Bemidji, Minnesota Red Lake Elementary School Q: How can you tell the difference between a male and female adult bald eagle?
Visually, they look identical, but as with most raptors, the female is larger (heavier and bigger) than the male. Sometimes this is clearly visible in a pair, when you see both together at the nest, but otherwise, we are just guessing. In the hand, biologists can differentiate male versus female using two key body size measurements, the depth of the bill (beak) and the length of the hallux talon, on the rear toe. These measurements are plugged in to a neat formula developed by eagle biologist Gary Bortolotti back in the early 1980’s, based on numerous measurements of eagles of known sex.
