Female bald eagles do not have white heads like their male counterparts. Instead, they have brown feathers on their heads and necks, with some white feathers mixed in. This is one of the primary differences between male and female bald eagles and is referred to as sexual dimorphism.
Scientific studies and observations have confirmed this difference in plumage between male and female bald eagles.
For example, a study published in the Journal of Raptor Research in 2007 found that only 30% of adult female bald eagles had fully white heads, compared to 90% of adult males.
Additionally, researchers have noted that young bald eagles of both sexes have brown heads and necks, with white feathers gradually replacing the brown as they mature.
Overall, while female bald eagles do not have white heads, they are still recognizable by their distinctive brown plumage and impressive size. As apex predators, bald eagles play a vital role in many ecosystems and are protected by numerous conservation efforts in the United States and Canada.
Differences Between Female And Male Bald Eagles
The primary difference between female and male Bald Eagles’ heads is their plumage. Male Bald Eagles have fully white heads and necks, while female Bald Eagles have brown feathers on their heads and necks with some white feathers mixed in.
This difference in plumage is known as sexual dimorphism and is thought to play a role in courtship and pair bonding. Additionally, male Bald Eagles have slightly smaller beaks than females.
|Characteristics||Female Bald Eagle||Male Bald Eagle|
|Size||Larger with a wingspan up to 7 feet||Smaller with a wingspan up to 6 feet|
|Weight||Heavier, averaging around 14 pounds||Lighter, averaging around 10 pounds|
|Plumage||Brown feathers on the head and neck with some white mixed in||Fully white head and neck|
|Beak||Slightly deeper and larger||Slightly smaller|
|Vocalization||Deeper and more guttural||Higher pitched and more shrill|
When Do Bald Eagle’s Heads Turn White
Bald Eagles’ heads typically start turning white between the ages of four and five years old. Young Bald Eagles have mostly brown plumage on their head and neck, with some white feathers mixed in. As they mature, the brown feathers gradually give way to white, and by the time they are four or five years old, their heads are typically fully white.
However, some Bald Eagles may retain some brown feathers on their heads even as adults, especially females who have a higher percentage of brown feathers compared to males.
The process of feather replacement is gradual and can take up to several years to complete, but eventually, both male and female Bald Eagles will have mostly white heads.
Do All Eagles Have White Heads?
No, not all eagles have white heads. While the Bald Eagle is the most well-known eagle species with a white head, other species of eagles have different plumage patterns. Here are some examples:
Golden Eagles: These eagles have dark brown plumage on their heads and necks, with a golden-colored nape. Juvenile Golden Eagles have lighter plumage on their heads that gradually darkens as they mature.
Harpy Eagles: These eagles have a distinctive grayish-white facial disk, but their heads are mostly black with a crest of feathers on top.
Philippine Eagles: These eagles have a bluish-grey coloration on their heads and necks, with shaggy, light-colored feathers around the eyes.
African Fish Eagles: These eagles have dark brown plumage on their heads and necks, with a distinctive white foreheads.
White-tailed Eagles: These eagles have mostly brown plumage on their heads and necks, with some white feathers mixed in. Juvenile White-tailed Eagles have more mottled plumage on their heads.
These different plumage patterns are a result of genetic and environmental factors that vary among eagle species. For example, the white head of the Bald Eagle is thought to be an adaptation for thermoregulation in cold northern climates.