The vegetation in a grassland ecosystem consists mainly of grasses, shrubs, and bushes. The prairie dog is a small rodent that grazes on the grasses found in the North American grasslands. The swift fox feeds on the prairie dog, and is in turn preyed upon by the badger. The golden eagle feeds on the badger. The following graph shows a decline in the population of the golden eagle over a span of five years, due to a disease that affected the golden eagle population.