Which falcon's immature plumage is very similar to its mature plumage?

The American Kestrel's immature plumage bears a striking resemblance to its mature plumage, which sets it apart from many other falcon species that exhibit significant changes in coloration as they mature. This similarity in plumage helps in recognizing the species at different life stages, making identification more straightforward. Immature kestrels typically retain much of the coloration and patterns seen in adults, such as the distinctive rufous and gray markings, allowing for easier field identification by birdwatchers and falconers alike.

In contrast, species like the Peregrine Falcon and Gyrfalcon undergo more pronounced changes from juvenile to adult stages, with their immature feathers being distinct from their mature counterparts. Understanding these variations is essential for individuals studying falconry or bird identification.