The Science of Birds - New World and African Parrots

Episode Date: September 8, 2024

In this episode—which is Number 103—we enter the fascinating world of parrots, focusing on species in the family Psittacidae, which includes New World parrots and some African species. We look at key parrot traits like their zygodactyl feet, strong beaks, plumage, and vocalizations.We'll also learn about the remarkable intelligence and social behaviors of parrots, their diversity, and their evolutionary history, tracing their origins back to Gondwana and their eventual spread to South America and Africa.Finally, we look at what psittacid parrots eat and how they breed.~~ Leave me a review using Podchaser ~~Link to this episode on the Science of Birds website Support the show

Not long ago, I was standing on a rocky hillside in Patagonia, the southernmost part of South America. It was morning, and I was surrounded by a dense forest of gnarly birch trees. The air was cool and damp, and just about everything around me was covered in mosses and lichens. Through a gap in the trees, I was looking at an enormous glacier, blazing white in the morning sun. It was less than half a mile away. I could trace the length of it grinding its way through a valley down from the Andes Mountains and crumbling into a milky blue lake. The scenery was jaw-dropping and surreal. I couldn't get over the fact that I was in a forest so close to the face of a glacier. There were birds singing happily around me and some Chilean fire bushes displaying crimson-colored

flowers. And just when I thought the moment couldn't get any more magical, here come the parrots. A noisy flock of austral parakeets flew right in front of me. Their feathers were shades of dull green, yellow, and red. The flock stood out in sharp contrast to the backdrop of the glacier. Landing in some nearby trees, the parakeets chattered and settled in to munch on some berries and leaf buds. I could see them up close. They were adorable, beautiful, and charming.

I couldn't believe how lucky I was to be sharing this experience with these wild parrots, in a place that felt like the edge of the world. Birds make everything better, don't they? That moment in Patagonia was one of my treasured memories of wild parrots. The austral parakeet, anacognathous Faruginaeus, is found further south than any other parrot species in the world. It lives in southern Chile and Argentina. So the word austral in this case is not a reference to Australia. The Latin word australis just means southern.

So austral parakeet is a pretty great name for this bird. To someone like me who's lived his entire life in North America, seeing any parrot species in the wild is a special event. Because, except for a couple of rare exceptions, there are no native parrots in the United States. Europe doesn't have any either. So for many of us, these colorful, noisy birds are symbols of exotic places,

of tropical landscapes far away. Hello and welcome. This is the science of birds. I am your host, Ivan Philipson. The Science of Birds podcast is a lighthearted exploration of bird biology for lifelong learners. This is episode 103. It's all about parrots in the family Cetacity. That's spelled with a silent P, P-S-I-T-A-C-I-D-A-E.

So we're talking about parrots today, you guys. Woo! Show me a person who doesn't love parrots, and I'll show you. you a miserable sourpuss. I mean, come on, you gotta love parrots. Of course, some of you listening right now live in places like Latin America, where seeing wild parrots is more of an everyday kind of thing. Like, no big deal. Maybe you've got a few squawking obnoxiously in your backyard right now. But even if that's your situation, I hope you're excited to learn more about your backyard buddies. The family Cetacity includes all the New World parrots, as well as the African parrots.

Well, some African parrots. Not all of the parrot species in Africa belong to the family's cetacity. Only 12 of them, but I'll explain all that later. In any case, the family we're talking about today includes iconic birds like the gray parrot, Scarlet Macaw, and the monk parakeet. But there are many other parrot species out there in the world. Ornithologists currently recognize three other parrot families, and those include the species in Asia and Australia.

I'll eventually make separate podcast episodes for each of those other parrot families. Anyway, it was about time I did at least one episode on parrots, because, you know, the bird I chose for the science of birds' logo is a parrot. All right, let's get into it. I'm sure you can visualize the typical body structure of a parrot. It's got a relatively large, blocky head, a short neck, shortish legs, and a thick, curved beak. The shapes of the wings and tail vary among species.

Some have rounded, sort of blunt-tipped wings, others have elongated wings with pointy tips. These wing shapes provide different aerodynamic advantages. And, roughly speaking, they're related to the parrot's habitat. Parrots living in dense forests or jungles benefit from having more rounded wings for maneuverability as they fly between tree trunks and branches. Parrots living in open savannas or deserts, on the other hand, benefit from the speed and efficiency of pointed wings. Tail shape and length also vary among species.

Some have short tails with a rounded or squared shape. Other species have long, pointy tails. But as far as I can tell, the connection between tail shape and habitat is not as strong as it is between wing shape and habitat. And since we're talking about parrot tails, we might as well talk about parakeets. The family Cetacity contains birds we call macaws, parrots, and parakeets.

These names don't correspond to any unique evolutionary or genetic lineages within the family. In other words, they don't refer to unique taxonomic groups. Instead, the names macaw, parrot, and parakeet are based on the sizes and shapes of the birds. So parakeets are smaller to medium-sized parrot species that have long, tapered tails. Macaws are large birds with long tails, and everything in between we call a parrot. In the world of pet birds, or aviculture, you come across the word conure, C-O-N-U-R-E. This is a loose term applied to some small species in the family satacity. Connure is sort of synonymous with parakeet. broadly speaking, it's perfectly fine to refer to all the birds in the family's satacity as

parrots. Moving on to the feet of these birds. Parrot feet are pretty cool. If you listened to the last podcast episode, I went on and on about the feet of the common kingfisher. I pointed out that kingfishers have a syndactyl type of foot. Meanwhile, your average songbird has the familiar anisidactyl type of foot. with three toes facing forward and one facing backward.

Parrots have yet another type of toe arrangement. They have two toes facing forward and two facing backward. Ornithologists call this a zygodactal foot. Zygodactal feet have evolved independently in several bird groups, including woodpeckers, cuckus, owls, and parrots. Parrots use their strong zygadactal feet for climbing around in trees. and those feet are also great for manipulating small objects. In fact, parrots are one of the few bird groups capable of using their feet with high dexterity.

They can grip objects tightly and manipulate them with precision. In a typical non-parrot bird, the feet might be used only for immobilizing food, pinning it down, while the bird reaches down with its beak to get at the food. But a parrot can use its foot to hold and move an object the way a human uses. uses their hand. A parrot can lift a seed or piece of fruit up to its beak. So this ability is one superpower that all parrots have. But perhaps the most obvious feature that makes parrots unique is their bill. I mean, it has a super distinct shape, right? So much so that there are other non-parot birds named for the fact that their bills resemble those of parrots. For example,

there's an entire family of songbirds in Asia called parrot bills. And those are in no way close relatives of the real parrots. Among the true parrots, bill shape is pretty uniform. It's strong and curved, with a hooked upper mandible and a robust lower mandible. The upper mandible is also hinged, allowing for greater flexibility in feeding and climbing. Parrots have specialized jaw muscles not found. in other birds, muscles that support a powerful force for biting and chewing, and their tongues are thick and muscular, unlike most other birds. The entire apparatus of beak and tongue and muscles

is a great adaptation for cracking open seeds and nuts and for manipulating objects with precision. And parrot beaks are also beautifully adapted for the important task of biting human fingers and other sensitive appendages. An angry or frustrated parrot can easily lacerate human flesh and draw blood. That's why I don't mess around with parrots. As much as I love these birds, I generally keep my distance

from any supposedly friendly pet parrot I come across. I don't need any spontaneous, involuntary piercings on my ears or lips. No, thanks. Now, I mentioned the beak is used in climbing. The strong mobile beak works like a, a fifth limb for a parrot clambering around in the treetops. This makes me think of how parrots have, through evolution, converged with primates in some ways. Both groups of animals are smart,

social, and capable of manipulating small objects with skill. But primates don't use their mouths for climbing. But what if, though, imagine a human climbing like a parrot. If you were a rock climber on a granite cliff, you would have to pull yourself up by hooking your upper teeth on each handhold. Or I guess they'd be tooth holds? Anyway, in terms of size, the largest species in the family cetacity is the hyacinth macaw, a noderincus hyacinthinus. With a length of 3.3 feet or 1 meter, the hyacinth macaw is actually the largest parrot species in the world. This amazing bird is a rich cobalt blue all over, with bright yellow accents on its face. The smallest members of the family are species in the genus forpus. These are the parrotlets. Most of the nine

species in this genus are about the same size, a little over five inches or 13 centimeters long. Thus the name parrotlet. There are some species in other genera that we also call parrotlets, but the cute little buggers in the genus Forpus are the smallest. All right, let's talk about plumage color. parrots are, of course, famous for being among the most spectacularly, ridiculously colorful birds on the planet. Remember that the family we're talking about today, Satacity, includes all of the New World parrots as well as their close relatives living in Africa. Interestingly, the African species are less colorful on average than the parrots of North and South America. For example, the gray parrot, cetacus erythacus, is an African species.

and it's probably the least colorful bird in the entire family. And yet, it's still quite lovely. Its body color is ashy gray, the face is mostly white, and the tail is an amazing scarlet red. But the typical cetacid species is mostly green, with some accents in red, yellow, blue, and so on. A smaller number of species have bodies that are mostly red, blue, yellow, or brown. The scarlet macaw, for example, has a red body. The dusky parrot is shades of brown with a slaty blue head. And the plumage of the sun parakeet is dominated by yellow and orange.

Overall, sexual dichromatism is not really a thing in this family. Males and females of most species look remarkably similar in terms of their plumage color and patterns. Well, they look similar to human eyes anyway. We have to keep in mind that birds see the world differently. So there could be color differences between males and females of some parrot species that they can see, but that scientists haven't detected yet. In most birds, other than parrots, the red, orange, and yellow pigments in feathers come from the things birds eat, like small crustaceans or fruit.

Those pigments are called carotenoids, and we talked all about this in episode 56 of the podcast. which was about feather colors. But parrots do things differently. As far as I know, they don't use carotenoids in their plumage at all. The brilliant red, orange, and yellow colors of their feathers come from unique pigments called cetacafulvins. The word setacopholvin is spelled again with a silent P. P-S-I-T-A-C-O-F-L-V-I-N.

These pigments are made inside the cells of a parrot, rather than coming from the bird's diet. Sotako-Fulvins are found only in parrots and nowhere else. Despite having all those amazingly bright colors, most parrots in the family's satacity don't show them off in elaborate ways. I mean, think about the flamboyant courtship displays made by birds in the pheasant family. That includes peacocks, right? The Indian pea-fowl? Those guys have colorful feathers and they really flaunt what they got. Our parrots, in comparison, don't put on too much of a show. They can't be bothered to dance energetically while fanning out their feathers in spectacular displays. Parrots are more like, this is me, take it or leave it. I don't care.

But there's at least one species that stands out as a nonconformist. It's the red fan parrot, Duraptius Axipotrinus. It lives in the Amazon basin, and it's the only species in the genus Duraptius. Both male and female red fan parrots have these extra long feathers on their napes, in other words on the back of their necks. The feathers are maroon with electric blue tips. They're gorgeous. Normally these feathers lay flat against the bird's neck, just like on every other parrot. But during courtship, a red fan parrot makes a special display. It erects its nape feathers to form a colorful fan around its head. It looks like a psychedelic lion's mane or something. Or if you could glue a few horns onto one of these parrots,

it would look sort of like a little triceratops dinosaur, what with the beak and that neck fan. The red fan parrot is so wacky that it almost qualifies for getting a weirdo alert. Almost. But stick around because there are even weirder parrots out there. Anyway, I'll put a photo of the red fan parrot in the show notes for this episode, so you can check it out on the Science of Birds' website. Okay, so we've talked about what cetaceid parrots look like. Now let's consider a couple of their key behavioral traits. For starters, these are super smart birds. High intelligence is one of their claims to fame. For example, we talked about the gray parrot. in episode 25 of the podcast, which was all about avian intelligence. This is not only one of the

smartest birds, it's one of the smartest animals on the planet, period. Gray parrots in captivity have learned over 100 words to communicate with humans, using words to describe shapes, colors, types of food, and so on. They can even count objects and form simple sentences. The gray parrot is thought to be at least as intelligent as a five-year-old. old human. Besides being intelligent, parrots in this family tend to be highly social. Many species feed together in flocks, and they roost together at night in trees. Being so smart and social, parrots show a wide range of complex behaviors as they interact with each other. To see some of these behaviors, just go to YouTube and watch a few of the countless videos of pet parrots as they

interact with each other or with their humans. I have to admit, that I'm a total sucker for all those goofy, adorable parrots on YouTube, dancing, singing, and generally causing mayhem. They're hilarious. And you know, if I've learned anything about parrot behavior from watching Disney movies, it's that they make great advisors or sidekicks, whether you're a pirate, an anthropomorphic lion monarch, or an evil Arabian wizard. You got to get yourself a parrot, so it can sit on your shoulder and tell you what you should or should If I had a parrot sidekick on my shoulder, it would have to constantly tell me to stop scrolling mindlessly on my phone and get back to work. Or maybe it would just bite off a piece

of my ear and then there would be blood everywhere. Who knows? In any case, it's time to talk about the sounds that these birds make, their vocalizations. As we all know, cetacid parrots in captivity have an amazing talent for mimicking sounds. so much so that another definition for the word parrot is to repeat mindlessly. We can teach these birds to say all sorts of fun things. For example, parrots will gleefully and loudly repeat inappropriate words and phrases when your in-laws come over for Christmas dinner. But surprisingly, wild parrots don't seem to use their mimicking abilities all that much.

Instead, they make loud, harsh squawks and screeches. They don't really sing or make sounds we would otherwise call melodic. And did I mention these birds are loud? So loud. You know, when I make podcast episodes like this, I search the internet for bird calls and songs to play for you in the episode. Well, with these parrots, I'd sometimes hit play to listen to one of their calls, and then my eardrums would get blasted by this god-awful strident noise.

I was like, Ah! Make it stop! Make it stop! Then I had to rip my headphones off or else I'd go deaf. What might explain the mimicking behavior in parrots, to some extent, is the fact that they have to learn their vocal sounds from other birds. Passerine birds and hummingbirds also have to learn their vocalizations. But most other birds just rely on instinct. Each parrot species has a repertoire of calls, and each call communicates something different. Calls can sometimes be divided into those meant to communicate over long distances and those that are for short distances. For example, there was a study of yellow-faced parrots in Brazil.

The researchers ended up identifying seven unique calls in this species. There's the long-range flight call, the long-range alarm call, the long-range congregation call, a short-range and a long-range agonistic call, a short-range sentinel call, a short-range alarm call. Some parrot species may have dozens of distinct call types. All right, it's time to actually listen to some of these sounds. Make sure you have your headphones on tight and that your volume is cranked to maximum. Nope, nope, I'm just kidding, kidding.

I'll do my best to keep these sounds from being too harsh, but I can only do so much. So you've been warned. First up, let's go to Brazil and listen to some indigo macaws, also known as Lear's Macaws. These large parrots are an almost metallic blue all over, with some yellow around the eye and lower beak. They have relatively deep resonant calls. How about another species of macaw from a different genus? Here are some blue and yellow macaws in Peru. For contrast, let's listen to the cute, squeaky sounds of

a green-rumped parrotlet, forpus passorinus. Remember that these parrotlets are among the teeny tini-tiniest members of the family. They're so small. This recording was made in Colombia. Next up, we have the raucous sound of some blue-headed parrots in Ecuador.

Moving over into the Caribbean, here's a black-billed Amazon in Jamaica. It's making a lower guttural call. Parrot chicks in the nest make distinct begging calls, desperately trying to get their parents to feed them. Here's the begging calls of some scaly-headed parrots, recorded in Bolivia. Wow, those scaly-headed parrot chicks sound like a dog's squeaky chew toy, don't they? Or like a clown horn or something? Pretty obnoxious. Would somebody please feed these baby parrots so we can all get a moment of peace? I'm trying to record a podcast here.

Okay, the last recording I have for you is a species from Africa. So far we've heard sounds only from New World species. So here's our wicked smart friend, the gray parrot, making a few different calls in an African forest. We'll move on. now to discuss the diversity, distribution, and habitats of parrots in the family satacity. So we've got the family satacity. And moving up one level of classification, we see that this family belongs in the order satasiformis. All of the world's parrots belong in the order satasiformis. This

order includes the four families I briefly touched on earlier, including the Old World Parrots, Cockatoo's, and New Zealand Parrots. Some ornithologists recognize a fifth parrot family that includes a handful of wacky species living in the region around Madagascar and on the island of New Guinea. Until about a decade ago, the New World Parrot family that we're talking about today was merged with the Old World Parrot family. All of those species were under one big tent, so to speak, the tent named Cittacity. But now the old world species are in their own tent, their own family, called Citeculody. You got that? It's a bit confusing. New world parrots, plus a few in Africa, belong to the family Cetacity. Old world parrots are in the family

Citaculidi. And these two groups are each other's closest relatives. That root word with a Silent P comes from cetacus, P-S-I-T-A-C-U-S, which in Latin means, well, exactly what you would guess. It means parrot. Within the family cetacea-de, there are two distinct sub-divisions, representing unique evolutionary branches. These are the sub-families, erini, and cetaceae. There's a clear geographic division between the two. Birds in the sub-family erronee include all the species. in the New World, in North and South America.

Meanwhile, the sub-family Cetassany comprises all of the African species. And there are just 12 species in Africa, and they're divided into two genera. All of them live south of the Sahara Desert. The highest diversity in Africa is concentrated in the equatorial region, but one species, the Cape Parrot,

is found at the southern tip of the continent. The New World sub-family, Arani, has 160, 60 species, and these are divided into 34 genera. The genera with the most diversity, the greatest number of species, include the genus Amazona with 30 species, and the genus Pirhura, with 23. Of the 17 species that we call macaws, nine are in the genus Aura, spelled A-R-A. New World parrots are found all over South and Central America, and over 20 species are found in Mexico. So, like their human counterparts, you'd think that there must be thousands of parrots migrating

into the U.S. every year, hoping to pursue the American dream. But there must be a big warning sign on the U.S.-Mexico border or something that reads, No parrots allowed. Because here in the U.S., it's kind of a desolate wasteland when it comes to native parrot diversity. But once upon a time, two parrot species were native to the United States, the Carolina parakeet and the thick-billed parrot. Sadly, the Carolina parakeet is extinct. The thick-billed parrot still exists, thankfully,

but it doesn't have any populations remaining in the U.S. I'll talk a little more about these two species later. Then we have the case of the green parakeet, Sitakera holocloris. This species lives in parts of Mexico and Central America. As far as we know, there's no historical evidence of green. parakeets living in the U.S.? Well, prior to 1969, that is. Because 1969 is the year green parakeets were first recorded in South Texas. There are now established year-round populations of this

species in Texas. But the question from the beginning has been, where did these green parakeets come from? Did they arrive from Mexico on their own? Laughing in cheerful disregard at the no parrots allowed sign as they flew across the border? Or, did they originate as escaped pets in the cities of the lower Rio Grande Valley? I don't think scientists have a definitive answer yet, but my understanding is that the green parakeet population in South Texas is most likely the result of both natural range expansion from Mexico and introductions from escaped captive birds. But the exact proportions and contributions of these two sources are unclear. Now a moment ago, I said the U.S. is a

desolate wasteland when it comes to native parrot diversity. But it's a whole different story when you consider non-native parrots. There are established, naturalized populations of over 20 non-native parrot species in the U.S. The hotspots are Florida, Southern California, and the San Francisco Bay Area. And there are monk parakeets breeding as far north as New York City and across the pond in London, which is crazy. Monk parakeets are native to Argentina. All of these non-native birds in the U.S. and elsewhere are the descendants of captive birds

that either escaped or were set free. This strange phenomenon is so widespread that there's a book with the title, Naturalized Parrots of the World, Distribution Ecology and Impacts of the World's Most Colorful Colonizers. And speaking of colonizing and what not, birds in the family Cetacity are not known for being long-distance migrants. They might fly around over fairly large distances in their home ranges as they search for food, but they don't make major seasonal movements between breeding and non-breeding locations. At least that's true for most species. Most of them are resident birds. Now, what about habitat? Cetacid parrots are mostly our

arboreal. They nest and forage in trees. The 172 species in the New World and Africa exploit a wide variety of forest and woodland habitats. The tropical forests of the Amazon Basin and the eastern slopes of the Andes support the highest number of species. A smaller number of species make their living in open habitats, like savannah, but they still depend on there being some trees around, because birds in this family nest in tree cavities. Only a few species have adapted to life in more arid environments that lack trees. For example, there's the yellow-faced parrotlet found in only one valley in the Peruvian Andes. These little buggers live in a desert scrub habitat with tall cactuses,

and they nest in rocky crevices instead of trees. Weirdo alert. Weirdo alert. Move over red fan parrot. There's a new weirdo in town. It's the bald parrot, Pyrillia Arantio Cephala. This bizarre bird lives in the heart of the Amazon, in Brazil. It's mostly green all over, but with blue accents on the belly and tail. But yeah, it's basically bald from the neck up. The bright orange skin on its head is bare, except for some sparse, hair-like bristle feathers. So yeah, as you might imagine, these are not the most attractive parrots. As you're flipping through your field guide to the birds of Brazil, you come to the page with a

bald parrot and you're like, ah, what is that? Hopefully bald parrots have great personalities to compensate for the shortcomings in their appearance. The other common name for the species is orange-headed parrot. But given that naked vulture-like head, maybe a better common name would be the vulturine parrot. Problem is, that name is already taken. The bald parrot's closest relative is the vulturine parrot, perilia vulturina. It's also kind of weird and has a lot of bare skin on its face. So get this. Until about 20 years ago, ornithologists didn't know that the bald parrot existed. But they did know about vulturine parrots. Ornithologists figured out that juvenile vulturine parrots had naked orange heads and that the young birds stick together flying

around in flocks. But that turned out to be false. Because in a study published in 2002, researchers discovered that those bald birds are actually sexually mature. They're adults, not juveniles. And they are not vulturine parrots. They're a species that until this 2002 study had gone undiscovered. And that is how the world was introduced to our wonderful weirdo, the bald parrot. We used to think they were just juvenile vulturine parrots, but now we know they're their own species. Over 20 years after its discovery, there's still a lot we don't know about the natural history of this bird. And it seems ornithologists have no idea what bald parrots eat or how they breed. When I scoured the internet, I couldn't even find any good

photos of them. The photos are all blurry and grainy, as though the bald parrot is some sort of crypto-zoological creature like the Jersey Devil or Bigfoot. What we do know about bald parrots is that they're threatened by habitat destruction through logging. The very rough estimate for the total population size of the bald parrot is 10,000. And that's a very rough estimate. And that's That's not very large, all things considered. More research is needed so we can understand and help these birds. So if you're an adventurous grad student and you're looking for a bird to study, get yourself a canoe and some bug spray and start paddling up the Amazon River.

Go find those bald parrots. family satacity. Well, through decades of research, ornithologists and paleontologists have uncovered an epic tale, one that stretches way back to the age of the dinosaurs, the Mesozoic era. Scientists have been able to reconstruct the long history of parrots using a combination of genetic data, fossils, and paleogeography. There's still a lot of uncertainty and some disagreement, but here's the basic story, as I understand it. Primeval parrots were flapping around on the supercontinent of Gondwana as tectonic forces were breaking it up throughout the Jurassic and Cretaceous periods.

We're talking 160 to 66 million years ago. But the common ancestor of all modern parrots probably lived in what is now Australasia. And that would be after the continents of Africa and India had already gone their own ways. Australia finally broke away from Antarctica, which was still attached to South America, roughly 55 to 45 million years ago. Imagine parrots sort of riding around on these big continental chunks, these fragments of what used to be Gondwana. So Australia breaks away, and that leads to a major evolutionary split in the parrots.

Some stayed in Australia, the rest were isolated in Antarctica. And in case you're wondering, up to this point, point in our story, Antarctica was covered in lush vegetation. It was a lot warmer than it is today and was a perfectly suitable home for parrots. Around 30 million years ago, South America and Antarctica split apart. But they were still close enough that birds could fly between them across the newly forming Drake Passage. At the same time, 30 million years ago, things started to get really Chile in Antarctica. Glaciers formed and ice sheets spread across the continent. That may have been what forced parrots north and west into South America. But some parrots fleeing Antarctica went another direction.

They went north and east to Africa. They may have been able to disperse to Africa one step at a time across a chain of islands in the Atlantic Ocean that no longer exists. So that's where we get the evolutionary division between the two sub-families, right? The lineage that became the Aranese sub-family left Antarctica and ended up in South America, and the Cetassanee lineage is the one that got established in Africa. Again, that split seems to have happened around 30 million years ago. The Aranese sub-family underwent a significant diversification in South America starting around 27 to 23 million years ago. This group eventually expanded its range into North America and the Caribbean. This last stage of expansion was mostly after the formation of the Isthmus of Panama,

which happened around 5 million years ago. So there you go. Parrots in the family Cetacity originated in Australia. They got stuck in Antarctica when it separated from Australia. Then when Antarctica began to transform into the frozen hellscape that it is today, the parrots were like, Peace out, we got to go north, yo, where the palm trees are. Forget all this ice and stuff.

Some flew to South America, the rest went to Africa. And that explains the puzzling connection between parrots in South America and Africa. It seems reasonable to imagine that 30 million years ago, the first parrots arriving in South America landed somewhere in Patagonia. So maybe close to where I had my lovely moment with the glacier and those austral parakeets.

Parrots in general are among the most threatened types of birds on the planet. About 30% of the species in the family cetacity have been placed in one threat category or another by the International Union for the Conservation of Nature, the IUCN. For example, seven species are in the critically endangible. endangered category. The biggest threats to these birds historically have been habitat loss and the capture of wild birds for the international pet trade. But at least in parts of Latin America, capture for the local pet trade has become a major driver of recent declines. Following the enactment of the Wild Bird Conservation Act in 1992, importing wild-caught parrots became illegal in the

United States. Similarly, the European wild bird trade ban made it illegal to import wild caught birds into the European Union. But wild birds are still smuggled illegally all over the place. The topic of keeping parrots as pets and the trade of these birds, both legal and illegal, all of that, that's a big, complex topic, and I'll leave that for a future podcast episode. So for the major threats, you've got habitat destruction and the pet trade. In some cases, parrots have been persecuted directly by humans. The monk parakeet, for example, was declared an agricultural pest by the government of Argentina back in 1935.

One species in this family, Spix's macaw, is extinct in the wild. Until recently, the only surviving individuals were all captive birds. In episode 84 of the podcast, I talked at length about the recent effort to reintroduce Spix's Macaw into the wilds of Brazil. The program is facing major challenges, so it's still uncertain if this beautiful blue parrot will have a self-sustaining wild population again. Let's hope so. Because we don't want Spix's Maccaw to end up like the Martinique parrot, the Guadalupe Parrot, the Guadalupe Parichite, the Cuban Maccaw and the Carriquette, the Cuban Maccah, and the Carriarche. Carolina parakeet. All five of those species are extinct, gone forever, because of people, of course. And the glaucus macaw, another large blue parrot, might also be extinct already. It's uncertain.

Once upon a time, the Carolina parakeet, conioropsis Carolinensis, was the most widespread parrot species north of Mexico. It had a yellow head, orange face, and green body. No other member of the family satiret. Cassidy was found so far north. In the U.S., parakeets lived in the east, the Midwest, and the plain states as far west as Colorado. They flew around in flocks that could number in the hundreds. Their habitat was old-growth deciduous forest in swamps and along rivers. I planned to do an entire episode on the Carolina Parakeet, so I won't say much more right now. But what caused its extinction seems to have been a combination of deforestation and hunting. People shot the birds to collect their colorful feathers, and because farmers saw them as pests that fed on crop plants.

Earlier, I also mentioned the thick-billed parrot. That was the other parrot species that was native to the U.S. These birds used to live in the high-elevation pine forests of Arizona and New Mexico. Their diet is mostly seeds from pine cones. The last time these birds were seen in the U.S. was around the middle of the last century. Apparently, the cause of the thick-billed parrots extirpation was that people just shot them all, shot them illegally. These birds are gregarious, noisy, and relatively large, so I guess that made them easy targets for trigger-happy idiots with guns. Conservationists tried to reintroduce thick-billed parrots to Arizona back in the 1980s, but sadly the program failed.

The good news is that they're going to try again. I really hope it works this time around. As I've said before, Southeast Arizona is my favorite place to go birding in the U.S. It would be amazing if someday we can see wild, thick-billed parrots flying among the pine trees in the mountains of Arizona. New World and African parrots feed on other things besides human fingers and earloor. Their primary diet in the wild is fruit and seeds.

Many of them also eat buds, flowers, leaves, and sometimes even bark. And some species will snack on insect larvae, like grubs. The Scarlet Macaw, for example, eats the large seeds of a long list of tropical tree species in Central and South America. Birds in this family aren't doing their food plants any favors. They don't help the trees or other plants disperse, by eating the seeds whole, then pooping them out somewhere else in the forest, where the seeds germinate and the circle of life continues.

No, cetacids are not seed dispersers, they're seed predators. They crush the seeds and digest them. That distinct curved parrot bill is incredibly strong and sharp. It's the perfect tool for breaking open the shells of large, tough nuts. And those zygodactal feet allow a parrot to grip and manipulate, fruits and nuts while feeding. They may not be long-distance migrants, but our parrots are still highly mobile critters. They fly all over the place in their quest for tasty treats. The availability of fruit and nuts is haphazard across the forested landscapes of Latin America and Africa.

Parrots may need to fly miles and miles to reach wherever the food happens to be on a given day. A typical day for a parrot involves waking up in a communal roost. It slept while perched near dozens or hundreds of its buddies on the branches of a tree overnight. Early in the morning, they all wake up and make a cacophony of squawks and screeches. Our parrot then takes off with a small flock. They forage and feed together for a few hours, then it's siesta time, or time to prine and horse around. The flock returns to their roost in the evening, making a lot of noise as they arrive. You've probably heard about how many parrots visit clay licks.

This behavior is especially common in parts of the Amazon basin, including Peru, Ecuador, and Brazil. The phenomenon is most famously observed along the riverbanks of the Amazon and its tributaries, where large flocks of parrots, including macaws, gather to consume clay from exposed cliffs. Clay licks are also known as colpas, or or baheros. These birds scarfing down beakfuls of clay is another example of something I've talked about before, and that's geophagy. In other words, eating dirt or rocks. So what's going on here? Eating clay sounds kind of gross, right? So why do parrots do it? Ornithologists think there are a

couple of reasons. First, it probably helps the birds supplement their diet with salt and other essential minerals. Second, clay in the digestive system can absorb poisonous substances that the parrots eat. Many plants produce poison to protect their seeds from being eaten, but parrots get around this chemical defense by eating clay. The superpower of being able to eat poisonous seeds might help parrots avoid competition with other seed predators. For example, there was a study conducted on the red and green macaw in Venezuela. There's a monkey called the bearded sake that overlaps with the macaw in its habitat and diet. The bird and the monkey are both great at cracking open nuts with super hard shells. On some tree species, the red and green macaws eat the seeds

before they're ripe. At that stage, the seeds are toxic. But the bearded sake monkeys eat the seeds only after they've ripened up, when they're far less toxic. So, as long as the macaws have access to a clay lick nearby, their tolerance for poison allows them to avoid fighting with the monkeys over seeds. Of course, they may still fight over other things, because, come on, we're talking about parrots versus monkeys here, two of the world's smartest and most mischievous animals. If someone walked up to me and said,

Hey, do you want to go see parrots versus monkeys? I'd say, oh my God, yes. I don't care how much it costs. I didn't realize it till just now, but I've never wanted to see anything so badly in my life. Now, all joking aside, sometimes parrots versus monkeys isn't such a hilarious situation. It can be a matter of life and death, because monkeys are one of the major predators that raid parrot nests for eggs and chicks. Other arboreal mammals and snakes are also nest predators. A dotho. Adult parrots fall victim to raptors like harpy eagles, and perhaps the occasional large snake. Moving on, let's look at breeding in parrots.

Generally speaking, these are monogamous birds that stay paired up for a long time. A pair will stick together through the seasons and maintain their bond for years and years. Some larger species like macaws have lifelong pair bonds. I've pointed out before that many bird species around the world are socially monogamous, but not necessarily sexually monogamous. A mated pair might spend a lot of time together and raise a family together. Socially, to the outside observer, the two birds seem like they're in love and 100% faithful to each other. But they may not be sexually monogamous.

one or both of them might occasionally mate with other birds on the side. Among all birds, being strictly monogamous in both senses is rare. But it seems ornithologists still don't know where parrots fall on this spectrum. They don't know how common it is for parrots to be both socially and sexually monogamous. However, there was one study in 2002 where researchers used DNA fingerprinting to look at paternity in the burrowing parakeet, Sayano Laceous Patagonus. In 49 parakeet families over two years, the researchers found no evidence of any extra pair paternity. In other words, in the 49 families, all the chicks in a brood belonged to the

male and female that raised them. So the burrowing parakeet may be a strictly monogamous species. Is this the norm for cetacid parrots, or an exception? Who knows? A lot more research is need. to answer that question. As you might guess, some courtship behaviors are involved when parrot parents pair up. Geez, good thing I have a pop filter on my microphone. Parrot parents pair up. Peter Piper picked a parrot. But anyway, courtship. Usually it's the male who shows off for a female.

His display involves some combination of strutting, head bobbing, and vocalizing. Another behavior often associated with courtship is eye-pinning or eye-blazing. This is where a parrot rapidly contracts and expands its pupils. When the pupils shrink, more of the iris color is revealed, and vice versa. Eye-pinning is not exclusive to courtship, but is often observed in that context, where it may be a sign of interest or excitement toward a potential mate. The rapid change in pupil size is thought to be a non-verbal form of communication, signaling the bird's emotional state. And apparently that emotional state isn't always a

happy one. Here's a quote from the book, parrots for dummies. A parrot whose pupils are pinning in and out is excited and may be in bite mode. Bight mode? See, this is why I don't mess with parrots. If there's a parrot near me and I see its pupils start pinning, how do I know what's going on? Is the bird happy and excited to see me? Or is it like, you better back up, son, I'm in bite mode. You step one foot closer and I'll rip your nose off. In the wild, parrots may go into bite mode while defending their territory. And by territory, we're usually talking about just the area immediately around the nest site.

These birds don't generally defend large territories. Almost all parrots in the family Cetacity make their nests in cavities, and this is true for most species in the other three parrot families as well. Usually a nest cavity is a pre-existing hole in a tree. Parrots might modify or clean out the cavity by removing loose debris, but they rarely create the cavity themselves. A nest cavity might be used by the same pair year after year. And that's why trees are so important. They provide the essential nesting sites for parrots. A healthy natural forest has plenty of large, old trees with natural cavities. There are a couple of outlier species in the family that don't

use trees as nesting sites. The burrowing parakeet, you know, the one that seems to be strictly monogamous, excavates its own cavities in cliffs. Impressively, nest burrows up to three meters deep are often dug into limestone or sandstone. The burrow, Burrows often end up creating a little labyrinth of tunnels that would make David Bowie proud. Then we have the Monk Parakeet. This is another South American species whose range overlaps that of the burrowing parakeet in Patagonia. Monk parakeets are unique because instead of using nest cavities like other parrots, they build stick nests on their own.

Or they build a nest with their buddies, because monk parakeets often nest in colonies. The stick nests can be enormous with dozens or hundreds of individual chambers inside. Once a pair of parrots has selected and prepared their nest site, it's time to lay some eggs. Small species have larger clutches of up to 11 eggs, while big parrots like macaws have smaller clutches, more like one to three eggs. The female incubates the eggs while the male brings her food. Incubation is between two weeks and a month. and it begins as soon as the first egg is laid. That means that these parrots have asynchronous hatching.

The chicks hatch at different times in the order the eggs were laid. So there are some size differences among the chicks in a single brood. And those differences can be pretty dramatic. For example, in the green-rumped parrot lit in Venezuela, the oldest chick in a typical brood of eight might weigh 15 grams when it's 12 days old. but its youngest sibling, who just hatched, can be ten times smaller, weighing just 1.8 grams. Unfortunately for the youngest chicks in a brood like that, the chances of survival are often relatively low, especially when food resources are limited.

The older, larger chicks out-compete their siblings, wolfing down more than their fair share of the food. And that food, by the way, is whatever a parent-parate regurgitates, into the gaping beak of a hungry chick. Usually a mash of partially digested fruit, seeds, and nuts. Yummy! The chicks are altricial. That means they're born helpless, right? They're mostly naked, their eyes are closed,

and they can't feed themselves or keep themselves warm. Both parents care for their helpless babies. At first, it's only the male that brings food to the nest, while mom keeps the chicks warm. But once the chicks have some feathers, she may also leave the nest to make feeding forays. Young parrots mature slowly compared to many other birds. Maybe that's because they're so smart

and their brains need time to develop and maybe because they have to learn many of their vocalizations and behaviors. Chicks might stay in the nest for over two months before they venture out into the real world. Parental care continues for up to a year in some large species like macaws. For many parrots, especially those larger ones, it takes more than a year to fully mature.

In general, cetacids are long-lived birds. Most of what we know about their lifespans comes from captive individuals. Some large species like the gray parrot, macaws, and birds in the genus Amazona have lived for over 80 years in captivity. So if you're thinking about getting a pet parrot, you better be ready for a lifelong commitment. It ain't like a dog that'll kick the bucket after like 12 years. But smaller parrot species have shorter lives, more like 15 to 20 years. But still, that's pretty long when compared to the lifespans of similarly sized birds in other non-parate families. This might be the first Science of Birds podcast episode about parrots, but it certainly.

certainly won't be the last. We've got three more parrot families to cover and many individual species worthy of their own episodes. For me, seeing any wild parrot is a thrill. They're such beautiful, charismatic, and fascinating birds. That's why I chose a parrot for the Science of Birds logo. They're just cool. And you know, I can imagine a science fiction scenario in the future where humans go extinct. And then a new species rises up to replace us. to take over the world and stuff. Candidates include highly intelligent critters like octopuses, dolphins, elephants, corvids, and parrots. Parrots are not only smart like us, they're highly social and vocal,

and they've got those zygodactal feet that work sort of like hands. So who knows? Maybe someday parrots will be the ones building skyscrapers, playing basketball, and making podcasts. Forget about the planet of the apes. I'm betting on the planet of the parrots. Thanks so much for listening today, and I hope you enjoyed the episode. I wonder if you have had the good fortune of seeing some wild parrots. Or maybe you have a pet parrot.

Or perhaps you're an evil Arabian wizard with a parrot sidekick. In any case, I hope this episode helped you. learn some new things about these awesome birds. All this sciencey goodness is able to reach your ear holes because of the generosity of my supporters on Patreon. So let's thank them for helping me keep this show going. And I want to give a big welcome shout out to the newest members of my Patreon community. Michelle Wilfong Oliphant, Elena Bossert, Oscar Herrero, Andrea Carpio, Matthew Schultz, and Michael Day. Thank you all. all so much for stepping in to support the podcast.

Joining the community is super easy. You can check out the details by clicking the support the show link near the bottom of the show notes, or you can just go over to patreon.com slash science of birds. My email address is Ivan at scienceofbirds.com if there's something you'd like to share with me. Maybe you have a thought about the podcast, or you want to tell me what it means

when the pupils in your eyes start pinning in and out. out. Does it mean you're going into bite mode? Breakdancing mode? Airplane mode? This is episode 103. You can check out the show notes for the episode along with some curated photos of parrots that I talked about today on the Science of Birds website, scienceofbirds.com. I'm Ivan Philipson. Thank you so much and I'll catch you in the next episode. Cheers. Thank you.