9 Extinct Big Birds

Our friend from Sesame Street may be a big bird, but he’s tiny compared to some real birds that have roamed the earth in the past. Here are a representative few of these big birds we will never see alive again. In some cases, that’s a comforting thought.

1. Gastornis

There were four or five species of the bird genus Gastornis that lived in North America, Europe, and Asia 55 to 40 million years ago. The North American bird was previously known as Diatryma before it was reclassified. Gastornis were big flightless birds, the largest species being Gastornis giganteus, which grew to 6.5 feet tall. But they weren’t anything to be afraid of -unless you were a plant. Its powerful beak was used to crush seeds and fruit. That’s right, this bird was a vegetarian! However, it could well have used that beak as a defense against attackers. The top picture is a 1917 illustration of what Gastornis may have looked like.

2. Pelagornis Chilensis

Photograph by Ghedoghedo.

Just a few years ago, it was thought that Pelagornis chilensis had the largest wingspan possible for a bird at 17 feet. P. chilensis lived in Chile 5 to 10 million years ago, where it skimmed the ocean surface for fish. That large wingspan was necessary to carry a 64-pound flying body. It is classified as a pelagornithid, or bony-toothed (“pseudotooth”) bird. Some other species of pelagornithids may have survived long enough to have been seen by humans.

3. Pelagornis Sandersi

Photograph by Ryan Somma.

The idea that 17 feet was the upper wingspan limit for flying birds was shattered in 2014. Pelagornis sandersi is largest flying bird yet found, with a wingspan of up to 24 feet! The fossil was found in Charleston, South Carolina in 1983, but it was kept in storage for thirty years before anyone studied its measurements. And now that we know how big this pseudotooth was, the mystery that remains is how it ever achieved liftoff with such long wings. It’s possible that the bird jumped off seaside cliffs.

4. Andalgalornis

Illustration by John Conway.

Andalgalornis steulleti was a Phorusrhacid that stood 4.5 feet tall and weighed about 90 pounds. Phorusrhacids, the 18 species of the family Phorusrhacidae, are commonly called “terror birds,” because they were huge apex predators during the Cenozoic era. Andalgalornis lived in Argentina around 6 million years ago. Its skull was distinctively thin as seen from above, but its narrow beak appears huge from the side. Andalgalornis had a rigid-boned skull that gave it a powerful bite compared to other birds with more lightweight construction.

5. Kelenken

Illustration by FunkMonk (Michael B. H.).

The largest terror bird was Kelenken guillermoi, which lived 15 million years ago in Argentina. Kelenken stood somewhere between seven and ten feet tall. Its lower leg bone is 45 centimeters (18 inches), and it had a skull 71 centimeters (28 inches) long with a 45 centimeter beak. This flightless bird weighed around 500 pounds and killed its prey with its massive beak.

6. Titanis Walleri

Illustration by Dmitry Bogdanov.

The terror bird Titanis walleri became an American Phorusrhacid as a result of species moving over the Isthmus of Panama about three million years ago. Its fossils have been found in Texas and Florida. T. walleri lived from 5 to 2 million years ago. This bird stood eight feet tall and weighed over 300 pounds. The species, in a fictionalized form, stars in the 2006 novel The Flock by James Robert Smith.

7. Haast’s Eagle

Illustration by John Megahan.

Haast’s eagle is extinct, but not exactly prehistoric. Scientists believe the youngest fossils may be only 500 years old, which means the eagle’s extinction was probably due to human hunting of the eagle’s main prey, the moa. Haast’s eagle (Harpagornis moorei) was native to New Zealand, and was the largest eagle that ever lived. The female, larger than the male, weighed 10–15 kilograms (22–33 pounds) and had a wingspan of 8-10 feet. The species had a relatively short wingspan for its weight.

8. Dinornis

Speaking of New Zealand, it was once home to an extinct bird genus that actually resembled Sesame Street’s Big Bird. Dinornis, or the giant moa, was the main food source of Haast’s eagle until it was hunted to extinction by the Māori in the 15th century. The female of the species Dinornis robustus stood 12 feet tall and weighed over 500 pounds, possibly up to 600 pounds! New Zealand had no mammals before human settlers arrived from Polynesia, and so they thrived for 40,000 years, despite Haast’s eagle.

9. Argentavis

Illustration by Stanton F. Fink.

With an estimated wingspan of 23 feet, Argentavis magnificens is the only extinct bird found so far that can approach Pelagornis sandersi in wingspan. And we have more fossil specimens of the “magnificent bird of Argentina.” It existed more recently than many of the birds on this list, living around six million years ago. A. magnificens weighed between 60 and 80 kg (140-180 pounds), so it is a mystery how it managed to take off, but it is inferred that the bird soared on thermal currents instead of flapping its wings. Argentavis ate carrion instead of swooping down on live prey. A. magnificens is related to modern vultures.

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14 Bold Facts About Bald Eagles
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iStock

Bald eagles are powerful symbols of America—but there’s a whole lot more to these quirky birds.

1. YOUNG BALD EAGLES AREN'T BALD.

A young bald eagle with a brown head on a beach.
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So obviously adult bald eagles aren't really bald, either—their heads have bright white plumage that contrasts with their dark body feathers, giving them a "bald" look. But young bald eagles have mostly brown heads. In fact, for the first four or five years of their lives, they move through a complicated series of different plumage patterns; in their second year, for instance, they have white bellies.

2. BALD EAGLES SOUND SO SILLY THAT HOLLYWOOD DUBS OVER THEIR VOICES.

A red-tailed hawk.
A red-tailed hawk's screech is usually dubbed over the bald eagle's weaker scream.
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It's a scene you’ve probably seen countless times in movies and on TV: An eagle flies overhead and emits a rough, piercing scream. It's a classic symbol of wilderness and adventure. The only problem? Bald eagles don't make that sound.

Instead, they emit a sort of high-pitched giggle or a weak scream. These noises are so unimpressive that Hollywood sound editors often dub over bald eagle calls with far more impressive sounds: the piercing, earthy screams of a smaller bird, the red-tailed hawk. If you were a fan of The Colbert Report, you might remember the show's iconic CGI eagle from the opener—it, too, is making that red-tailed hawk cry. Listen for yourself and decide who sounds more impressive.

3. THEY EAT TRASH AND STOLEN FOOD.

Two bald eagles guard their prey against two magpies on a snowy field.
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Picture a majestic bald eagle swooping low over a lake and catching a fish in its powerful claws. Yes, bald eagles eat a lot of fish—but they don't always catch them themselves. They've perfected the art of stealing fish from other birds such as ospreys, chasing them down until they drop their prey.

Bald eagles will also snack on gulls, ducks, rabbits, crabs, amphibians, and more. They'll scavenge in dumpsters, feed on waste from fish processing plants, and even gorge on carrion (dead, decaying animals).

4. BALD EAGLES USUALLY MATE FOR LIFE ...

Two bald eagles perched on a tree.
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Trash and carrion aside, they're pretty romantic animals. Bald eagles tend to pair up for life, and they share parenting duties: The male and the female take turns incubating the eggs, and they both feed their young.

5. … AND THEY LIVE PRETTY LONG LIVES.

Two bald eagles sitting on a rock.
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Those romantic partnerships are even more impressive because bald eagles can survive for decades. In 2015, a wild eagle in Henrietta, New York, died at the record age of 38. Considering that these birds pair up at 4 or 5 years of age, that's a lot of Valentine's Days.

6. THEY HOLD THE RECORD FOR THE LARGEST BIRD'S NEST.

Two bald eagles in their large nest.
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Bald eagles build enormous nests high in the treetops. The male and female work on the nest together, and this quality time helps them cement their lifelong bond. Their cozy nurseries consist of a framework of sticks lined with softer stuff such as grass and feathers. If the nest serves them well during the breeding season, they'll keep using it year after year. And, like all homeowners, they can't resist the thought of renovating and adding to their abode. Every year, they'll spruce it up with a whopping foot or two of new material.

On average, bald eagle nests are 2-4 feet deep and 4-5 feet wide. But one pair of eagles near St. Petersburg, Florida, earned the Guinness World Record for largest bird’s nest: 20 feet deep and 9.5 feet wide. The nest weighed over two tons.

7. FEMALES ARE LARGER THAN MALES.

Two bald eagles in their large nest.
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In many animal species, males are (on average) larger than females. Male gorillas, for example, dwarf their female counterparts. But for most birds of prey, it's the opposite. Male bald eagles weigh about 25 percent less than females.

Scientists aren't sure why there's such a size difference. One reason might be the way they divide up their nesting duties. Females take the lead in arranging the nesting material, so being bigger might help them take charge. Also, they spend longer incubating the eggs than males, so their size could intimidate would-be egg thieves.

If you're trying to tell male and female eagles apart, this size difference may help you—especially since both sexes have the same plumage patterns.

8. TO IDENTIFY THEM, LOOK AT THE WINGS.

A bald eagle flies across the water.
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People often get excited about a big soaring bird and yell "It's an eagle!” just before it swoops closer and … oops, it's a vulture. Here's a handy identification tip. Bald eagles usually soar with their wings almost flat. On the other hand, the turkey vulture—another dark, soaring bird—holds its wings up in a shallow V shape called a dihedral. A lot of large hawks also soar with slightly raised wings.

9. THEY'RE COMEBACK KIDS.

Baby eagle chicks in a nest.
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Before European settlers arrived, bald eagles were abundant across the U.S. But with settlement came habitat destruction, and the settlers viewed the eagles as competition for game and as a threat to livestock. So many eagles were killed that in 1940 Congress passed an act to protect the birds.

Unfortunately, another threat rose up at about that time. Starting after World War II, farmers and public health officials used an insecticide called DDT. The chemical worked well to eradicate mosquitos and agricultural pests—but as it traveled up the food chain, it began to heavily affect birds of prey. DDT made eagle eggshells too thin and caused the eggs to break. A 1963 survey found just 471 bald eagle pairs in the lower 48 states.

DDT was banned in the early 1970s, and conservationists began to breed bald eagles in captivity and reintroduce them in places across America. Luckily, this species made a spectacular recovery. Now the lower 48 states boast over 9700 nesting pairs.

10. THEY'RE UNIQUELY NORTH AMERICAN.

An African fish eagle flies over the water.
The African fish eagle is a relative of the North American bald eagle.
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You've probably heard of America's other eagle: the golden eagle. This bird lives throughout much of the northern hemisphere. But the bald eagle is only found in North America. It lives across much of Canada and the U.S., as well as northern parts of Mexico.

Though it may be North American, the bald eagle has seven close relatives that are found throughout the world. They all belong to the genus Haliaeetus, which comes—pretty unimaginatively—from the Latin words for "sea" and "eagle." One relative, the African fish eagle, is a powerful symbol in its own right. It represents several countries; for example, it's the national symbol of Zambia, and graces the South Sudanese, Malawian, and Namibian coats of arms.

11. THEY'RE AERIAL DAREDEVILS.

A bald eagle carries a fish off in its talons.
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It seems too weird to be true: While flying, bald eagles sometimes grab each other's feet and spin while plummeting to the earth. Scientists aren't sure why they do this—perhaps it's a courtship ritual or a territorial battle. Usually, the pair will separate before hitting the ground (as seen in this remarkable set of photographs). But sometimes they hold tight and don't let go. These two male bald eagles locked talons and hit the ground with their feet still connected. One subsequently escaped and the other was treated for talon wounds.

12. THEIR EYES ARE AMAZING.

Close-up of a bald eagle's face.
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What if you could close your eyes and still see? Besides the usual pair of eyelids, bald eagles have a see-through eyelid called a nictitating membrane. They can close this membrane to protect their eyes while their main eyelids remain open. The membrane also helps moisten and clean their eyes.

Eagles also have sharper vision than people, and their field of vision is wider. Plus, they can see ultraviolet light. Both of those things mean the expression "eagle eye" is spot-on.

13. THEY MIGRATE … SORT OF.

A bald eagle sits in a snowy tree.
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If you're a bald eagle that nests in northern Canada, you'll probably head south for the winter to avoid the punishing cold. Many eagles fly south for the winter and return north for the summer—as do plenty of other bird species (and retired Canadians). But not all bald eagles migrate. Some of them, including individuals in New England and Canada's Maritime provinces, stick around all year. Whether or not a bird migrates depends on how old it is and how much food is available.

14. THEY CAN SWIM … SORT OF.

A bald eagle
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There are several videos online—like the one above—that show a bald eagle swimming in the sea, rowing itself to shore with its huge wings. Eagles have hollow bones and fluffy down, so they can float pretty well. But why swim instead of soar? Sometimes, an eagle will swoop down and grab an especially weighty fish, then paddle it to shore to eat.

Note that the announcer in the video above says that the eagle's talons are "locked" on a fish that's too heavy to carry. In fact, those lockable talons are an urban legend.

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Christie's
A Rare Copy of Audubon's Birds of America Could Break Records at Auction
Christie's
Christie's

American artist and naturalist John James Audubon published The Birds of America in the first half of the 19th century, and his massive “double-elephant” folio of life-size bird illustrations remains one of the most ambitious nature books ever produced. On June 14, a rare edition of the four-book set is hitting the auction block, and it's expected to fetch up to $12 million—more than any Audubon book ever sold.

This edition of The Birds of America was owned by the dukes of Portland from around 1839 to 2012. Because it was stored on the shelves of the family's Nottinghamshire, England estate for nearly a century, the set's prints of watercolor drawings have remained remarkably well-preserved.

In 2012, the copy was auctioned off to philanthropist and businessman Carl W. Knobloch, Jr. for nearly $8 million. Knobloch donated the books to the Knobloch Family Foundation (KFF) before his death in 2016. Now, the KFF is sending the books to auction once again. This time, all proceeds of the sale will go to nature conservation.

Set of red leather-bound books.

New York City auction house Christie's describes the set in a listing as "among the finest copies in private hands of this icon of American art, and the finest color-plate book ever produced." Each of the 435 double-elephant folio pages measures 39.5 inches by 26.5 inches, the largest sheets Audubon could get his hands on at the time, and they feature 1037 birds from 500 species. The books are bound in red Moroccan leather with gold detailing on the borders and spines. The four-volume set also comes with the Ornithological Biography, a collection of five books describing the specimens in The Birds of America and their habits.

Christie's estimates the set will sell for $8 million to $12 million when the final bid is placed later this month. To date, the most expensive copy of The Birds of America was a first edition acquired from Sotheby's in London for $11.5 million. That sale also broke the record for the most expensive printed book ever sold at auction, a record held until 2013.

Illustration of American birds.

Illustration of American bird.

Illustration of American birds.

Illustration of American birds.

Illustration of American birds.

All images courtesy of Christie's

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