Epic Battles: The Largest Eagle Ever vs. Black Bear

Written by Kyle Glatz
Published: December 14, 2022
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When we think of the deadliest modern animals, we’re far more likely to worry about bears than birds. Yet, the largest eagle ever to exist, if it were still alive today, would probably make people look to the sky before walking to their cars. That brings us to a far more interesting question. What would happen in a fight between the largest eagle ever vs a bear?

After all, we know that bears are some of the toughest creatures to roam the planet right now. For the sake of making this fight interesting, we’re going to use information about an American black bear to compare against the largest eagle ever, an animal called Haast’s eagle.

Comparing the Largest Eagle and a Black Bear

Haast's eagle attacking New Zealand moa

Haast’s eagle is the largest eagle to ever have lived in the world.

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©John Megahan, CC BY 2.5, via Wikimedia Commons – License

Largest Eagle EverBlack Bear
SizeWeight: 20 to 26 pounds, up to 36 pounds
Height: could grow up to almost 3 feet
Wingspan: 6.5 to about 9 feet
Weight: between 220 and 660 pounds
Length: 4.25 to 6 feet long
Height: 2.5 to 3 feet tall at the shoulder
Speed– Could perhaps dive at speeds of 50 mph, estimated from the harpy eagle– Top speed of 30 mph
– Capable tree climber
Defenses– Ability to fly keeps the largest eagle safe
– Large body allows the eagle to safely fight its prey    
– Great senses help the bear identify prey and predators from far off
– Thick fur and fat layers offer protection to the bears
– Their speed can help them escape from adverse situations
Offensive Capabilities– Talons that measure up to 3 inches
– Beak that measures up to 5.1 inches long
– Incredibly high grip strength that could have easily exceeded 1,000 PSI
– Teeth that measure up to 2.5 inches long
– Bite force around 800 PSI
– Claws that measure about 1 inch and are somewhat sharp
– Powerful swipe and smack attacks
Predatory Behavior– Ambush predator that attacked from the sky
– Killed by exsanguinating prey or by outright crushing its skull
– Attacked from above its prey, digging in massive talons and then using its beak to go after vital organs
– Omnivorous creatures that attack the head and neck of prey when they strike
– Mostly chase down their prey and kill it

What Are the Key Differences Between the Largest Eagle Ever and a Bear?

black bear

The average weighs between 220 and 660 pounds.

©Wild Art/Shutterstock.com

The key differences between the largest eagle ever and a bear are found in their morphology and size. Haast’s eagle was a large bird that stood about 3 feet tall, weighed perhaps 36 pounds at its utmost, and had a wingspan of upwards of 9 feet. Aside from the wingspan, the other measures of Haast’s eagle were very impressive.

Meanwhile, the average black bear is a large, fur-covered mammal that weighs between 220 and 660 pounds. These animals can grow up to 6 feet long and measure about 2.5 to 3 feet tall at the shoulder when they’re walking on all fours.

These key differences may seem to favor one animal over the other in this battle. Yet, when we look closer, we can find some areas in which the eagle can appear as a more powerful adversary.  

What Are the Key Factors in a Fight Between the Largest Eagle Ever and a Black Bear?

The most significant factors in fights between animals are typically their size and ability to inflict damage on others. This fight is not going to be much different in that respect. However, we also have to consider the fact that Haast’s eagle hunted moas, flightless birds that were about the same weight as the average black bear.

This necessitates a closer look at five elements that will help us understand the advantages that each animal possesses against the other. Let’s look at factors, determine which animal is stronger in every case, and use that information to come up with a good understanding of how this fight would end.

Haast’s Eagle vs. Black Bear: Size

animals unique to North America: American black bear

The bear has the size advantage over the largest eagle.


The average bear is far larger than the largest eagle that ever lived. The typical black bear weighs between 220 and 660 pounds at its largest, stands between 2.5 and 3 feet tall when walking on all fours, and grows about 4.25 to 6 feet long. They are large mammals.

Meanwhile, the largest eagle ever weighed between 20 and 26 pounds on average, but they could reach a top weight of about 36 pounds. Furthermore, they grew up to 3 feet tall and had a wingspan between 6.5 and 9 feet long. They were absolutely massive for flying birds.

The bear has the size advantage in this fight.

Haast’s Eagle vs. Black Bear: Speed

The average bear is not as slow as its large body suggests. Bears can run at speeds of about 30 mph. Unfortunately, we don’t have many great estimates for the flying capabilities of the largest eagle. At least, we don’t know for sure how fast this bulky bird could fly.

The modern-day harpy eagle can dive at 50 mph. So, it’s not unreasonable to think that Haast’s eagle could reach that speed. Yet, that speed is certainly not something the bird could keep up the entire fight, especially after it landed.  

All things considered, the bird starts the fight with the speed advantage, but that rapidly shifts to the bear after the initial contact.

Haast’s Eagle vs. Black Bear: Defenses

Giant Haasts eagle

©John Megahan / CC BY 2.5 – License

The largest eagle ever had to rely on its speed and flying ability to stay safe. They were ambush predators that would take one well-aimed attack and bring down their prey, flightless birds called moa.

Meanwhile, bears use their bulkiness, speed, and senses to keep themselves safe from attackers. Bears are large creatures with thick fur and skin that absorb attacks. They also have a layer of fat that can help reduce the impact of slicing and stabbing attacks. Lastly, they have large bodies and high strength, making it hard for another animal to bring them to the ground and kill them without taking serious damage on their own.

The bear has the best defenses overall, but the eagle’s ability to simply fly away from an adverse situation helps it a great deal.

Haast’s Eagle vs. Black Bear: Offensive Capabilities


This extinct bird was a powerhouse, built for fast, powerful attacks.

©DO’Neil / CC BY-SA 3.0 – License

The largest eagle ever was built for high-powered, fast attacks that would kill their prey quickly and easily. They had beaks that measured up to 5.1 inches long, talons that measured almost 3 inches in length on average, and a grip strength that could exceed 1,000 PSI.

That’s enough to simply crush the skulls of their prey. They could also attack by grabbing their prey and using their beak to tear them open at vital areas.

Meanwhile, bears rely on their powerful bite force of 800 PSI to drive 2.5-inch canine teeth into their prey to break spines and vertebrae. Bears are multi-faceted, though. They like to maul their prey with their sharp claws and powerful swats of their paws too.

All in all, both animals are equipped for an offensive battle, but the bear is more suited to a long fight.

Haast’s Eagle vs. Black Bear: Predatory Behavior

Bears are not as predatory as the largest eagle ever. They are opportunists more than predators. Still, they have the power and senses to find and kill prey. Bears often locate and then chase down their prey before killing it with a vicious mauling attack.

Meanwhile, the largest eagle was an ambush predator that would attack from the sky. It’s believed that they would use a few different ways to kill their prey including crushing their skull or exsanguinating them with deadly beak and talon attacks. They could then keep watch over their fallen prey, feeding for several days.  

Who Would Win in a Fight Between the Largest Eagle and a Black Bear?

Black Bear Population by State

A black bear would likely win in a battle between it and Haast’s eagle.


A bear would win a fight against the largest eagle. Certainly, Haast’s eagle was a deadly bird, and it could take down prey that was roughly the same weight as a black bear. Yet, the largest eagle never fought anything close to as strong and vicious as an angered bear that would fight back during the initial assault.

The bear’s robust body and powerful bones give it a good shot at surviving the initial attack from the eagle. If it can survive that first blow, then the odds shift in favor of the large, strong mammal.

The fight would start with a diving attack from the eagle. If it managed to attack the bear’s spine, neck, or head, then the eagle could potentially score a victory in some cases. The more likely event would see the largest eagle digging into the bear and getting nothing but fur, flesh, and fat in its talons and beak.  

The bear would struggle at first, but it would use its claws to tear into the lighter animal. The eagle is going to let up at some point due to the immense damage being dealt to it. Once the bear lands a few good strikes, the bird is going to flee or get mauled to death.

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About the Author

Kyle Glatz is a writer at A-Z-Animals where his primary focus is on geography and mammals. Kyle has been writing for researching and writing about animals and numerous other topics for 10 years, and he holds a Bachelor's Degree in English and Education from Rowan University. A resident of New Jersey, Kyle enjoys reading, writing, and playing video games.

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  1. International Association for Bear Research and Management, Available here: https://www.bearbiology.org/bear-species/american-black-bear/
  2. National Wildlife Federation, Available here: https://www.nwf.org/Educational-Resources/Wildlife-Guide/Mammals/black-bear
  3. New Zealand Birds Online, Available here: https://nzbirdsonline.org.nz/species/haasts-eagle#:~:text=A%20robust%2C%20large%2Dbodied%20eagle,up%20to%2090%20cm%20tall.