Outside Influences

Loss of old-growth forest habitat on a landscape scale
Loss of the majority of low elevation old-growth forest habitat to development and other uses such as short-rotation timber production has greatly reduced the number of available large nesting trees and perching snags required by bald eagles.

Climate change
In the Pacific Northwest, global climate change models indicate that winter and summer temperatures in the region are likely to be warmer. Increased summer temperatures could result in a higher risk of forest fire, which could lead to loss of existing or developing nesting habitat. Warming temperatures could have a significant effect on thermal regimes in lakes and the amount and timing of spring runoff, both of which could negatively affect fish populations that are used as primary food sources for bald eagles. More information on the status of global climate change can be found on the US Global Change Research Program website.

Environmental contaminants
Bald eagles ingest and accumulate contaminants that are present in their prey. Although DDT has been banned, many other toxic chemicals still in use have the potential to adversely affect the eagle populations. These include heavy metals such as lead and mercury, PCBs, (polychlorinated biphenyls), dieldrin, heptachlor epoxide, and organophosphorus (OP) and carbamate pesticides.