This led to eggshell thinning and breaking, which caused a dramatic decline in osprey populations by the 1970s. Ospreys, at the top of the aquatic food chain, accumulated large amounts of DDE, the chemical that DDT breaks down to in the environment, in their bodies. Widespread applications of the pesticide DDT over the 1950s and 1960s, led to its pervasive presence in the environment. Ospreys became a species of concern for conservationists across the nation and in Oregon during the 1970s. Female osprey only lay once a year, with one to four eggs in their clutch. Ospreys mate for life and return to the same nest each year. While in Oregon, osprey mate, nest, and raise their young until their first migratory flight. They come to Oregon in April and remain until September when they travel south for the winter, commonly to Mexico. Osprey also have a distinguishing dark stripe that runs along their eye down the side of their white face. Most notably, osprey have a white underbelly, visible while they soar through the air. Osprey are often mistaken for eagles, but osprey possess distinct markings. They rely on tall snags, dead standing trees, to make their nests. Osprey make their homes along lakes, reservoirs, large rivers, and estuaries. Skilled artists in the air, ospreys can be seen diving into water bodies from heights of 30 to 100 feet to snag fish, which comprise 99% of these raptors' diets.

Osprey wingspan