What is a common feature of immature Peregrine Falcons in Northeastern America?

Immature Peregrine Falcons in Northeastern America are typically identified by their distinctive plumage, which often showcases shades of rich reddish-brown. This coloration is a key characteristic that can help in identifying the age and developmental stage of the bird. The darker, more camouflaging plumage serves as an adaptation for younger birds, as it provides some concealment in their natural habitats while they are learning to hunt and survive independently. The reddish-brown shades contrast with the adult birds, which possess the more familiar slate-blue plumage with cream-colored underparts.

The other features mentioned, such as being lighter in weight, being more aggressive, or migrating earlier, do not accurately represent the common traits of immature Peregrine Falcons during this developmental stage. While behavior and migration patterns can vary among individual birds or in different environmental conditions, the plumage coloration is a consistent and identifiable feature for these immature falcons.