The bald eagle is a majestic bird of prey and the national symbol of the United States. Bald eagles build massive nests high up in trees near waterways, where they raise their young. But after the eaglets fledge and leave the nest, how far do bald eagles travel? The answer depends on the age and life stage of the eagle.
Bald Eagle Nesting and Fledging
Bald eagles reach breeding maturity around 4-5 years old. They return to nest in the general area where they were born, building nests up to 10 feet wide and weighing over 1 ton! The nest is lined with soft materials like grass and feathers. The female lays 1-3 eggs in late winter or early spring. The eggs hatch after about 35 days of incubation.
Eaglets fledge (leave the nest) after 10-13 weeks, sometime between June and August. They are still dependent on their parents for food at this stage. Fledging is a dangerous time for juvenile bald eagles, with high mortality rates due to starvation, accidents, and conflicts with other eagles.
Juvenile bald eagles
After leaving the nest, juvenile bald eagles will stay relatively close to their parents’ territory for the first few months. They are learning to hunt and fend for themselves. Juveniles have mottled brown and white plumage, gradually acquiring the distinctive white head and tail of adults over 4-5 years.
Most juvenile bald eagles stay within 60-125 miles of their nest during the summer and fall after fledging. However, some have been recorded traveling much farther distances of 200+ miles. A juvenile tagged in Michigan traveled all the way to Missouri, over 500 miles from its nest!
Long-distance post-fledging dispersal may be more common than previously thought. A 2022 study tracked 17 juvenile bald eagles in Minnesota and Wisconsin via satellite. It found that juveniles traveled an average of 62 miles from the nest 8 weeks after fledging. But the farthest individual went 273 miles away.
Subadult bald eagles
In their second summer after hatching, bald eagles are considered subadults. They may start wandering farther from their natal areas at this stage. Average dispersal distances for subadult bald eagles are around 100 miles. But they are capable of traveling several hundred miles.
For example, a subadult bald eagle tagged in Georgia was later sighted on the shores of Hudson Bay in northern Canada! This epic journey was over 3000 miles one-way. Such long-distance dispersal is unusual but demonstrates the eagle’s flying capabilities.
Subadult bald eagles seem to explore new habitats and regions intentionally. Young eagles may be driven away from prime nesting areas by adult territorial pairs. Dispersing to new areas gives subadults a chance at securing their own breeding territories.
Adult bald eagle movements
Once bald eagles reach adulthood and establish breeding territories, they show high nesting site fidelity. Most adults return to the same nesting locale each year. However, eagles without fixed territories will range more widely.
Adult bald eagle home ranges are larger in the non-breeding season. Average home ranges span around 125 miles across. In Wyoming, the average home range size was 156 miles. And some individuals may cover thousands of square miles over a year.
Bald eagles that nest further inland make seasonal movements towards the coast during winter. They congregate near open water to feed on fish where inland lakes and rivers freeze. Banding recoveries show some adults fly 500 miles or more to reach wintering grounds.
Migration of northern bald eagles
Bald eagles from Alaska and Canada migrate long distances of 1000+ miles. They head south to escape harsh winters when their normal food sources become unavailable.
Eagles that breed along the northern Pacific Coast fly south to winter along the southern coast. Some go as far as Baja California, Mexico. Others follow river systems inland through the western states.
In the Midwest and Northeast, bald eagles migrate south in winter along lakeshores, coasts, and major river systems. Northern migrants mix with southern resident eagles along major waterways and wetlands.
Some northern bald eagles complete an elongated loop migration. They fly northeast in spring, following edges of retreating sea ice. Then they trace back southwest in fall, sometimes crossing the entire continent.
Notable bald eagle migration records
Here are some record-setting examples of bald eagle migration distances:
Bald eagle ID | Migration route | Distance |
---|---|---|
Alaska to Saskatchewan | North to south | 4000 miles |
Wisconsin to Nova Scotia | West to northeast loop | 5000 miles |
Florida to Michigan | South to north | 1200 miles |
These extreme long-distance migrations demonstrate the bald eagle’s flying capabilities. They can cover vast distances across North America throughout the year while searching for food, nesting sites, and wintering habitat.
Daily bald eagle movements
Within their home ranges, bald eagles commute daily between roosting and feeding areas. They typically roost overnight in large trees or on cliffs near water.
Bald eagles usually forage within a 6-12 mile radius of night roosts during the day. But they can and do travel farther to find food when necessary.
Studies in Alaska found average daily cruising flight distances of around 20 miles for breeding adults. Maximum foraging flights reached up to 48 miles from the nest to secure food. Non-breeding bald eagles range even more widely on a daily basis.
With their large wingspans of up to 7 feet, bald eagles are efficient soarers. They can ride thermals and updrafts to cover ground easily with minimal effort. Eagles have been recorded migrating at up to 35-44 mph when gliding aided by winds.
Why do bald eagles travel long distances?
Here are some of the main reasons bald eagles embark on long-distance journeys:
- Dispersal of juveniles away from crowded natal areas
- Searching for food and habitat during winter months
- Finding suitable nesting locations as they reach breeding age
- Expanding foraging range during the non-breeding season
- Temporarily relocating due to severe weather, storms, or fires
- Stopovers to rest and refuel during migration
Bald eagle movements are driven by a combination of genetically programmed urges and responses to environmental conditions. Their large ranges bring dispersed populations into contact, promoting genetic exchange.
Tracking bald eagle movements
Bald eagle migrations and ranges are studied through banding and tracking techniques:
- Leg bands – Uniquely numbered metal bands allow identification when eagles are recaptured or found deceased
- Wing tags – Large numbered tags are visible from a distance for resighting
- Satellite transmitters – Track GPS locations in near real-time from orbiting satellites
- GPS data loggers – Lightweight loggers record position data for downloading later
- Geolocators – Estimate locations from day length and time
Combining data from band recoveries, telemetry studies, and resightings gives detailed insights into bald eagle movements and behavior.
Bald eagle habitat use
Bald eagles occupy diverse habitats across North America based on regional ecology:
- Coastlines – Nest and forage at coastal edges with abundant fish
- Rivers – Key inland habitat with open water for fishing
- Lakes – Perch and fish in large lake systems
- Wetlands – Feed at marshes rich in waterfowl and small mammals
- Islands – Isolated islands provide safety for nesting
- Forests – Nest and roost in tall trees, hunt in open areas
- Mountains – Nests on cliffs and crags, thermal updrafts aid soaring
Bald eagles are opportunistic foragers. They move among various habitat patches to take advantage of seasonal food resources. Their extensive travels let them exploit resources across the landscape.
Threats from extensive movements
The bald eagle’s vast range and long-distance movements also expose it to numerous threats:
- Collisions with vehicles, planes, powerlines
- Poisoning from pesticides or lead ammunition
- Shooting and illegal hunting
- Habitat loss such as filling in wetlands
- Human disturbance of nest sites
- Changing climate patterns disrupting migration timing
Fortunately, bald eagle populations have rebounded following banning of DDT and Federal protections. But ongoing habitat conservation is crucial for maintaining mobile eagle populations.
Conclusion
Bald eagles are well known for their epic long-distance migrations and movements. Juveniles and subadults wander farther from their natal sites as they mature and search for territories. Adult eagles commute daily within expansive home ranges. And northern populations migrate thousands of miles seasonally.
Modern tracking studies continue revealing new insights into bald eagle movements. Protecting habitat corridors and resources across the landscape will allow bald eagles to continue their iconic migrations and range expansions into the future.