American kestrels are known for their sexual dimorphism, which means that males and females have distinct differences in their plumage coloration. Male kestrels typically have a slate-blue back and a reddish-brown, streaked crown. In contrast, females usually have more brown and rufous coloring with a more uniform appearance. This visual distinction between the sexes is a key characteristic of the species and aids in identification.
Understanding the traits of American kestrels, such as their size and markings, is crucial for falconers and bird watchers. They are small raptors, not the largest, which is an important aspect that differentiates them from other raptors. Furthermore, they do possess distinctive markings, including facial markings that help in identification, emphasizing the importance of recognizing these features in the field.