Bald eagles are one of the most popular birds in North America. They are known for their impressive size, beautiful plumage, and strong beaks. Their majestic appearance and size make them stand out in the bird kingdom. And also, the bald eagle was designated as the national bird of the United States in 1782.
The most identifiable features of bald eagles are white heads, brown bodies, and an 8-foot wingspan. From them, the most fascinating feature of the bald eagle for me is the white head.
It gives them the majestic look. Isn’t it?
So, if you are interested (like me) in learning more about bald eagles, then, probably you may have the question, “Why do bald eagles have white head plumage?” Let’s find out why.
Why Do Bald Eagles Have White Heads?
Scientists and experts have not clearly expressed why the bald eagle’s head turns white. However, few activists have given their opinions on the matter as follows,
- Opinion 1 – White head is an attractor to find a mate: I personally believe this can be the most promising reason since bald eagle head turns white when they reach sexual maturity. Therefore, it can be one of the indicators of their sexual maturity to their mate.
- Opinion 2 – White plumage on the head in adults helps them to camouflage in the sky: Well, this can be true to dark color juvenile eagles since they can survive in darker environments such as in nests or woods and avoid any trouble. However, since adults are having darker bodies (brown with creamy mocha-infused color) and white head plumage, and dirty white tails, it is hard to believe they can camouflage well in the sky.
- Opinion 3 – It helps to convey the presence of the bald eagle to other eagles or predators: As the white head is the most distinguishable feature of the bald eagle to separate them from other similar species, this opinion has some weight too.
- Opinion 4 – White plumage in the head helps to keep the bald eagle’s head cooler when it is exposed to the sun: Overheating can be a health risk to birds. Since white surfaces reflect more light than darker surfaces, white feathers may help to keep the temperature down in the head. But what about the body? This opinion fails the logic with darker body plumage in bald eagles.
So, as you can see, there are numerous opinions given on the topic. Out of them, I’ll go with the first listed one which is “White head helps bald eagles to get the attention of their mates and attract them”.
When Do Bald Eagles Get White Heads?
Most bald eagles get pure white heads when they are 5.5 years old. However, some may get it a little sooner (in 4.5 years) and for some, it takes a longer time such as 8 years.
So, you might wonder how they look like before they become mature. Here are some details about them during their transition from eaglet to an adult.
Age | Appearance |
1-12 weeks (Nestlings) | When hatching, eaglets are light grey white on the head and neck. In 3-4 weeks, their plumage becomes darker where black contoured feathers start to grow especially in the back, breast, and wings. They are fully grown when they reach about 9 weeks and are strong enough to leave the nest in 12 weeks. |
12 weeks to 1.5 years | Juveniles have fully grown dark brown plumage with white flecking here and there. And in the first year to year and a half, their plumage color does not change much except having about 2 molting cycles. After about 6 six months of leaving the nest, the bald eagle starts to turn light brown, and in 1.5 years of age, white flecking under wings is more apparent and clearly visible in flight. And its bill color is dark grey and for some juveniles, the bill starts coloring when it is 1.5-year old. |
1.5 – 2.5 years | At this age, plumage is very variable which makes it difficult to predict their age. Some may be majorly darker in color with white flecking while others may have mostly white plumage with brown flecking. At around 2-3 years of age, their bills turn yellowish-brown. The most identifiable feature during this age is having a contrasting breast color (dark brown) with throat and belly which have a much paler color. |
2.5 – 3.5 years | At this stage, the bald eagle’s head and tail start turning white. But they are mostly decorated with brown flecking. This indicates the transition stage from young to adult. They have mostly yellow bills and their belly starts darkening with brown body plumage. In-flight, they look alike adults, except adults have white heads and tails. |
4.5 – Adult | During this time period, bald eagles undergo a complete transition to the adult. They get fully grown adult plumage with pure white head and tail. Adults have bright yellow bill and legs and their eyes look yellowish white. Once it has fully grown into an adult, this appearance remains the rest of the time. |
So, juvenile bald eagles do not have pure white heads or tails. However, when they are around 3 years, their head and tail start turning white and get the clean white color at around 5.5 years when they become adults.
Do Female Bald Eagles Have White Heads?
Yes. female bald eagles also have white heads. Both male and female adult bald eagles look alike. They both have white heads and tails, dark brown bodies, bright yellow bills, and legs. So, if you see a single bald eagle in the field, it is hard to tell exactly whether it is a male or female.
However, there are a few differences that may help to distinguish female bald eagles from males.
Size:
However, size and weight is not the best separation factor between male and female bald eagles. For example, the largest northern male eagle may be as big or bigger than the smallest southern female eagle.
Females are comparatively larger in size than their male counterparts. The female bald eagle is about a third larger than males. And female bald eagles are about three inches lengthier and about 30% heavier. Hence, this may help to separate the male and female if you see a pair.
Voice:
Male’s call is higher in pitch than females. However, this difference is subtle so we (humans) need special tools to notice it clearly.
However, a surgical examination or a DNA test would be the only 100% accurate methods to distinguish between male and female bald eagles.
What Birds (Other Than Bald Eagle) Have White Heads?
If you ask the question “what birds have the white heads?”, there are a number of bird species that comes to my mind. Several species of gulls, egrets, terns, and snowy owls are a few of the white-headed bird species.
However, if we check which birds of prey have white heads, the bald eagle is the most obvious one.
Are There Eagles (Other Than Bald Eagle) with white heads?
Other than the bald eagle, you will only spot one other eagle species in North America, that is “golden eagle”. Since the golden eagle has a brown head with golden nape, you will not find any eagle with a white head in north America.
But, are there any eagles other than bald eagle with white heads? Yes, there are several eagle species with white heads in other regions of the world. Following are a few of them.
White-bellied Sea-Eagle
This bird of prey is very common to see in coastal and near coastal areas in Australia. It has a white head and underparts, black flight feathers, a grey bill, and dark brown eyes. It is the second-largest raptor in Australia.
African Fish-Eagle
As the name indicates, African Fish-Eagle can be found throughout sub-Saharan Africa near rivers and lakes, and other large water bodies. And it is also called African Sea-Eagle.
Similar to the Bald Eagle, African Fish-Eagle also has a snow-white head and tail. In addition, its breast is also white and its body and wings are brown. And, it has a featherless yellow face which is quite unique.
Black-and-white Hawk-Eagle
Bland-and-white Hawk Eagles are very distinctive medium size raptors. They have white head with black short crest, orange-yellow base of bill, black patch around the eyes.
Its range spans from southern Mexico to northern Argentina covering a large part of the Neotropical region.
Are eagles the only raptor with a white head?
Eagles are not the only raptor with white heads. White-tailed Kite, Western Osprey, Swallow-tailed Kite, Mississippi Kite and krider’s red-tailed hawk are several white-headed raptors that can be found in north America.
In addition, there are number of other raptors such as white hawk and brahminy kite which can be seen outside America that have white heads too.
FAQs About Bald Eagles
Do juvenile bald eagle look similar to the golden eagle?
Bald eagles and golden eagles have lot of similarities. They are about same size and have dark colored bodies. But, pure white head of adult bald eagle makes it easy for us to distinguish between two species.
However, juvenile bald eagles have all dark head and it can be easily confused with golden eagles whose heads are also dark brown.
So, is there ways for us to distingush them? Yes, one fo the differences is, feathers cover legs of golden eagle upto its feet while bald eagles have unfeathered legs.
Do bald eagles mate for life?
Yes, bald eagles are monogamous and mate for life. Once they find their mate in the first breading season, they stay loyal to that mate for the rest of the life. They only find another mate if the first mate has died or lost due to any other reason.
Conclusion
In this article, we discussed number of facinating facts about pure white head of bald eagle which is the most glamorous feature of it.
There are several opinions given on why bald eagle’s head is white. Out of them, “white head helps to indicate the sexual maturity and attract mates” seems more logical opinion. Bald eagle’s head turns pure white when they reach the age of about 5 years (at sexual maturity).
Before turning white, juvenile bald eagles have darker heads which causes misidentification of them with golden eagles.