We knew from other studies that Bald Eagles in the Chesapeake Bay eat mostly fish in the spring and summer months. But what kinds of fish are the eagles eating? Do Bald Eagles nesting in different areas in the Chesapeake Bay have different diets?

In an estuary like the Chesapeake Bay, salinity (the concentration of salt in water) varies. Some parts of the Bay are freshwater zones where the water's salinity is very low; other areas are more like the ocean where the salinity is very high. These changes in salinity are important to the fish living in the Bay waters. Different types of fish prefer different salinity zones. Some fish live mostly in freshwater while others mostly live in saltwater.

One of the questions we were curious about was whether or not the diet of Bald Eagles nesting close to low salinity water would be different than the diet of eagles nesting close to higher salinity water. Before you read on, stop and think about what you'd expect to find. Do you think the diet will differ?

Why is this question important? It is important for conservationists and wildlife managers to understand what resources the Bald Eagles are using. Part of this understanding comes from knowing what specific foods the eagles eat and whether or not the diet varies at different nests throughout the Chesapeake Bay. With this knowledge, we can protect not just the birds but also the plants and animals they depend on for nesting and food.