Quick Answer
The tallest golden eagle on record measured 106 cm (3 ft 6 in) in total length. However, most golden eagles are much smaller, with an average wingspan of 180–220 cm (5 ft 11 in–7 ft 3 in). Females are larger than males, weighing 3.6 to 6.7 kg (7.9 to 14.8 lb) compared to 2.3 to 4.2 kg (5.1 to 9.3 lb) for males.
The golden eagle (Aquila chrysaetos) is one of the largest, fastest, nimblest raptors in North America. With broad, rounded wings and a short, compact tail, these powerful birds of prey are built for speed and aggression. Their light brown plumage allows them to soar high above their mountain habitats, using powerful eyesight to spot prey across vast distances. When hunting, golden eagles employ a repertoire of aerial maneuvers at speeds over 320 km/h (200 mph) to strike unsuspecting quarry.
Golden eagles are most well known for their massive size. As one of the world’s largest eagles, their height and wingspan can be imposing. But just how big do golden eagles get? What is the wingspan of the largest golden eagle on record? And how much does the heaviest golden eagle weigh? This article will explore the maximum dimensions of these colossal raptors.
Typical Size Range of Golden Eagles
Most golden eagles measure much smaller than the maximum confirmed sizes. Across their range, golden eagles display a high degree of size variability between sexes and subspecies. However, some general trends are apparent:
Wingspan
– Male: 1.8-2.0 m (5 ft 11 in–6 ft 7 in)
– Female: 2.0-2.3 m (6 ft 7 in–7 ft 7 in)
Length (bill to tail)
– Male: 70–90 cm (28–35 in)
– Female: 85–110 cm (33–43 in)
Weight
– Male: 2.3-4.2 kg (5.1-9.3 lb)
– Female: 3.6-6.7 kg (7.9-14.8 lb)
So while some golden eagles do reach enormous sizes, most are about 25% smaller than the maximum confirmed measurements. Females are noticeably larger than males in all dimensions. Still, even an average-sized female golden eagle is a massive, powerful raptor.
Largest Recorded Measurements
A number of outsized golden eagles have been documented over the years. These are the largest credible measurements confirmed for the species:
Wingspan
The largest wingspan reported for a golden eagle is 2.49 m (8 ft 2 in). This eagle was an abnormally large female captured and measured in Montana in the 1970s.
Length
The longest golden eagle was a male from the Netherlands measured in 1979. It reached 1.06 m (3 ft 6 in) from bill to tail tip.
Weight
An unusually heavy female golden eagle was captured in Kamloops, British Columbia in 1977. This bird weighed a remarkable 9 kg (19.8 lb), almost 50% heavier than a typical female.
So while golden eagles usually weigh 4-7 kg (9-15 lb), the scales can tip significantly higher for outliers. But note that measurements for both the longest and heaviest eagles could not be independently verified, so they must be regarded as approximate.
World’s Tallest Golden Eagle
Based on the recorded measurements, the tallest golden eagle was likely the giant female from Montana with a 2.49 m (8 ft 2 in) wingspan. Since golden eagle bodies are compact and streamlined, their height when perched is generally proportional to their wingspan. Therefore, the tallest golden eagles should correlate with those having the longest wingspans.
For a golden eagle with a 2.49 m (8 ft 2 in) wingspan, a reasonable estimate for its total standing height would be around 75-80 cm (2.5-2.6 ft) from head to talons. No golden eagle height has apparently been directly measured, but the above extrapolation fits with typical wingspan-to-height ratios.
So while golden eagles can appear almost as tall as a human when perched, the tallest individuals likely reach no more than 0.8 m (2.6 ft) high at most. Their great height comes from their tremendous wingspans, not their body size. Still, that is impressively tall for a raptor!
Role of Geographic Variation
Why do some golden eagles grow so much larger than others? Part of the reason involves geographic variations between populations. The largest golden eagles tend to occur in western North America, especially in Alaska and western Canada. The subspecies A. c. canadensis includes the bulkiest golden eagles in the world.
Meanwhile, smaller subspecies are found in Eurasia and the desert southwest. The small body size likely evolved to aid survival in hot climates. Larger golden eagles tend to occur in cooler areas where bigger bulk helps conserve heat.
So the tallest golden eagles all hail from subarctic regions of North America. The combination of huge size and cold climate results in some truly massive specimens.
Diet and Abundant Prey
Access to plentiful prey resources also plays a role in attaining huge size. Abundant food during development allows young golden eagles to fledge at maximum weight. Quality nutrition then continues to spur rapid growth before adulthood.
The largest golden eagles occupy territories with diverse prey. From rabbits and marmots to geese and young deer, ample food supports vigorous growth. Even as adults, good hunting lets big eagles maintain peak condition over many years.
So favorable habitat and prey availability help some golden eagles reach record-breaking dimensions. Where food is scarce, golden eagles remain constrained to smaller sizes.
Significance of Large Size
Why does maximum body size matter for golden eagles and other raptors? Larger size confers several advantages:
- Larger wings enable golden eagles to soar more efficiently for long periods using less energy.
- Increased muscle mass allows them to exert higher flight speeds and lift heavier prey.
- Bigger talons and beaks provide greater killing power and ability to subdue large prey.
- Sheer bulk helps establish dominance over competitors for nest sites and hunting territories.
So attaining great size makes golden eagles more effective predators. It maximizes their athletic prowess and lets them utilize a wider range of prey. Bulk also enhances status, as very large raptors command respect from conspecifics when defending territories.
For a female golden eagle, surpassing 2 m (6.6 ft) across in wingspan denotes an extremely formidable bird. At the upper limits, only the largest females can physically dominate their mate and fend off rival eagles. Thus, gigantic size carries practical advantages for survival and reproduction.
Comparison to Other Eagles
How does the golden eagle’s maximum size compare to other large eagles worldwide? The golden sits near the top:
Species | Max Wingspan |
---|---|
Golden eagle | 2.49 m (8 ft 2 in) |
Martial eagle | 2.6 m (8 ft 6 in) |
Steller’s sea-eagle | 2.5 m (8 ft 2 in) |
Harpy eagle | 2.0 m (6 ft 7 in) |
Philippine eagle | 2.0 m (6 ft 7 in) |
Wedge-tailed eagle | 2.3 m (7 ft 7 in) |
Bald eagle | 2.4 m (7 ft 10 in) |
Only Africa’s martial eagle strictly surpasses the golden, though some Steller’s sea-eagles nearly match it. Overall, the golden ranks among the most physically imposing eagles worldwide. No other northern hemisphere raptors come close in wingspan or mass.
So despite regional variations in size, the golden eagle remains one of the world’s longest, heaviest raptors. Its great stature helps explain why it has such an expansive range and ability to utilize diverse prey.
Role of Sexual Dimorphism
One more key fact about golden eagle size is the degree of sexual dimorphism. As with most raptors, female golden eagles average about 25-50% larger than males in all dimensions. This great divergence stems from differences in ecological roles.
Male and female golden eagles employ cooperative breeding, with both partners defending a territory and raising young together. But sex-based divisions of labor also occur:
- Females almost solely perform incubation and brooding duties.
- Males do more frequent hunting and food provisioning.
- Females are more aggressive toward intruders.
The larger female size maximizes reproductive success. A heavier female can lay more eggs and brood nestlings more easily. Greater bulk also lets her better fend off rivals at the nest site.
For the male, moderate size aids flying long distances to hunt prey. Remaining light and agile enhances foraging prowess to feed the family.
So optimal size results from differing fitness needs of males and females. The outcome is males around 75-90% the bulk of females on average. This divergence explains why the longest, tallest, and heaviest golden eagles are typically females.
Conclusion
The tallest golden eagle ever documented measured around 2.5 m (8 ft 2 in) across the wings. Based on typical proportions, its standing height was likely 0.75-0.8 m (2.5-2.6 ft) from head to feet. No other northern hemisphere raptor exceeds the golden in average wingspan or weight.
Achieving tremendous size provides golden eagles with advantages in speed, strength, hunting ability, and competition with rivals. But regional variations mean not all golden eagles attain such monumental stature. The largest eagles inhabit northern latitudes where ample prey allows rapid growth. Smaller desert and Eurasian subspecies also exist.
In all cases, female golden eagles grow much bulkier than males. This sexual dimorphism relates to differing reproductive duties and enhances breeding success. So the tallest golden eagles are giants among giants – extreme examples of a species optimized by evolution for power and agility.