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Anusuya Chinsamy Sister: In other words, it is quite different from the bird that we commonly think of as sitting on a bird feeder. You know, definitely not that kind of bird.
Flora Lichtmann: I’m Flora Lichtmann from Scientific American. science fast. Today is episode 3 of the 4-part really big bird fascination. We continue our massive goose chase.
Chinsamy Turan: I love talking about these big birds. Because, as you know, most people think of an ostrich and think it’s big. But in fact they were once real giants.
Lichtmann: Anusuya Chinsamy Turan, a paleontologist at the University of Cape Town, South Africa. She’s talking about Dromornithidae. That’s their scientific name. But in the world of big birds, you’ll hear them called thunderbirds.
Chinsamy Turan: And I think the name Thunderbird is really great. Because you can immediately understand that these really big animals are coming.
Lichtmann: Thunderbirds live in Australia and have been active for a long time. The earliest members of this group predate him some 50 million years, and one species persisted until about 40,000 years ago. And there was one Thunderbird that thundered louder than the others.
Chinsamy Turan: The largest is called Thunderbird Dromornis stiltoni. And they have been known since the Late Miocene, about 8 million years ago.
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Lichtmann: Here’s what to image:
Chinsamy Turan: It’s like an overgrown ostrich. Think of the ostrich. It’s a little big and has a big beak. Bones would have been heavier, bulkier, more robust…
Lichtmann: But for example many Bigger and stronger.
Trevor Worty: absolutely. They were some of the largest birds on Earth and ever existed on Earth.
Lichtmann: I’m Trevor Worthy, a paleontologist and thunderbird expert.
Worth it: They weigh a whopping 1,300 pounds, which is a whopping 10 times that of humans.
Lichtmann: A bird the size of a cow.
Worth it: yes.
Lichtmann: They were… huge in almost every way.
Worth it: They have no discernible wings. The bit sticking out of the side of the body is 4 inches. Wings are not damaged.
Lichtmann: they are not flying The closest living relatives are ducks and geese. And that’s another thing you can imagine – giant geese roaming across lush landscapes – eight million years ago Australia was greener – eating plants and fruit. Trevor says the Thunderbird’s vegetarian diet may explain some of its size.
Worth it: you can grow You can have great guts. And you can eat a lot of garbage. So if you can eat a lot of poor quality food, that’s one way to live in the environment.
Lichtmann: Their large bodies probably helped them in other ways as well. Anusuya again.
Chinsamy Turan: Their body size probably evolved in response to the context of other things around them at the time. Australia had these possums. There are marsupial lions like this, and I suspect they could have escaped predation if they were bigger.
Lichtmann: Too big to eat.
Chinsamy Turan: yes. Otherwise, dealing with them is too troublesome. You know, you would rather pursue the smaller things, the things that do you no harm. Because, while we know that ostriches are certainly not predators, ostriches can do considerable damage to attacking animals just by kicking them.
Lichtmann: And if it’s a goose mate, we all know how terrifying geese can be.
Chinsamy Turan: yes. As you know, I had a friend who was attacked by a goose earlier this year. Believe it or not, she had to be hospitalized because a goose literally came out of nowhere.
Lichtmann: Imagine if that goose weighed 1,300 pounds.
Chinsamy Turan: that’s right. that’s right.
Lichtmann: But how did they get so big? That’s what Anusuya wanted to understand. To explore her question further, she took a very thin piece of Thunderbird bone and examined it under a microscope.
Chinsamy Turan:. This is interesting because it tells how the bones were deposited. So you know the growth rate.
Lichtmann: Bone has annual rings as it grows. Like tree rings…
Chinsamy Turan: There is a white band that indicates good seasonal growth, followed by a growth line that indicates that growth has stopped for a period of time, and then growth resumes. Therefore, just like the rings of a tree, the number of rings can be counted, the age of an animal can be determined, and the time taken for an animal to grow to adult body size can be determined. I can.
Lichtmann: The Bone Ring method is like a feather for Anusuya. She developed this method during her doctoral fledgling. A student working on a dinosaur. And when she applied the method to this giant Thunderbird, she discovered…
Chinsamy Turan: These birds lived in slow lanes. The bones show a growth cycle, suggesting that it took about 15 years to reach adult body size. And this is a really long time compared to modern birds, which grow very quickly.
Lichtmann: And it took them years, too, according to the data, before they had children.
Anusuya and Trevor say this gives some insight as to why these birds don’t exist today.
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If life is easy, i.e. enough food and not too much pressure from predators, they can grow slowly and have babies. But when life gets tough, this can be a more risky strategy. And life got tough for the Thunderbirds. After 8 million years ago, Australia became drier.And then the giant D. Startoni Disappear. Humans arrived in Australia about 50,000 years ago, but soon after every species Totally Thunderbird.
Worth it: Having a life strategy in the slow lane didn’t make it any easier to deal with something new in an environment that took away many young people.
Lichtmann: This theory is supported by another bird story. Consider the emus, another large bird that lived alongside the thunderbird.
Worth it: In contrast, emus grow to full body size in 14 months and breed soon thereafter.
Lichtmann: And the Thunderbird went extinct, but the Emu survived.
Chinsamy Turan: Their extremely fast growth rate allows them to survive, reach adult size very quickly, reproduce very quickly, and quickly recover their numbers.
Lichtmann: And that’s something to think about.
Because many of the birds are on feeders, fluttering around town, pooping on cars, and living in the passing lane. They grow quickly and have babies early. And in an uncertain world full of two-legged jerks that make life difficult for other animals, this strategy has its advantages.
Chinsamy Turan: So when we look at pigeons and robins, I think we need to understand that they are the end product of a long evolutionary history, and that there were many other forms before them. And I think giant birds are also part of the evolutionary history of all the modern birds we see today.
Lichtmann: next Quick science: When big birds become ax killers.
Federico Desgrange: Frightened birds do not follow the general rules of birds.They use their beaks as axes to kill their prey
Lichtmann: That sounds scary.
Degrange: Well, that’s why they are terror birds.
Lichtmann: You heard part 3 of the 4-part series science fast Really fascinated by big birds.
science fast Produced by Jeff DelViscio, Tulika Bose and Kelso Harper. Our theme music was composed by Dominic Smith.
don’t forget to subscribe science fast Get podcasts anywhere. For more scientific news, visit ScientificAmerican.com.
for science fast–I’m Flora Lichtmann.
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