What is the best way to determine the sex of a raptor?

Determining the sex of a raptor is most effectively achieved through size differences, a method commonly known as sexual dimorphism. In many raptor species, females are significantly larger than males. This size disparity can be seen in various physical measurements such as wingspan, weight, and overall body length. For instance, in species like the Red-tailed Hawk, females can weigh as much as 30% more than males.

While the color of plumage can occasionally indicate sex in some species, it is not a reliable or universal method across all raptors. Behavioral traits can provide clues about mating or nesting roles, but they do not provide a definitive way to ascertain sex. Eye color also tends to vary due to age and can differ within the same species without indicating sex. Therefore, the best approach remains assessing the size differences between the male and female raptors.