annual Reports for this project –
Click here to download our Grassland Grazing report.
Funders –
USDA Forest Service Northern Region