Outside Influences

Climate Change
In the Pacific Northwest, global climate change models indicate that winter and summer temperatures in the region are likely to be warmer, with possibly higher amounts of winter precipitation. Poor weather conditions during winter or migration periods may force peregrines to switch to alternate prey or use less efficient hunting techniques, which can affect their overall fitness. Along the outer coast, reproductive success has been documented to be lower during years of warm oceanic conditions associated with El Nino episodes. Warmer, drier summers could result in changing hydrology, with potential contraction of wetlands and conversion of meadows to forest. This could affect both foraging opportunities and prey populations upon which peregrine falcons depend.
More information on the status of global climate change can be found on the US Global Change Research Program website.

Environmental Contaminants
Peregrine falcons 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 peregrine populations. These include heavy metals such as lead and mercury, PCBs, (polychlorinated biphenyls), dieldrin, heptachlor epoxide, and organophosphorus (OP) and carbamate pesticides.