Golden eagles are one of the most majestic birds of prey in North America. Known for their large size,keen eyesight, and powerful talons, these apex predators rule the skies. Though golden eagles can be found throughout western North America, their nesting habits remain a mystery to many. In this article, we’ll explore where these raptors build their nests, why they choose specific sites, and what their nests look like.
Cliffsides and Canyons
Golden eagles nest primarily on cliffsides and canyon walls. These steep, elevated sites provide protection from predators and give the eagles a good vantage point. Golden eagles often construct their nests on small ledges jutting out from vertical rock faces. Cliffsides also catch rising thermal air currents that give the large birds the lift they need to take flight. Canyons feature many ideal nesting spots with high, jagged walls encircling open areas used for hunting and soaring.
In addition to natural cliffs and canyons, golden eagles have adapted to nesting on human-made structures as well. Abandoned mining sites, quarries, and gravel pits containing high vertical walls are readily used for nesting. Tall transmission line towers surrounded by open habitat also provide artificial nesting sites for golden eagles in some regions.
Ideal Nesting Locations
When selecting a nesting site, golden eagles look for the following features:
- Elevation – Nests are typically constructed 300-2,000 ft above the ground.
- Protection – Overhanging ledges and walls help shield the nest from weather and predators.
- Inaccessibility – Steep, sheer cliffs limit access to nests by predators and humans.
- Good views – Open surroundings allow for detection of prey and intruders.
- Strong support – Sturdy anchors like large trees or rock crevices are needed to hold massive nests.
Favored Nesting Areas
Some of the specific habitats and regions used most frequently for golden eagle nesting include:
- Canyonlands – Canyons carved by rivers and streams contain prime nesting real estate.
- Cliffsides – Rocky cliffs along mountain ranges and open plains.
- Deserts – Suitable nesting sites exist even in dry, desert landscapes.
- Shorelines – Coastal cliffs above the ocean provide nesting and fishing opportunities.
- Woodland edges – Forest clearings bordering open areas are used.
- Wilderness areas – Remote, protected habitats with minimal human activity.
Nest Construction
Golden eagle nests are among the largest of any bird species. They are built primarily by the female, though the male may deliver some construction material. Breeding pairs often maintain and improve the same nest over successive years.
Nesting Materials
Golden eagles construct their massive nests out of:
- Sticks – Form the bulky base and frame of the nest.
- Greenery – Sprigs, leaves, and shoots provide a soft lining.
- Grass – Adds insulating texture and thickness.
- Feathers – Plucked from prey and the eagles themselves.
- Fur – Gathered from small mammal kills.
- Dirt – Stabilizes the nest structure.
Nest Size
Golden eagle nests are among the largest constructed by any bird. Measurements include:
- Width – 4.5-8 feet
- Depth – 2-4 feet
- Weight – Over 1 ton
These substantial structures provide insulation, protection from weather, and room for eaglets to move about.
Reuse and Repair
Golden eagle pairs frequently use the same nest for multiple seasons. Each year they will return to their nesting site and make repairs and improvements. Adding sticks, grass, and other materials helps maintain the nest’s integrity. Pairs may also construct alternate nests in a single territory, switching between them as needed over the years.
Breeding and Eggs
Golden eagles reach sexual maturity around 4-6 years of age. They mate for life, using the same nest year after year. Egg laying usually takes place from January through mid-April, though timing varies by region.
Clutch Size
The typical golden eagle clutch consists of:
- 1-3 eggs
- 2 eggs – Most common
Only one brood is raised each year. The eggs are laid over a number of days, so eaglets often hatch at different times.
Egg Description
Golden eagle eggs are:
- White
- Blotchy brown spots
- Oval and rounded
- 2.5-3.25 inches long
- 2-2.25 inches wide
- 4-6 ounces in weight
The female does the majority of incubating, only leaving the nest to eat. The male will help incubate occasionally. Incubation lasts about 35-45 days before hatching.
Nestlings
Golden eagle chicks grow rapidly in the nest. Key facts about nestlings include:
- Covered in white down at hatching
- Weigh 4-5 ounces at hatching
- Can make high-pitched cheeping sounds
- Fed by parents for the first 8 weeks
- Fledge at 10-12 weeks old
The eaglets jockey for food and survival, with the older chick sometimes killing its younger sibling. Only the strongest nestling typically survives.
Habitat Loss and Protection
Golden eagle populations declined over much of their North American range between the 1950s-1970s. Habitat loss was a major factor, as breeding areas were altered by urbanization, agriculture, and timber harvesting. The widespread use of pesticides like DDT also reduced golden eagle numbers by causing eggshell thinning.
Current Populations
Improved legal protections and reduced pesticide use have helped golden eagle populations rebound. Current estimates place golden eagles at:
- Alaska: 30,000-50,000 pairs
- Canada: 5,000-10,000 pairs
- Western U.S.: At least 20,000 pairs
More precise data is needed for many regions to fully gauge current populations though.
Ongoing Threats
Some threats to golden eagles remain today. These include:
- Habitat degradation – From human development, recreation, grazing, etc.
- Lead poisoning – From scavenging carcasses with lead bullet fragments.
- Collisions – With vehicles and wind turbines.
- Illegal killing – Rare but still occurs for feathers, trophies, etc.
Conservation Measures
Steps taken to help conserve golden eagle populations include:
- Legal protection – Golden eagles are protected under the Bald Eagle Protection Act and Migratory Bird Treaty Act.
- Nest buffers – Human activity may be restricted near nesting sites.
- Habitat preservation – Conservation of wilderness areas and bird sanctuaries.
- Lead reduction – Switching to non-lead ammunition aids scavenging eagles.
- Power pole modifications – Perch deterrents and insulation help prevent electrocution.
Continued habitat protections and close monitoring of threats will be key to ensuring thriving golden eagle populations across North America.
Conclusion
Golden eagles are icons of the wilderness, thanks to their large size, power, and grace. They nest primarily on remote cliffsides and canyon walls that provide elevation, protection, and open views. Massive nests of sticks, grass, and other materials are built and maintained each year by breeding pairs. Though habitat loss impacted golden eagle numbers in the past, focused conservation efforts have assisted the recovery of populations across much of their range. Protecting these magnificent raptors into the future will require continued stewardship of the wild land and resources they depend on.