How can the sex of most North American raptors be most easily determined?

The sex of most North American raptors can most easily be determined by size. In many raptor species, females are larger than males, a phenomenon known as sexual dimorphism. This size difference is particularly pronounced in species such as the Red-tailed Hawk and the Peregrine Falcon, where females can be considerably heavier and larger in wingspan compared to their male counterparts.

While coloration, beak shape, and vocalization patterns may also offer some clues in specific cases, relying on size is generally the most straightforward and consistent method across various species of raptors. Factors such as environmental influences and individual variation can often complicate the interpretation of coloration and beak shape, making size the more reliable indicator when trying to determine the sex of these birds in the field.