A common question about bald eagles is whether females are brown. Their appearance changes significantly with age, not sex. Understanding these age-related plumage variations is key to accurate identification in the wild.
The Distinct Look of Adult Bald Eagles
Adult bald eagles have an easily recognizable appearance. Their bodies and wings are dark brown, contrasting sharply with pure white heads and tails. Their large, hooked beaks, feet, and irises are yellow. This plumage is characteristic of both male and female bald eagles once they reach maturity, a process that takes several years.
Are Female Bald Eagles Different?
Coloration is not a reliable indicator for distinguishing male and female bald eagles. Both sexes display the same adult plumage. The primary difference is size: females are generally larger and heavier than males, typically weighing about 25% more. For example, a female may average around 12 pounds, while a male might weigh closer to 9 pounds, though these figures vary by geographic location. This size disparity may not always be obvious unless observed side-by-side.
The “Brown” Truth: Juvenile Bald Eagles
The common perception of “brown” bald eagles largely stems from the appearance of juvenile, or immature, birds. Unlike adults, young bald eagles are predominantly dark brown, lacking the crisp white head and tail. Their plumage often appears mottled brown, with varying amounts of white flecking on their bodies and undersides of their wings.
Initially, their beaks are dark, and their eyes are brown, gradually lightening as they mature. As they progress through their first few years, they undergo several molts, gradually acquiring more white feathers on their head and tail. This transition can take between four to five years, with some individuals taking up to eight years to achieve full adult plumage. During this period, their appearance can be quite variable, making age identification challenging at times.
Identifying Bald Eagles: Avoiding Misidentification
Distinguishing bald eagles, especially juveniles, from other large birds of prey requires attention to multiple features. Juvenile bald eagles can sometimes be mistaken for golden eagles due to their overall brown coloration. However, bald eagles typically have a larger, more protruding head and a heavier, hooked bill compared to golden eagles.
In flight, bald eagles generally hold their broad wings flat, unlike some other raptors that hold them in a slight dihedral (V-shape). Observing the gradual progression of plumage from mottled brown to the classic white head and tail, along with changes in beak and eye color, helps confirm a bald eagle’s identity at various life stages. Focusing on these combined characteristics provides more accurate identification than relying solely on overall color.