The Science of Birds - What We Learned About Birds in 2025

Episode Date: January 3, 2026

👕 Bird Merch —  Get yourself some bird shirts!~~~Episode 127 of The Science of Birds is Ivan Phillipsen’s annual review of fascinating ornithology stories from 2025. Learn about a handful of standout studies that deepened what we know about birds, from major developments in global bird taxonomy to surprising insights about behavior, evolution, and conservation.After a few featured deeper dives, the episode shifts into a rapid-fire “Speed Round,” spotlighting a flurry of bite-sized discoveries.The episode wraps with some notable 2025 taxonomy updates (splits, lumps, and reclassifications) and a brief personal year-in-review for Ivan and the podcast itself.Link to this episode on the Science of Birds websiteEarlham College - A fantastic place to get an education, especially if you love birdsSupport the show

Sponsoring the podcast this month is Erlem College. If you or a young birder in your life is thinking about college, you want to put Erlem on your list. Erlum is a liberal arts and sciences college in Richmond, Indiana, and it's a fantastic place to get an education, especially if you love birds and the natural world. The campus sits on a major migration flyway, and it also includes bird habitats like forests, prairies and wetlands. As a student at Erlem College, you'll learn from professors who are truly passionate about ornithology, including an endowed chair, meaning there's a professor dedicated specifically to the study of birds. You'll take classes like field ornithology, conservation

biology, and animal behavior, and join a tight-knit birding community. Erlum's research and travel opportunities are exceptional. Students work on grassland bird conservation in Iowa, conduct research in places like Peru and Papua New Guinea, and join fully funded field courses to places like Namibia. Plus, every student gets up to $5,000 for an internship or research experience through Erlem's four-year college-to-career program called The Epic Journey. Whether you love the outdoors or you're thinking about a career as an ornithologist, I think you really should check out Erlham College.

I put a link in the show notes if you want to learn more, or you can visit Erlem.edu slash birding. Erlem is spelled E-A-R-L-H-A-M, Erlem. dot edu-S-Birding. And thanks to Erlom College for sponsoring the podcast. All right, let's get on with the show. 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 episode, which is number 127, is an annual review, looking back at 2025. We're going to talk about research in ornithology this past. year that helped us deepen our understanding of birds. If you've listened to the podcast for a while, you know that I've done these annual review episodes every year, except, that is, for last year, 2024. And that's because in 2024, strangely enough, there were zero discoveries about birds.

Absolutely nothing interesting happened in 2024, so I wouldn't have had anything to talk about anyway. Just kidding. There are always, always new and fascinating discoveries about birds and interesting stories from the world of birding every single year. What really happened in 2024 was I was traveling in Asia at the end of the year, and I just wasn't able to make an annual review episode happen. So I'm excited to get back to it, to make an annual review episode for 2025. The plan is to first talk about a few studies in a bit of detail. tale. Then we'll do the speed round where I cover a bunch of studies or stories at rapid fire pace, describing each of them in 100 words or less, or more or less. After that, we'll talk about some

of this year's updates to avian taxonomy, species splits and all that fun stuff, and at the end I'll talk a little bit about myself and where the Science of Birds podcast is at the end of 2025. Now, I want to point out that this is not a comprehensive review of every scientific study on birds for the year. Rather, I'm just going to highlight published studies or news about birds that I think were interesting and or significant. I hope you think they're interesting too, of course. Shall we begin? Yes, indeed. This is the Science of Birds Annual Review 2025. Our first story is about Avalist, spelled A-V-I-L-I-S-T. To me, this is one of the most exciting things that happened in the world of birds this year.

Avalist is a single bird checklist of all the world's species. Now, that fact alone isn't special. For decades, there have been several global bird checklists. And those checklists are, one, the IOC World Bird List, IOC is International Ornithological Congress, two, the Clemens checklist, which is the one used by Ebert and Merlin and all that, three, the Bird Life International List, and then four, the Howard and Moore checklist. The existence of multiple global bird lists has been a problem. Ornithologists in different parts of the world, relying on different checklists, have never

completely agreed on the taxonomy of birds. So there have been all these discrepancies among the lists, different numbers of species and subspecies, different scientific names, and so on. The disagreement among the various checklists has created complications for bird conservation, scientific research, and even for the enforcement of international environmental laws. Not to mention the confusion this is caused for birders. For example, the IOC and Clemens checklists treated the North American populations of green-winged teal and the Eurasian populations as two separate species, the green-wing teal in North America and the common or Eurasian teal elsewhere.

A teal is a type of duck in case you're wondering. Anyway, the BirdLife International list traditionally lumped all these teal populations into a single species. So which is it? One species or two? Well, it used to depend on which bird checklist you trust to be the most scientifically accurate and reliable. As another example, there's the swamp hen split. This has been a major discrepancy over the years. The IOC and Clements lists split the quote-unquote purple swamp hen into six different species, including the Australasian swamp hen, African swamp hen, and gray-headed swamp hen. Meanwhile, the Bird Life International List kept all populations of these birds together,

lumping them into one incredibly widespread species, the purple swamp hen. At the taxonomic level of bird species, there were over 1,000 conflicts like this among the major bird checklists. Well, in 2025, this problem has finally been solved with the creation of Avalist. A bunch of expert ornithologists got together and they resolved those conflicts. They have created a single harmonized list, one list to rule them all. For the case of the green-winged teal, these ducks will be treated on Avalist as just one species, with a range that spans pretty much the entire northern hemisphere. As for the swamp hens, those six species will also be lumped into one species on Avalist. But the folks at Avalist note that more research is needed

on this species. Maybe it'll get split again in the future. But the point is, if such a split happens, it will exist on just one bird checklist, avalist. The same goes for any splits, lumps, or other updates. There won't be any discrepancies because there will be just this one standardized global checklist. Creating this list was, I imagine, an enormous amount of work, and it's an uplifting example of cooperation among scientists around the world. And it's just great that we'll have a single list going forward without all of the taxonomic confusion. Updating databases like those in eBird is complicated, and it's going to take some time before all the changes are made. So at the moment, there is still a small amount of discrepancy between the EBird slash clemenced list and Avalist.

But the Avalist Committee is working on reaching full alignment within the next year. Now I've been pronouncing it Avalist, since that's what I've heard the experts who created it say. So I'll defer to them, Avalist. But for the record, I think it should be pronounced Avalist with a long A. The AVI, Ava part, refers to birds, of course, because the Latin word for birds is Avis, or singular Avis. To me, saying Avalist instead of Avalist is like pronouncing my own name as Ivan instead of the correct way, Ivan. But, oh well, no big deal.

But if you ever hear me accidentally pronounce it Avalist, you'll know why. Next up, we have a study in the realm of of paleontology. The paper was published in the journal Science, and the title is Arctic bird nesting traces back to the Cretaceous. A PhD student, Lauren Wilson, and her colleagues discovered a bunch of rare bird fossils way up on the north slope of Alaska, at about 69 degrees north latitude. The dig site is called the Prince Creek Formation, and the fossils there are from about 73 million years ago. At that time, the site was was at an even higher latitude, about 80 degrees north.

The fossils analyzed in this study were the teeny tiny bones of hatchling birds. The collection included over 50 bones and bone fragments. Fossils of baby birds like this from the Cretaceous period are incredibly rare. Finding them, sorting them out, and classifying such fossils involves incredibly meticulous work. The most exciting thing about this discovery is that it shows us that birds were breeding in Arctic way earlier than we previously thought. Until this 2025 study, the oldest fossils from birds breeding in the polar regions was from penguins in Antarctica, dating to about 47 million years ago. So now we have evidence of several kinds of bird species breeding 30 million years

earlier than that, and we're talking birds making their nests right alongside some big old regular dinosaurs, non-avian dinosaurs. Because, unlike those penguins in Antarctica, these Alaskan birds lived before the mass extinction that happened 66 million years ago. The Prince Creek fossils in Alaska are from some diving birds that are sort of like loons and some gull-like birds and some that are like ducks or geese. Even though the planet was warmer overall 73 million years ago, at 80 degrees latitude, the location of the Prince Creek formation experienced about four months of total winter darkness and a summer with six months of continuous midnight sun.

So, and this is another exciting thing about this study, those breeding birds were almost certainly migratory. When the cold and darkness of winter descended, those birds got the heck out of there and they headed south. This study reveals that the behavior of long-distance seasonal migration in birds is tens of millions of years older than we thought. And I find it fascinating to think about what the environment was like where these Arctic birds were nesting.

My understanding is that it wasn't the treeless frozen wasteland we see today. The main annual temperature was roughly 41 to 45 degrees Fahrenheit or 5 to 7 degrees Celsius. Summers would have been pleasant and productive, with temperatures reaching 64 to 68 degrees Fahrenheit or 18 to 20 degrees Celsius. But winters were still dark and chilly, with temperatures dipping below freezing. The ecosystem of the Prince Creek formation was a polar forest. It was a lush, low-lying coastal plain with meandering rivers, swamps, and lakes. The forest canopy was dominated by deciduous conifers that dropped their needles in winter to survive all that darkness,

and the understory was filled by ferns, mosses, and broad-leaved flowering shrubs. Among the large non-avian dinosaurs stomping around was the feathered, polar-adapted predator, Nanooksaurus. That genus name translates as the polar bear lizard. It was a cousin to Tyrannosaurus, with a length between 20 and 30 feet long, or 6 to 9 meters. Most artistic recreations of Nanooksaurus show it covered in shaggy white feathers. And that would be super cool. It's possible, but I don't think there's any direct evidence for it. One more significant thing about this 2025 study, it's possible that some of the Prince Creek fossils are from a lineage called neornathies, or what ornithologists call the lineage of modern birds. Every bird species alive today is in the Neornathies lineage. If it turns out that the Prince Creek fossils really do belong to neornathies, then they are the oldest modern bird fossils ever found, ever.

And that would be a major discovery. So I guess we'll stay tuned for the answer on that. Our next study is titled Environmental Variability Shapes Life History of the World's Birds. It was published in the journal Ecology Letters, and the lead researcher is Casey Youngflesh. and this research was conducted in the lab of Phoebe Zarnetsky at Michigan State University. I just wanted to give her a shout out because she's a friend of mine from when we were both getting our PhDs here in Oregon.

Anyway, in birds and other animals, biologists sometimes talk about their pace of life, not as in how busy their daily schedules are, with a fast-paced life of driving their fledglings to soccer practice, putting in long hours at the office, partying all weekend and taking big financial risks on the stock market, the stork market. No, what biologists mean by pace of life is how long a bird lives, as well as when it becomes sexually mature, how often it reproduces, that sort of thing. And more broadly, these biological traits fall under the banner of what biologists call life history traits. Some birds have a slow pace of life. They mature slowly, have a long generation length, and have a relatively high rate of survival.

An example is the sulfur-crested cockatoo of Australia and New Guinea. That species is on the extreme end of the slow pace of life spectrum, with a generation length of about 27 years. Generation length is the average age of parents when their offspring are born. For comparison, generation length in humans is also about 27 years. At the other extreme, we have birds like the double-barred finch, an adorable little bird that's also from Australia. It has a really short generation length at just 1.4 years.

For a long time, biologists have wondered why some animals have a slow pace of life, while others have a fast pace of life. Well, this 2025 study goes a long way to helping us understand what's going on, at least for birds. The researchers used a massive data set of 7,477 birds species, all of which are non-migratory land-dwelling birds. To measure how fast or slow a bird lives, the team used generation length as their primary metric. And then there was the climate data. This was also a large data set, 73 years of global climate records, from 1950 to 2022. It was used to calculate how much temperature and precipitation varied both within years

and across years for every location on Earth. Some sophisticated statistical models combined the bird and environmental data to see how environmental variation is related to generation length. The researchers made sure to account for, to control for other things that can affect the pace of life, such as body size, what a bird species eats, and their evolutionary relationships. So what did this study reveal? The researchers found that high inter-annual temperature variability, so big changes from year to year, leads to a slower pace of life. Having a slow pace of life is probably a sort of bethaging strategy, where the species spreads its reproductive efforts out, over its long life. That way, it's more likely to make lots of babies successfully over

its lifetime, even though there are bad years here and there. So a slow pace of life appears to have evolved more often in birds that live in environments where temperature varies a lot from year to year. Tropical and subtropical places tend to be in the category of high inter-annual variation. Places like South America and Central Africa, In contrast, this study found that high intra-annual variability in temperature, in other words, strong seasonal changes that happen within a single year, that actually leads to a faster pace of life. This is often because harsh winters or dry seasons create bottlenecks that reduce adult survival.

A lot of birds die during those challenging bottleneck seasons, and that creates an evolutionary pressure forcing birds to reproduce quickly while they can. Live fast and die young and all that. North America is an example of a region where the seasons are strikingly different. It can be hot and humid in the summer and bitterly cold and icy in winter. So there's high intra-annual variation in temperature and precipitation. The 2025 paper points to Madagascar as another place with high intra-annual temperature fluctuations.

An example of a bird that was given for Madagascar as the Madagascar Scops owl. It has an extremely short generation length for an owl at only two years. So that fits the pattern of birds living in places with high intra-annual temperature variation tending to have short generation times. I should point out that it was temperature that has the strongest association with pace of life, not so much with precipitation. And finally, the researchers took their day. data further and they were able to calculate how fast the environment today is changing relative

to each bird's lifespan. This is a new way to assess which bird species are more at risk, because species with long generations might not be able to evolve, to adapt, fast enough to keep up with the rapid pace of environmental change caused by global warming. Our next study has to do with an eclipse, where the moon passes in front of the sun, creating a vast shadow that turns day into night for a few minutes. Specifically, we're talking about the great North American eclipse that happened on April 8, 2024. The moon's shadow passed over North America and the path of totality swept through the eastern part of the continent. The eclipse itself happened in 2024, but the paper was published in 2025 in the journal's scientific reports.

The paper's title is Continental Scale Behavioral Response of Birds to a Total Solar Eclipse. The lead author is David Mann. Imagine that it was a sunny spring day on April 8th, 2024. The birds across the U.S., Canada, and Mexico were singing their little hearts out. They had no idea an eclipse was coming, and then all goes dark over a relatively short time. How do you suppose the birds responded? Well, what this study found was that birds generally decreased their singing and calling when it got dark. They behaved more like they do at night.

Or since birds presumably don't understand how eclipses work, maybe they got all quiet because they thought the end of the world was nigh at hand. they were stricken silent by existential dread, or they were just stoically contemplating the destruction of all life on Earth and making peace with all of that. But really, who knows what they were thinking? In any case, at locations where more than 99% of the sun was covered by the moon, there was at first an increase in bird vocalizations 10 to 30 minutes prior to the peak.

That's interesting. Maybe this increase was like what many birds do in the evening, or they get more vocal for a while before bedtime. Then what this study found was that birds significantly decreased their singing and calling during and immediately after the eclipse's maximum, the peak. This moment of silence began at the moment of totality at the peak and lasted for about 12 minutes. So there was this lag or residual response to the sudden changes in light and temperature that happened at the moment of totality.

Now, it's important to note that this was just a general pattern. There was, in fact, a lot of variation among bird species in how they responded. And there was variation among different locations. For example, American Robbins just kept singing pretty much continuously through totality. They didn't seem to be phased by the eclipse. One explanation is that during the breeding season, the American robin is a species that participates in what's called the dusk chorus, where birds get more vocal around sunset, and some, like the robins, will sing for hours into the

evening. With your razor-sharp intellect, I assume you are, at this point, wondering how the researchers in this study got their data. How does one collect data on bird vocalizations over just a couple hours, all at once across an entire continent. Well, it turns out that David Mann, the lead author on this project, is one of the creators of a little device called Haiku Box. This box is an automated acoustic sensor. It listens to bird sounds in the immediate area, filters out any human noises,

and is able to identify birds from their songs and calls in real time. Hikou Box uses super fancy machine learning algorithms to ID. Byrds. It's similar to what you can do with the Merlin app, but with Haiku Box, you just set it up and leave it on forever. It works 24-7 to ID Birds. You might remember that Haiku Box has been a sponsor of the Science of Birds podcast in the past. It's a product that you can buy. And I have one of these devices on my balcony right now. It's out there listening to and identifying whatever birds are making noise on my block. Hikou Box is just super cool. But for record, haiku box is not sponsoring this. I just really dig these devices, and I think this study was

interesting. Anyway, the researchers were able to collect data from 344 haiku boxes across North America. Initially, there were over 600 devices that potentially could have been included, but some had to be weeded out for data quality reasons. I think this study is cool because, one, we learned some interesting things about bird behavior, and two, it does. demonstrates the power of passive acoustic sensors and citizen science. The owners of each haiku box opted in to allow their data to be used for the greater good, to be used by scientists to help us better understand birds. All righty.

So we've talked about avalist, prehistoric birds nesting in the Arctic, the effect of environmental variability on pace of life in birds, and the way birds responded to an eclipse. Now it's time for everybody's favorite part of the annual review episode. It's time for the speed round. I'll tell you about some more studies and stories from 2025, but we'll move through each of them at a breakneck pace. I'm limiting myself to about 100 words to describe each of the following studies or stories. I'll provide references for all of them in the show notes on the Science of Birds website, and that goes for the four studies we already covered. Hold on tight and prepare yourself for a tidal wave

of ornithological discoveries. Did you know Birds of Paradise literally glow? Research reveals that nearly all species in the family, Paradisiidae, use biofluorescence during courtship. They absorb high-energy light and re-emit that light as vivid green and yellow glows from their mouths, skin, and feathers. Why? Because it creates a high-contrast color pop against their famous super-black plumage. Fluorescent colors make a male's dance moves even more appealing to females. Since these birds have vision specifically tuned to these fluorescent colors, this dazzling color display is a critical adaptation for sexual communication in the dark corners of the tropical rainforest.

The bearded vulture is more than just a scavenger. It's a sort of museum curator for humans, it turns out. Scientists studying ancient vulture nests in Spain found that these birds reused the same cliffside sites for hundreds of years, creating a natural museum. These layers of history contain everything from animal bones and eggshells to human artifacts, like fabric, a sandal from 700 years ago, and even a friggin' crossbow bolt.

Sick! By picking up such random items to build their nests, vultures have preserved a record of our shared history. Conservationists are now using these vulture archives to monitor environmental changes and protect these magnificent birds. How do you study the brain of a bird that's been extinct for millions of years?

Traditionally, there was a lot of guesswork, but a new study of 136 species from across the avian tree of life has confirmed a breakthrough. The surface area of a skull's interior, called an endocast, is an excellent proxy for actual brain volume. This means scientists can use non-destructive CT scans of fossils to map the cognitive and physical abilities of extinct birds with a lot of precision. Among other things, this discovery provides a way of tracing the evolutionary path from dinosaurs to modern birds. We've known bird populations are declining, but a new study using e-bird data reveals a shocking twist. Some of the biggest losses are happening in the places where birds are usually the most abundant. By mapping 495 species across North America, researchers found that the strongholds, the core habitat,

for these birds, are actually the most imperiled. This trend is especially severe in grasslands and arid regions, where environmental stressors are changing faster than birds can adapt. So this study gives us a map to pinpoint exactly where help is needed most before these traditional avian strongholds disappear. After 40 years of being extinct in the wild, the Guam Kingfisher, or Seahek, S-I-H-E-K, is finally back in the trees. In a big collaborative effort involving international zoos and government agencies,

six captive-bred birds were recently released onto the predator-free Palmyra Atoll. These wonderful birds were wiped out on their native island of Guam by invasive snakes. But this successful relocation marks a massive win for their conservation. While Palmyra Atoll is a temporary sanctuary, this release serves as a critical proof of concept and a beacon of hope. It's the first major step in the journey toward eventually bringing the Seahek back home to Guam. A discovery in China provided an update to avian evolutionary history. Paleontologists have unearthed Bamanormus jengensis, the oldest short-tailed bird ever found. Dating back to the late Jurassic, this species possessed a modern skeletal structure roughly 20 million years earlier than previously recorded.

This discovery bridges a massive gap in the fossil record, and it suggests that birds evolved and diversified quickly after splitting off from the other dinosaurs. It shows that the diversification of birds was already well underway a lot earlier than we thought. For years, we thought songbirds were lone wolves during their long. long-distance nighttime migrations. But it turns out they're actually quite social. Using deep learning algorithms to analyze 18,000 hours of flight calls, researchers discover that different species form intentional travel groups in the dark. These aren't random pairings. Birds choose companions with similar wing shapes and flight speeds so they can stay

together. And again, these aren't flocks of a single species. They're groups of different species, and that's just really cool. By sharing information through their calls, they help each other navigate and survive the long flights through the dark. It turns out Flamingos aren't just passive filter feeders. Research in 2025 shows these birds are actually manipulating the water around them at a small scale. By combining 3D simulations with robotics, scientists discovered that flamingos use their L-shaped beaks and webbed feet to create tiny underwater tornadoes or vortices. These little currents stir up and trap prey like brine shrimp, pulling them into the bird's mouth. So the unique anatomy of flamingos gives them hydrodynamic adaptations so they can

gather food more effectively. These anatomical features are so efficient they might provide a blueprint for new human-made water filtration systems. A massive collaboration led by UC Merced, the University of California, Mersed, and the Cornell Lab of Ornithology, has produced the first truly comprehensive tree of life for pretty much all-known bird species. By synthesizing data from nearly 300 different studies, researchers created a single unified framework that will help resolve centuries of debate about, about how different bird families and species are related. And this digital avian tree of life is designed to update automatically as new DNA data comes in.

It's a living document and a database of avian history that can provide a great foundation for future bird research. So we have this new avian tree of life being published the same year as Avalist comes online. Those two things will hopefully work together to really help us in study. bird diversity and evolution. Why do birds that are only distantly related often act the same way? To find out, researchers looked at five different bird families, those of swallows, sparrows, warblers, thrushes, and wrens, each of which has species that nest in tree cavities.

Because nesting holes are rare, these species have all evolved high levels of territorial aggression, especially the females. While they share the same belligerent behavior today, the brains of species from different families actually took different genetic paths to get to that behavior. Only a tiny core set of genes is used across all species to trigger this aggression. This study shows that while evolution often repeats the same behaviors to solve a problem, it often finds a unique genetic path to arrive at that behavior for each independent lineage.

If you live in a North American city, the Cooper's Hawks in your neighborhood might be smarter than you think. A new study reveals these raptors have learned to read city traffic to hunt more effectively. Researchers observed hawks using lines of cars at red lights as physical cover to sneak up on prey. Even more impressive, they seem to understand acoustic pedestrian signals, using the chirps of crosswalks to time their attacks when traffic is most congested. This is the most advanced example of a raptor adapting to urban life ever recorded, showing incredible cognitive flexibility in our backyard predators. What's next, Cooper's Hawks? Google Maps?

And with that I say to you, dear listener, congratulations! You survived the speed round. I know that's a lot to throw at you all at once. but I feel like I needed to include all of these stories. I didn't want to leave anything out. Let's move on now to talk about taxonomy. Remember at the beginning of the episode, we talked about the global bird checklists

and how going forward there's going to be just this one unified checklist, avalist. Well, ornithologists regularly review the taxonomy of birds, the way birds have been classified into orders, families, genera, species, and subspecies. New discoveries and analyses often lead ornithologists to revise the taxonomy of birds, usually once a year. So what happened in 2025? We certainly can't go through all of the changes to bird taxonomy, but let's talk about a few notable examples. At the highest taxonomic level, the level of order, we actually lost one in 2025.

It used to be that the Jackamas and Puffbirds, the families of those birds, were what formed the order Galbulaformis. Well, that order is no more. I guess this group of birds isn't genetically distinct enough to warrant having its own order. Jackamars and Puffbirds are now included in the expanded order piciformis. Piciformis includes woodpeckers, toucans, barbits, and all those guys. And now it includes Jack Mar's and Puffbirds, too. We also lost a few families, as these were subsumed into other families. For example, the ground hornbills in Africa used to have their own family, Bucorvody. But that no longer exists. Those birds were moved into the normal hornbill family, Bucerodody. One avian family had a name change. The family formerly known as Skodosurcidi,

the bush-warblers and allies, has been renamed Setedi, with a sea. Birds in that family are found in Europe, Africa, and Asia. We had some shake-ups here in North America. For example, the pied woodpeckers of North America have been moved into different genera to reflect that they are not closely related. The downy woodpecker remains in the genus Dryobaties,

but its larger look-alike, the hairy woodpecker, is now in the genus Lucanotopicus. Some other species like the white-headed, Arizona, and red cockated were also moved to that latter genus. The common names of these birds haven't changed, just their underlying taxonomy at the genus level. Continuing with North America, the warbling virio was split into two species, the eastern warbling virio and western warbling virio. The geography of their split is roughly around the rocky mountains. While these two species look very similar, their song,

are significantly different. The yellow warbler was split into the northern yellow warbler and the mangrove yellow warbler. The northern yellow warbler is the species that would be familiar to most of us across North America. In shorebirds, we have the Wimberl, which was split into the Hudsonian Wimbril in the Americas, and the Eurasian Wimbril in the rest of the world. You might remember that my favorite place to go birding in the U.S. is Southeast Arizona. Well, the shining star bird of that region has been the elegant trogon.

But that species is now split into two species. The one found in Arizona, which is the only, pretty much the only trogon in North America, that now is called the copper-tailed trogon. One notable change in Europe, the red grouse in the British Isles is now considered to be a full-blown species, rather than just a sub-species of the Willow Tarmigan. So this means the red grouse is now considered an endemic species in Britain and Ireland, and that's pretty cool.

Coincidentally, I'll be heading to England in the spring, so you know what I'll be looking for. Red grouse, baby! The striated heron, a species that had a global distribution, got busted up in a three-way split in 2025. The striated heron in the strict sense is now defined as the species widespread in South America. Then over in the Galapagos Islands, there's the lava heron, which is endemic to the archipelago. Finally, the third species from that split of striated heron is the little heron, and that one lives in Africa and the Middle East through Asia to Australasia.

Now again, there's a lot more that changed in bird taxonomy, but those are just some of the highlights. Overall, the number of bird species in the world grew by a net gain of 22 species. We gained 40 species from splits, and we lost 18 from multiple species being lumped together into a single species. So, 40 gains minus 18 losses, that's how we get a net gain of 22 species. All right. Last and probably least, I want to just give you a little report on the status of myself and the science of birds podcast as we leave 2025 far behind us. I published 26 episodes in 2025,

including the new Random Bird Thursday episodes. Random Bird Thursdays were new for 2025, and I've really enjoyed making them, and it seems like many of you listeners enjoy them too. So expect a lot more of those. Overall, the podcast got about 722,000 downloads in 2025. That's across all the episodes. And that's just amazing, and I'm just thrilled that my show is reaching so many people. I was just looking back and reading my journal from the first few months of the podcast back in 2020. Back then, I was dreaming of maybe getting 1,000 downloads for a new episode in its first 30 days after being published. Now I get that many downloads within the first 30 minutes after I publish. Crazy! Another new thing for 2025,

was that I launched bird merch, my online store with a bunch of bird-related t-shirts over at birdmerch.com. And that's been going pretty well. Thank you so much to everyone who has purchased shirts, and I'm excited about growing bird merch even more in the coming year. I have a long list of shirt designs that I'm really excited to make. If you've been following the podcast and maybe my Science of Birds Instagram account, you know I did a lot of traveling in 2025. I started the year in Bhutan for a few days, then I eventually went to Patagonia, Central Chile,

China, Mongolia, and Japan. And most of that was for work for my birding tour company Wild Latitudes. And of course I had countless amazing experiences with birds in those places. Looking back at my e-bird data, I recorded 719 bird species in 2025. That's a little bit less than in previous years,

but hey, no complaints. because it was another fabulous year, living a life that is almost entirely devoted to birds, to seeing and appreciating them, to learning about them, and to teaching others about them. I'm super excited about all the good things to come in 2026, and I hope you are too. Thank you so much for listening. If you're listening to this episode when it first drops, then to you, I say, Happy New Year! I hope you have an amazing 2020. But if you're listening at some later date, like in the year 2052 or something, well, I hope you're having a glorious day.

Just don't forget to report to your robot overlords or there might be unpleasant consequences. Thank you so much to all my supporters on Patreon. I could not have kept the podcast going without you this year. And a big welcome to the newest members of my Patreon community. Mary Manoli, Jim Prawl, Sherry Whitfield, Katja Radkavik, James Kane, Spencer Worthing, Carol Chen, Marty Burroughs, Sarah Rose Saluce, Nancy Stassinopoulos, Archer Powell, Holly Chris Caruso, and Ukawashearay. Sorry if I mispronounced anybody's name.

In any case, thank you all so much. You totally rock. If you, my friend, have some interest in supporting this podcast as well, you can check out my Patreon page at patreon.com slash science of birds. There's also a little support-the-show link in your podcast player app in the show notes. You can shoot me an email if you have something you'd like to share with me, like some new discoveries in your own life over the last year, or an amusing anecdote. In any case, my email address is Ivan at Science of Birds.com.

This again is episode 127. You can check out the show notes for the episode on the Science of Birds website, scienceofbirds.com. I am Ivan Philipson, and I wish you a most excellent day. Peace.