Conditions and changing capacity. Regional data for North America document marked declines in grassland bird species and classify 10-20 percent of grassland plant species in some areas as nonnative. In other areas, such as the Serengeti in Africa, there are steady long-term population trends for large grassland herbivores.

Data quality. Long-term trends in grassland bird populations can be assessed from comprehensive regional data for the United States and Canada. Some long-term regional data within Africa show steady levels of major herbivore populations, but geographic coverage is limited. Other regional, national, and local data for grassland species lack long-term trends. Regional and local coverage of invasive species are more descriptive than quantitative.