Bald Eagles

The Bald Eagle (Haliaeetus leucocephalus) has been on the national seal of the United States since 1782 and a spiritual symbol for native people for far longer than that. A member of the genus Haliaeetus, or sea eagles, bald eagles will take a wide variety of prey but prefer fish and are usually found near water. Although Bald Eagles have a reputation as loners, they are very social off their territories and often form large communal roosts on their wintering grounds.

Most people are familiar with an adult bald eagle’s gleaming white head and tailfeathers and chocolate brown bodies and wings. However, Bald Eagles have three distinct subadult plumages that can vary widely in pattern and color. First-year eagles are brown, two to four-year-old eagles are streaked in shades of brown and white, and eagles older than five years old have white heads, white tailfeathers, and brown bodies and wings. Once endangered by hunting and pesticides, Bald Eagles have flourished under protection. In his 1987 book ‘The Bald Eagle’, researcher Mark Stalmaster mentions that most people would never have seen a Bald Eagle in its natural habitat. That is no longer true today: Bald Eagles are flourishing in Canada, the United States, and Northern Mexico.

Length: 27.9-37.8 in from beak to tail
(71-96 cm)
Weight: 105.8-222.2 oz
(3 to 6.300 kilograms)
Wingspan: 6.06 to 7.3 feet
80.3 in (204 cm)
Top Speed:
Close to 100 miles per hour
The oldest recorded wild Bald Eagle was 38 years old when it was hit by a car in 2015. In captivity, Bald Eagles can live to about 50 years of age, although most die younger.
Bald Eagles feed on a wide range of prey, but prefer fish. In our nests, fish compose about 70% of total prey, although fish species vary depending on location and seasonal availability. Bald Eagles might swoop down to catch live prey, steal prey from other birds (including bald eagles), or eat carrion. While Bald Eagles are renowned for their fishing and hunting prowess, it’s widely believed that carrion comprises a larger percentage of overall diet for young, inexperienced eagles who are learning the finer points of hunting and stealing.
The Raptor Resource Project Bald Eagle Tracking Project

Bald Eagle Range Map,

Bald Eagles breed across North America down into northern Mexico. Most eagles that nest in northern Canada migrate thousands of kilometers south to their wintering grounds, which includes the Driftless area of Iowa, Wisconsin, and Minnesota. Many non-territorial eagles in the United States migrate hundreds or thousands of kilometers north to summer in Canada.

The Raptor Resource Project began tracking fledglings from the Decorah Bald Eagles nest in 2011 to answer the question Where do the eagles go when they leave Decorah?”. We tracked nine eagles between August of 2011 and April of 2023. Of those nine:

  • Three were still alive when their transmitters failed
  • Three were electrocuted
  • Two were killed by cars
  • One died of lead poisoning after eating a lead slug embedded in game or carrion.

You can read our eagle tracking paper here: and explore the travels of the eagles through our interactive maps:

The Eagles we Tracked…
  • D1: Tracked July of 2011 to June of 2014
    Birthplace: N1, Decorah IA
    Parents: Mom and Dad | Sex: Female
    Last location: Hudson’s Bay, Ontario Canada [54.849, -82.198] D1 hatched in 2011. She summered on the west side of Hudson’s Bay and wintered near her birthplace in Decorah, Iowa. She was three years old when we lost contact with her. We don’t know what happened to her.
  • D14: Tracked July of 2012 to November of 2012
    Birthplace: N1, Decorah IA
    Parents: Mom and Dad | Sex: Male
    Last location: Marble Rock, IA [42.992, -92.887] D14 hatched in 2012. He was electrocuted by a power pole during his first winter. His death helped spur the Perch Project:
  • Four: Tracked August 2014 to March of 2015
    Birthplace: N2, Decorah IA
    Parents: Mom and Dad | Sex: Female
    Last location: Keota, IA [41.390, -91.979] Four hatched in 2014. She was electrocuted by a power pole during her first winter.
  • D24: Tracked July of 2016 to February of 2021
    Birthplace: N2B, Decorah IA
    Parents: Mom and Dad | Sex: Male
    Last location: Spillville, IA [43.2598, -92.0092] D24 was one of two siblings we tracked in 2016. His transmitter stopped communicating with us, but he may still be alive and could be nesting in NE Iowa. While his transmitter didn’t behave consistently, he summered at least once as far as International Falls, MN based on his location on June 20, 2019.
  • D25: Tracked July of 2016 to July of 2017
    Birthplace: N2B, Decorah IA
    Parents: Mom and Dad | Sex: Male
    Last location: Bluffton, IA [43.4107, -91.8796] D25 was the second of two siblings we tracked in 2016. He was struck and killed by a car while eating roadkill. D25 and D24 on July 17 of 2016
  • D27: Tracked August of 2017 to September of 2022
    Birthplace: N2B, Decorah IA
    Parents: Mom and Dad | Sex: Female
    D27 summers in northwestern Ontario/southeastern Manitoba and winters in NE Iowa. After her first year, most of her winter locations were between 10 and 20 miles away from her natal nest. As far as we know, she is still alive, but her transmitter quit talking to us in September of 2022.
  • D35: Tracked August of 2020 to January of 2021
    Birthplace: N2B, Decorah IA
    Parents: Mom and DM2 | Sex: Female
    Last location: Iowa City, IA [41.5809, -91.5284] D35 was killed by eating a lead slug embedded in game. Learn more about the dangers of lead ammo and D35’s death here:
  • D36: Tracked August of 2020 to April of 2023
    Birthplace: N2B, Decorah IA
    Parents: Mom and DM2 | Sex: Male
    D36 was D35’s sibling. He usually summered in northwest Ontario, roughly 100-200 miles south of D27, and wintered in NE Iowa. After his first year, most of his winter locations were 30-50 miles from his natal nest. He was hit by a car and killed in April of 2023.

At this point, we have no plans to attach transmitters to any more Bald Eagles from the Decorah nest. D1, D24, and D27 are presumably still out there somewhere. Please let us know if you see a Bald Eagle with a transmitter by contacting Amy Ries at [email protected] or call or text 612-237-5793.