Golden eagles are one of the largest, fastest and most powerful birds of prey in North America. They have sharp, powerful talons and beaks that make them effective hunters able to take down prey much larger than themselves. Though they mainly feed on smaller animals like rabbits, ground squirrels and prairie dogs, golden eagles are certainly capable of killing animals as large as deer fawns and pronghorn antelope. However, their ability to take down large prey depends on many factors.
Size and Strength of Golden Eagles
Golden eagles are quite large and strong birds, though considerably smaller than the prey animals they occasionally attack.
- Wingspan: 6-7.5 feet
- Body Length: 27-37 inches
- Weight: 7-15 pounds
Comparatively, a white-tailed deer fawn may weigh between 14-30 pounds at birth, while a pronghorn fawn generally weighs 7-10 pounds when born. So while much larger than the eagle, fawns make vulnerable prey, especially the smaller pronghorn young.
The golden eagle’s foot contains one long talon or “digit” that can deliver a stabbing blow with deadly force. Researchers have estimated the grip strength of large eagles like the golden to be around 400 pounds per square inch. This is strong enough to swiftly crush the skull, spine or other bones of prey. The eagle’s beak is also thick and powerful, able to tear flesh and deliver disabling strikes.
So while a golden eagle is dwarfed in size by larger prey like deer, its sheer speed, strength and deadly talons allow it to take down animals many times its own weight.
Hunting Techniques and Prey Size
Golden eagles use a variety of hunting techniques, ranging from stealthily approaching prey on the ground to spectacular stoops from great heights. Their tactics vary based on the type and size of prey.
Small Mammals, Birds and Reptiles
When targeting smaller animals like rabbits, ground squirrels, prairie dogs and small birds, golden eagles often cruise low over the landscape, using ridges or vegetation for cover. Once within around 100 yards, they accelerate into a swift, low flight to quickly grab or slam into their prey before it can react and escape down a burrow. Smaller prey like these are the golden eagle’s main food source.
Larger Prey – Deer and Pronghorn Fawns
Golden eagles are less likely to attack larger prey, which can pose higher risk of injury. But they may opportunistically target vulnerable fawns in their first weeks of life. Slower, weaker fawns make for easier targets than full-grown deer and pronghorns.
To attack larger prey, golden eagles often utilize the element of surprise, approaching fawns stealthily from downwind or behind cover. They may land on an elevated perch and swoop down on prey before the fawn is aware. The initial impact can stun the fawn, allowing the eagle to quickly deliver a killing bite.
Alternately, golden eagles may perform high soaring flights to scan below for vulnerable fawns. Once spotted, they enter into a swift, steep stoop or dive, reaching speeds over 150 mph. They aim to strike the skull or spine with talons or beak. Fawns may be killed or severely injured on initial impact. If not, the eagle latches on with its talons to deliver further blows.
Larger Ungulates – Adult Deer, Pronghorn, Bighorn Sheep
Healthy adult ungulates like deer, pronghorn and bighorn sheep are generally too large and strong for a golden eagle to successfully attack. However, there are rare reports of golden eagles preying on ungulates weakened by harsh winter conditions or sickness.
In these cases, the eagles likely target animals that appear vulnerable – struggling to stand, walking slowly, isolated from the herd. If the eagle can deliver a precise, crippling blow, it may be able to finish off a weakened animal. This is an opportunistic hunting strategy rather than the norm. Healthy, full grown deer and other ungulates pose substantial injury risk and are rarely attacked.
Factors Impacting Hunting Success
Whether a golden eagle can successfully kill large prey depends on a variety of changing factors.
Vulnerability of Prey
As mentioned, golden eagles are far more likely to attack younger, weaker prey that poses less threat of injury to the raptor. Deer and pronghorn fawns under two weeks old make prime targets, as they lack speed, stamina and defensive abilities. Slower reflexes make them more vulnerable to surprise attack. In contrast, healthy adult deer can run at speeds over 30 mph, kick powerfully with hooves, and are vigilant in watching for threats. Only underaged, sick or crippled individuals are potentially vulnerable.
Environmental Conditions
Golden eagles are most successful hunting in open habitats with good visibility, such as prairies, plains and desert scrublands. Low vegetation allows them to spot and pursue prey more easily. Hills, ridges and cliffs provide elevated perches for scanning the landscape.
In forested areas, dense cover makes it harder for eagles to spot and ambush prey. Their wingspan can also be obstructed by tree branches and undergrowth. However, open clearings in woodlands can provide suitable hunting grounds.
Deep snow and cold temperatures in winter may also benefit golden eagles. Young fawns and other prey are hindered in their movements, allowing the eagles to overtake them more easily. Struggling prey also makes for easier targets.
Eagle Experience and Physical Condition
Adult golden eagles with years of experience are generally the most capable hunters. Their flying and targeting abilities are well-honed. They know how to maximize the element of surprise and strike vulnerable points to swiftly kill or incapacitate prey.
Juvenile eagles on their own for the first time lack this experience and finesse. They may be more likely to botch attacks on large prey.
The eagle’s physical condition is also a factor. Lean, fit and healthy eagles will have the speed and strength to bring down more challenging prey. Any wing or leg injuries could impact an eagle’s success. Molting and the replacement of flight feathers may also temporarily hinder aerial maneuverability required for stoops.
So in optimal conditions, a mature golden eagle in peak physical shape has the best odds of taking a large animal like a deer fawn. But various factors play a role in determining success.
Biggest Confirmed Golden Eagle Prey
So what is the largest animal a golden eagle has verifiably killed? Here are some documented cases:
- Pronghorn fawn, Wyoming – 10 lbs
- Siberian roe deer fawn, Russia – 16 lbs
- Reindeer calf, Russia – 22 lbs
- Red fox, Scotland – 10-15 lbs
Heavier ungulate prey have also been reported, including:
- Mule deer fawn, Wyoming – 25 lbs
- Siberian ibex kid, Russia – approx 30 lbs
The largest prey convincingly documented have been on the smaller side for deer and antelope young, likely under 3 weeks old and still building strength and speed.
Claims of golden eagles preying on larger animals like adult coyotes, wolves, bobcats and such are unverified. These species pose a high risk of injury and are unlikely attacked except maybe if severely disabled.
Typical Prey Weight Range
While golden eagles can and occasionally do kill larger prey, the vast majority of their diet consists of smaller animals. Some estimated typical prey weight ranges:
Small Mammals
- Rabbits – 2-5 lbs
- Ground squirrels – 0.5-2 lbs
- Prairie dogs – 2-3 lbs
Birds
- Ducks and geese – 3-6 lbs
- Pheasants – 2-4 lbs
- Grouse – 1-2 lbs
Reptiles
- Snakes – up to 6 lbs
- Lizards – up to 1 lb
When readily available, smaller prey make for an easier, lower-risk hunting strategy to sustain golden eagles. But taking the occasional fawn or lamb can provide a high-calorie bonus.
Conclusion
Golden eagles are capable of taking down impressive prey, including deer and pronghorn fawns exceeding their own body weight. But a number of factors have to align for them to succeed, including vulnerable prey, ideal habitat and hunting conditions, and a healthy, experienced eagle. While news-making cases exist of golden eagles killing coyote or even mountain goat-sized animals, these are likely rare events involving compromised prey. In most cases, golden eagles stick to smaller prey that can be caught more easily and with lower risk of injury. But the large raptors will opportunistically target larger quarry when the conditions allow. Their size, speed and ultra-powerful talons make golden eagles one of the most formidable aerial predators capable of killing prey far larger than themselves.
