Bald eagles are found in and near desert, mountain, freshwater, and marine environments throughout the United States. Bald eagles build huge nests that are usually in treetops, near areas of water. The main food source for bald eagles is fish, but the birds sometimes eat other small animals. In 1967, the bald eagle was listed as an endangered species by the Environmental Protection Agency. The widespread use of DDT was responsible for the decline in the number of eagles. DDT, a chemical commonly used to control mosquitoes, caused thinning of the eagle egg shells.

The data table below shows how the population of breeding pairs of bald eagles has changed over a 12-year period in several states.

Which statement is the most likely reason for the large difference in the number of breeding pairs in Maryland and Nevada?

1. There are fewer trees in Maryland.
2. There are more fish in Nevada.
3. There are more open waters in Maryland.
4. There are fewer small animals in Nevada.

Bald eagles are found in and near desert, mountain, freshwater, and marine environments throughout the United States. Bald eagles build huge nests that are usually in treetops, near areas of water. The main food source for bald eagles is fish, but the birds sometimes eat other small animals. In 1967, the bald eagle was listed as an endangered species by the Environmental Protection Agency. The widespread use of DDT was responsible for the decline in the number of eagles. DDT, a chemical commonly used to control mosquitoes, caused thinning of the eagle egg shells.

The data table below shows how the population of breeding pairs of bald eagles has changed over a 12-year period in several states.

Which statement best explains why habitats in Michigan and Maryland support more breeding pairs than habitats in other states?

1. Cropland provides grain for food.
2. Large lakes and rivers provide food.
3. Mountains provide fewer places to hunt.
4. Grasslands provide homes for large animals.