The Science of Birds - Ask Me Anything About Birds - Nov 2021

Episode Date: November 16, 2021

This is a special episode, and the first of its kind. I answer questions from my listeners. It’s a fun, mixed bag of bird factoids.Who were these lucky people who got to contribute to this episode? The specific listeners who submitted questions were my supporters on Patreon.Of course, the idea is that our discussion today will be interesting and informative to all of my listeners.This Q&A session covers things like bacterial diseases, bike helmets, lemon-scented juncos, and baby owls!~~ Leave me a review using Podchaser ~~Links of InterestWoodpeckers and Brain Injury Prevention Bird song could hold clues for human disordersReferencesThe role of ecologic diversification in sibling speciation of Empidonax flycatchers (Tyrannidae): multigene evidence from mtDNA [PDF]The Evolution of Stomach Acidity and Its Relevance to the Human MicrobiomeA Systematic Review of Carrion Eaters' Adaptations to Avoid SicknessFeatures of owl wings that promote silent flightUpwash exploitation and downwash avoidance by flap phasing in ibis formation flightLink to this episode on the Science of Birds websiteSupport 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, guided exploration of bird biology for lifelong learners. This is a special episode. the first of its kind. Today, I'm going to be answering questions from my listeners. I've never done this before. It's going to be a fun, mixed bag of bird factoids. Who were these lucky people who got to contribute to this episode? The specific listeners who submitted questions were my

supporters on Patreon. I currently have a couple tiers or membership levels on my Patreon page. Each level comes with certain perks. One perk for the helpful horned. hornbill membership level is getting to ask questions for episodes like this. So thanks very much to my helpful hornbills for submitting your excellent questions. High fives to you guys. I'm excited to provide you with the answers you desperately crave. Your insatiable thirst for knowledge is an inspiration to us all. Of course, the idea is that our discussion today will be interesting and informative to all of my listeners.

All y'all. All ready. Let's get down to business. The first question today has to do with disease in birds. Donna Accord asks, Is there any new information on the virus that took out so many birds at bird feeders last year, especially pine siskins. In the winter of 2021, people in North America started finding dead and dying songbirds in their yards. This happens every year, to some extent, but it soon became clear that something

unusual and disastrous was unfolding. I saw this firsthand. My wife and I found a couple of pine siskins that had died in our yard. This is a small songbird in the Finch family. We were really sad and concerned. We weren't sure what had happened. It turned out that sick pine siskins were being reported all across the country, not just here in Oregon. Wildlife care centers were being inundated with sick siskins and other birds, and it was rare for any of these sick birds to survive. The culprit was actually bacteria, not a virus. The deadly illness was caused by bacterial species in the genus Salmonella. You've heard of it before. In humans, Salmonella, and humans, salmonella. can cause an infection when we eat food contaminated with bacteria.

The condition is called salminalosis. It causes diarrhea, fever, and vomiting. Birds too can get salmonellosis. The bacteria spread through their feces. If a bird eats or drinks from a source tainted with bird droppings, it can get sick. Once people figured out what was happening, wildlife agencies across the country asked people to take down their bird feeders and their bird baths. These can be hot spots of salmonella transmission.

My wife and I took our feeders down for the winter once we heard the news. It was a bummer not to have our little buddies around for a few months, but it would have been way worse to have a hand in the deaths of any more birds. So why was there a major outbreak of salmonellosis in the winter of 2021? If bird feeders are the problem, wouldn't this happen every year? Well, this whole thing was related to a rare natural event. event. In late 2020 and early 2021, there was a huge eruption. No, not an

eruption. No volcanoes were involved. That would be cool, but no, we're talking about an eruption, I-R-R-U-P-T-I-O-N. This is what biologists call the cyclical mass movements of birds that sweep southward from northern latitudes in the winter. It doesn't happen every year, so eruptions are not the same as the annual migrations of birds that fly south. What causes an eruption is usually a lack of food in the north. During winters when conifer seeds are in short supply in the boreal forests of North America,

the U.S. sometimes gets invaded by hordes of birds like hoary red poles, evening gross beaks, red crossbills, and, you guessed it, pine siskins. In other non-irruption years, these birds are typically more rare. There were so many erupting birds last winter of so many species that ornithologists called the event a superflight. It was pretty awesome for us bird lovers. So you've got this superflight going on, and then those birds swoop into our backyards by the dozens or hundreds to gorge themselves at our feeders. They're stuffing their little crops with seeds. They're sitting around, gossiping, and they're drinking from the bird bath.

And they're pooping. More birds equals more poop. More poop means more opportunities for salmonella bacteria to spread. Sadly, birds can't read or speak English. Otherwise, they would have gotten the message last winter about the need for social distancing and using hand sanitizer. Well, I guess they'd have to use beak sanitizer. So that's what happened.

It was the biggest salmonella outbreak in birds that anyone had seen for decades. I'm not sure why pine siskins seem to be more affected than other species, probably because they're gregarious and move around in flocks in winter. There would be more opportunities for bacteria to spread among them. And perhaps they have some special vulnerability to salmonella. I don't know. I just hope this doesn't happen again. I'm totally looking forward to the next bird eruption, but if I see siskins gathering at my

feeders this winter, I'll probably take them down. The feeders, that is, not the birds. This all points to our responsibility to keep our feeders and bird baths clean in every season. We should clean them regularly with soap and water. Or you can use a diluted bleach solution. The Audubon Society recommends a solution of nine parts water to one part bleach. Just rinse everything off super thoroughly and dry it off before putting it back up. Let's carry on with the theme of bacterial diseases, because why not?

The last episode of the Science of Birds was about the family cathartity, the New World vultures. I suspect that at least one of my patrons enjoyed that episode, because Maggie Billings says she loves turkey vultures, and those guys are in the family cathartity. Maggie's question was this. What is it about turkey vultures that makes them able to eat carrion and immune to so many diseases? What other birds eat carrion and what makes them able to do that? Maggie posted her questions before I published the New World Vulture episode. So I think I've at least partially covered this already. But the basic idea is that New World vultures have super acidic stomachs.

That acid disintegrates most of the harmful bacteria. that grows in rotting meat. So that's one way that these birds avoid disease. The hydrochloric acid in human stomachs provides a similar protection against microorganisms. The pH of a typical adult human stomach is something between pH 2 and 3. Vultures, on the other hand, have pHs around 1.2 or 1.3. Now, I'm saying stomach in reference to these birds, but technically it's the proventriculus. The proventriculus is the part of the avian digestive system that involves chemical digestion of food. Anyway, it's not just new world vultures that have sizzling acid baths sloshing around in their tummies. Other obligate scavengers like old world vultures also have

this adaptation. Remember, obligate scavengers feed on nothing but dead animals. Facultative scavengers eat carrion sometimes but also eat live stuff. Well, some facultative scavengers like bald eagles and the common buzzard appear to have super low pH in their stomachs too. Now when you hear the word buzzard, maybe you're picturing a vulture, but the common buzzard, beautyo-buteo is actually a hawk. It's a close relative of the familiar red-tailed hawk. Having strong stomach acid is also common among carnivorous birds and other animals, so this isn't unique to carrion eaters. I found an interesting research paper titled

A Systematic Review of Carion Eaters' Adaptations to Avoid Sickness. How's that for Appropriate? It was published in the Journal of Wildlife Diseases in 2017. I'll put a link to it in the show notes. This paper considered several hypotheses that might explain how corpse-munching critters avoid getting sick. Long story short, only a few of the hypotheses have any real scientific support. Strong stomach acid, or low gastric pH, is one of them. Having certain helpful

microorganisms living in your guts may also be beneficial. That's another hypothesis with some support. This has to do with what we call the gut microbiome. This is the community of microbes that hang out and thrive in the intestines. In the last episode, I talked about how turkey and black vultures have claustridia and fusobacteria in their intestines. These bacteria may defend against other harmful species, or they may simply out-compete them. It's uncertain. The adaptation to carrion eating that seems to have the most support, however, is having a strong immune system. Vultures, at least some old-world species that have been studied, appear to have specialized immune receptor proteins that recognize pathogens.

These birds may also have an enhanced ability to develop antibodies to pathogens and toxins from a young age. Hopefully, future research will shed more light on this topic. I wonder if scientists will discover some of these same adaptations in other birds that partake of the occasional roadkill or whatever. I'm thinking of ravens, caracaras, carrion crows, and sheathbills. Sheathbills are weird white birds that live in Antarctica and elsewhere around the southern ocean. They're garbage guts that eat just about any meat they can grab, including carcasses. Our next question comes from Haley.

This one has to do with what defines bird species. Paraphrasing Haley, she asks, Why do some birds that are technically different species look so freaking similar that some bird guides suggest not even trying to identify them, while other birds of the same species can have so many variations? Ah, yes, the challenge of identifying bird species that look nearly identical to the human eye. The classic example that frustrates birders in North America is flycatchers in the genus Mpidon. This is a group of about 15 species in the family Tyrannity. They're small, drab birds with pale

wing bars. Species like the Pacific Slope Flycatcher, Cordillian flycatcher, and Dusky Flycatcher can be nearly impossible for many birders to tell apart in the field, if they're just going by appearance. Heck, the Pacific Slope flycatcher even has the scientific name Impidinax Diffacilis. A fitting name, Diffacilis. Because by, by being identical to its cousins, the Pacific Slope flycatcher takes pleasure in making your life difficult. What's going on with these impetanax flycatchers? Why don't they just be all colorful and unique so we can tell them apart from a mile away? Haley's question and the question of what's the deal with impinac's flycatchers both scratch at the surface of much larger topics.

Specifically the topics of how we define species and how one species can evolve into multiple species. I already tried to clarify some of this in episode 15 of the podcast, which is titled What is a Species, really? Empedanax flycatchers are what we call sibling species. They're closely related species that also look very similar, if not identical, at least to us. But sibling species don't interbreed.

If they could freely interbreed and did so in the wild, then they wouldn't be separate species, right? We'd probably lump them all into one species. I say probably because bird classification can be messy and often hotly debated. Ornithologists can't always agree on which birds are distinct enough to be treated as species. That's at least a piece of the answer here. Birds, of course, don't care about any of that. What matters to a bird is, who can I mate with, who are my rivals, and who can I safely ignore? Birds recognize who is or isn't a member of their own species in different ways. With visual cues like plumage color, yes, but also by using sound.

For example, each of the 15 impidanax flycatchers has a distinct song and distinct calls. So IDing them by ear can be much easier for us birders. Since each impid flycatcher species sings its own song, it's likely that sound matters a lot to these little buggers. Moreover, they occupy different habitats, and they nest in different places and often have geographic ranges that overlap very little, if at all. So these seemingly identical birds maintain their distinctiveness

because there are barriers that keep them from making babies together, reproductive barriers. At some point in the misty depths of time, there was a single common ancestor of the 15 mpid flycatchers. Probably hundreds of thousands of years to maybe a few million years ago. That's not that long in evolutionary terms. Why do some species look so similar? Well, having a recent common ancestor like this is one way this happens. Given more evolutionary time, however, we might see our similar-looking flycatchers diverge in a

too, not just in their vocalizations. The bottom line is, I think, bird lineages can split off from a single ancestor and become reproductively isolated without looking different. They can become new species and still not look different. What matters is whether they interbreed and to what extent. There can be these other barriers that keep them separated, like songs, habitats, and geography. The second part of Haley's question was about the situation where a single species has multiple distinct looking forms. She brought up the dark-eyed junco as an example. The dark-eyed junco, Junco Hyamelis, is an adorable, uber-familiar backyard bird in North America.

It's in the New World Sparrow family. There are several subspecies of dark-eyed junco, and each one looks different. The subspecies have names like slate-colored. white-winged, pink-sided, dim-witted, and lemon-scented. A couple of those aren't real. I'll leave it to you to figure out which. Until the 1970s, ornithologists actually considered some of these subspecies to be fully distinct species. Taxonomy changes like that as we gather more data.

Genetic data from the genomes of birds is the gold standard these days. There's a chance that some of the junco subspecies will, some point get restored to their former glory as species. Or with genetic data, maybe whole new species will be defined. The array of bird lineages we currently lump under the name Dark-Eyed Junko has diversified only very recently, probably in the last 18,000 years or so. It's amazing that so many differences have already evolved in these birds. There are physical outward differences, and there are also significant genetic differences. What we're looking at is the process of species formation in action. In the case of juncos, it's complex. It's messy, and

scientists haven't figured out exactly what's going on yet. Even with lots of genetic data available for the dark-eyed junco, this bird continues to be a taxonomic challenge. I guess one take home here is that it can be hard for biologists to decide what is or isn't a species, both in the general sense and in individual cases like the dark-eyed junco. Another take home is that the process of species formation, in other words, speciation, is gradual and sometimes tangled. The boundaries between lineages can be blurry for thousands or maybe millions of years, which is a big reason why biocations. psychologists sometimes struggle to sort everything out.

Okay, folks, I can see a big hook coming at me from stage left, so that's my cue to wrap this one up. Let's move on to the next question. This question comes from Jason Corrielle. Here's a paraphrased version of what Jason wrote. I'm a neurologist, and I loved learning about adaptations that woodpeckers have to prevent traumatic brain injury. This makes me wonder, do we use bird science to advance human medicine? For example, how to design better helmets? In general, what advances in medicine, physics, and chemistry have been made through our knowledge of bird biology? This is a really interesting

question. I think Jason was referring to episode 11 of the podcast, which was about the Woodpecker family. I talked about how these little hammer-headed birds avoid getting concussions or brain damage. They have several adaptations for this purpose, including their shock-absorbing hyoid bone and their tongue, which helps maintain blood pressure in the head to provide cushioning. Woodpeckers have indeed inspired innovations in helmet design, including bicycle and football helmets. One cool design for the lining of a bike helmet is made of cardboard. The helmet's creator, Anaruda Surabi, reports that this cardboard liner absorbs three times the force of a typical polystyrene liner.

So Robbie's invention is based on the cushioning properties of spongy cartilage and bone in the woodpecker skull. Woodpecker anatomy has also been mimicked in the design of an ice axe and in shock absorbers. Other birds have been used as blueprints for technologies like airplane wings, trains, and aerial drones. These are all examples of biomimicry. This is where human engineers take inspiration from nature, using what they learn from animals and plants to solve human problems. Evolution has, through millions of years of trial and error, honed the anatomies and behaviors of birds for specific functions.

So why should humans reinvent the wheel? We can just copy the adaptations of birds. Now, how has research on birds benefited human medicine? I have to admit that I had a harder to time finding examples of this. One thing to keep in mind is that birds and mammals have been evolving on separate paths for over 300 million years. Even though we share a lot of our basic anatomy and physiology, birds and people are also extremely different on many levels, in case you hadn't noticed. So I'm guessing it's not all that common for scientists to make medical discoveries in birds that apply directly to humans. In other words, birds usually aren't the best models for human medicine. That said, however, research on zebra finches has led to important discoveries

of how language develops in humans. From a medical viewpoint, what we've learned from these birds is also helping us understand the sources of some speech and cognitive disorders in people. The zebra finch, tiniopygia gutata, is native to Australia and parts of the Indonesian archipelago. This charming little bird has become a model organism in biological research. It's in the ranks of animals like rats, mice, guinea pigs, and rhesus monkeys. It turns out that songbirds like the zebra finch learn their songs in a way that is similar to how human children learn languages. The brain structures of birds and humans are dramatically different, and yet the neurodevelopment of song and speech in the two groups, respectively, are analogous.

For example, songbirds and kids have only a certain window of time in their early development where they can really absorb the sounds made by their parents or whoever is around. After that period, it becomes very difficult or impossible to learn to sing or speak properly. The entire genome of the zebra finch has now been sequenced, so some of the most exciting discoveries are on the genetic front. For example, scientists have figured out that some of the same genes in zebra finches and humans play important roles in vocal learning. A couple of genes named Fox P1 and Fox P2 have been studied extensively. Mutations in these genes can cause serious problems in humans. There's even an autism-like condition called,

Foxp.1 syndrome. It's possible that what we learn about the brains and genes of zebrafinches will help doctors both understand and treat human developmental disorders like autism and speech disorders like stuttering. From a scientific standpoint, that's pretty cool. Of course, there are ethical questions around using lab birds and other animals in medical research like this. If you're an animal advocate like me, this might be something you have some issues with. this is a huge and controversial topic it's well beyond what we're talking about today so let's pull out another listener question the next couple of questions have to do with owls everybody loves owls right i'll be putting together some episodes on owls at some point so stay tuned for those

For now, let's look at the Great Horned Owl, Bubo Virginianus. This is a large, impressive bird. It's a familiar, iconic species in the Western Hemisphere. It lives across all of North America and in large parts of South America. The question here comes from Kate Haslett. She asks specifically about the breeding biology of the Great Horned Owl. Kate wanted to know about the very animal. stages of life for young owls. Well, here's the rundown. Greathorned owls form monogamous pairs.

A male and female will usually defend their territory all year long. In late winter or early spring, the female lays one to four eggs. The eggs hatch after a month or so of incubation. The world rejoices with the arrival of some helpless baby owls. Hooray! Hooray, right? That just happened. I didn't plan it. Seriously. Hooray! The baby owls grow rapidly, feeding on scraps of meat delivered to the nest by dad and doled out by mom. About six weeks later, the youngsters start venturing out of the nest onto nearby tree branches. The fledglings will hang out together, near the nest at first,

then venturing further out. The parents will keep bringing food to the young, at least occasionally through the summer and into early fall. Some young owls might still beg for food from their parents well into October. At that point, mom and dad are probably thinking, You can beg all you want, but we already taught you how to catch your own dinner. Our work here is done. Time for you to move out and get a job, son. The young owls become more solitary, spending less and less time with their siblings. They eventually all disperse from their parents' territory. Having no territories of their own yet, they become, quote-unquote, floaters for a few years. Eventually, if they're lucky, they find love, pair up, and establish their own territories.

In asking her question about these owls, Kate was especially curious about the vocalizations of the young. The chicks and fledglings make a variety of sounds, but the begging call is loud and distinct. It's a single-syllable raspy screech. I got familiar with this strident sound myself this past summer. We have some forest in the backyard, and we had a resident family of great horned owls. I would hear that screech over and over after sunset, out in the dark forest. It made me happy every time. Anyway, young male owls start practicing their hooting call at an early age,

but they won't perfect their hooting until their footing. first spring at the earliest. Here's our other question about owls. Audra Halleck wrote, Maybe you could talk about their silent flight. How do they do that? If hawks and eagles are like the samurai warriors among raptors, owls are more like ninjas.

Owls hunt in the dark and they rely on stealth and sneak attacks. It's not always obvious to us, but most bird wings, make noise when they flap. Owls fly slowly enough that the fuzzy little mammals they eat would hear them coming from a long way off. Nocturnal mammals have excellent hearing. So amazingly, owls have evolved the superpower of silent flight. A suite of adaptations makes this possible. First off is simply the ability to fly slowly. The less you have to flap your wings, the less noise you're going to make. Slow flying requires broad wings, and low wing loading.

In other words, not much body weight and a large overall wing area. Such is true for owls. This also makes gliding easier. No flapping is necessary at all for gliding. Next are the tiny serrations on the feathers of the wing's leading edge. These comb-like structures reduce noise.

And then there is the overall velvety texture on the owl's wing surface. Tiny hair-like filaments on the feathers create this texture. The result is something like a soft, fuzzy blanket feel. I hang soft fuzzy blankets around me when I record podcast episodes, as in like this very moment. Blankets dampen sound, and the fuzzy ones work nicely. So there are serrations on the wing's leading edge,

and there's the overall velvety texture. The trailing edges of owl wing feathers also have a special shape. They're fringed. Most flight feathers and birds have a clean, crisp edge, but owl feathers look sort of ragged. This too helps these avian ninjas stay silent. The primary functions of these structures, as I understand, are to absorb sound and reduce air turbulence around the wing.

Less turbulence means less noise. Just like the woodpeckers we were talking about earlier, owls have inspired some human engineering projects. At least on paper, researchers have designed wind turbines and propellers that borrow features from owl feathers. These structures would be not only much quieter, but also more efficient. I'm not sure if any of these have been built yet, but the idea seems pretty cool. Emily Hickman had a question about what's going on with brown pelicans when they are flying together in formation out over the ocean. We talked a little bit about this in episode 37, about how birds fly.

The example I gave was geese, but the same principles apply to brown pelicans. Besides trying to look cool and succeeding, pelicans fly in a V formation to minimize the energy they need to burn. A bird's wing in flight creates these little vortexes or vortices in the air. These cause drag and make flying harder. flying immediately behind your buddy you are going to get hit with some turbulence from the other bird's vortices but if you move off to the side just so you can actually benefit from the situation that's because the swirling wake coming off of the other bird when it's on the upward part of

the swirl it pushes up on your wing it can actually make flying easier less energetically expensive for you. There was this super cool study looking at northern bald ibises, published in 2014. The researchers attached little GPS trackers to a bunch of ibises and gathered data on their relative positions during flight and formation. It turned out the birds placed themselves in just the right spots to gain maximum aerodynamic benefits. These and other formation flying birds also stagger their wing beats in time to catch the updraft of the leading birds wake vortex. This is truly an amazing ability. Birds are awesome people. I know I'm preaching to the choir, but birds are awesome. The next question comes from Craig Williams. If that

Name rings a bell. It's because Craig is the artist from Tasmania who is doing some paintings for the science of birds. We're offering these paintings for sale in the online shop and donating 50% of the profit to bird conservation. So that's Craig. He's also one of my supporters on Patreon. And here's his question. Can you comment on the recent news in the U.S. about the government listing a number of species as extinct? This question refers to the announcement made by the U.S. Fish and Wildlife Service on September 29th, 2021. The agency said they are proposing to remove 23 animals and plants from the endangered species list. Not because of anything good, mind you. Not because these species have recovered and are doing fine. No, it's the opposite.

These species are now considered extinct, gone from the world, at least in the eyes of the federal government. Most of the species were birds, 11 of them. And of those, eight were found only in Hawaii. The other three bird species are Bachman's Warbler from the southeastern U.S., the bridled white eye from Guam, and the ivory-billed woodpecker, also from the southeastern U.S. It's rare that the Fish and Wildlife Service makes a sweeping announcement like this. They don't often just give up on a species and delist it, or in other words, remove it from the endangered species list.

Since the list became official in the 1960s, only 11 other species have been removed for the reason of extinction. So it was a shock to hear that 23 more species are now considered lost causes. The Fish and Wildlife Service says this move will help free up resources, time and money, for the conservation of endangered animals and plants that we can still save. Are these 23 species really truly extinct? For most of them, the answer seems to be an unequivocal yes. They're gone. Scientists and federal agents have done their surveys and their searches, and it's clear.

But the ivory-billed woodpecker is another story. This species is the one that got the most attention from the media after the recent announcement from the government. The ivory-billed woodpecker, Campapilis, principalis, is, or was, I guess, a gorgeous, black, white, and red bird. It was the largest woodpecker species in the U.S. And it lived in old-growth, swampy forests of the southeast. There hasn't been a confirmed sighting of an ivory-billed woodpecker in the U.S. since 1944.

But the thing is, there have been a bunch of unconfirmed sightings, well into the 2000s, some of them from legit, reputable scientists. In 2004, an expedition by the Cornell Lab of Ornithology reported seeing and hearing. ivory-billed woodpeckers in Arkansas. The researchers from the lab ended up getting their work published in the prestigious journal, Science. The news headlines proclaimed

the ivory-billed woodpecker still exists. But the scientific evidence, while intriguing, wasn't super convincing. Not to everyone anyway. And since 2005, no one has found one of these birds. The primary author

of that paper in science was John Fitzpatrick, the former executive director of the Cornell lab. He says that the move by the U.S. government to give up on the woodpecker is premature. Fitzpatrick believes there could still be a few ivory-billed woodpeckers hanging on out there, somewhere way back in a remote swamp. And he's right, there's a chance, however slim, that this amazing bird still lives. This makes me think about Bigfoot, the huge ape-like creature that supposedly stalks the forests of the northwest. like right in my backyard.

Tons of people claim to have seen Bigfoot. There are entire podcasts dedicated to this mythical creature that definitely does not exist. Multiple podcasts, mind you, a couple of which are more popular than this one. It's hard to imagine any podcast being more popular than mine, but seriously, Bigfoot? Proving that something exists is relatively easy. To prove that the ivory-billed woodpecker still exists, you need to be able to. to find just one bird or one piece of irrefutable evidence. Same goes for old Bigfoot. Show me one Bigfoot and congratulations you have proven the creature's existence.

But proving the non-existence of something is a lot harder, especially when you're looking for it across a vast area. You can search and search and search for your beast of interest, find nothing, and still claim that it might be out there somewhere. We just need to to look harder. I mean, I can prove there are no ivory-billed woodpeckers in my living room. I wish it weren't true, but sadly it is. I've looked and can't find any. But proving with 100% certainty that none of these birds still exists in the wild, that may be impossible. But I suppose the certainty of the woodpecker's extinction will creep closer to 100% as more decades pass without anyone seeing one.

I can understand the proposal to delist the ivory-billed woodpecker. It's super sad, but I think it makes some sense. If funding and other resources were infinite, then sure, we could keep hope alive. We could preserve the bird's habitat and just keep searching for it. But unfortunately, resources are very much limited. The Fish and Wildlife Service is practicing triage here, right? They're giving up on some species that are almost certainly extinct, while redirecting their energy to help species that have a fighting chance.

It's sad that such decisions have to be made, but that's the situation we're in. Let's just hope this is the last time the Fish and Wildlife Service makes an announcement like this. Unless they declare Bigfoot is extinct, I'd be okay with that. Our last question today comes from Chris Bishop. She asks, I saw a blue jay at my feeder with no tail feathers. How did this happen?

Why could he still fly? And what is the chance he will survive? This is something I imagine many of us have seen in our backyards, a songbird that has no tail whatsoever. These birds look pretty goofy and also adorable. There was recently a spotted tohi hopping around in our backyard bushes that was missing its tail. We named it All Ball.

That's what Coco, the famous sign language using gorilla, named her pet kitten, All Ball. It was a good name because the kitten had no tail. So what happened to the tales of Chris's Blue Jay and All Ball, our spotted Tohi? One possibility would be that these birds were simply molting as part of their annual cycle. Perhaps they shed their tail feathers as new ones were growing in. Nope. That's probably not what happened.

Dropping all the tail feathers at once isn't what normally happens in songbirds. If that was the norm, we'd see birds without tails all the time, wouldn't we? The tail feathers, technically called retracies, are shed in pairs. It's usually the central two feathers that are replaced first. Then the next pair outward grows in, and so on. It's an orderly progression. The process takes several weeks. the bird has a functional tail the whole time.

But what is the function of the tail? If we ignore things like looking pretty for the purposes of sexual selection, yes, I'm looking at you, Mr. Peacock, then the function of the tail is for flying. It provides extra lift. It reduces drag and increases maneuverability. But it's not essential for getting off the ground. Our blue jay and spotted tohi can still get around by flying,

just not as efficiently as they normally can. My guess is that these individuals were attacked by a predator. A house cat, maybe, a sharp-shinned hawk, or maybe Bigfoot. I mean, we can't prove that it wasn't Bigfoot. You see, there's something called Fright Malt in birds. They have certain feathers that detach with relative ease if grabbed. This is true for feathers on the back, rump, and tail. Those are the parts of the body most of the body most of the same.

likely to be attacked by a predator. So a cat pounces on a blue jay, gets its claws on the tail feathers, and pop, all the tail feathers fall out at once. That's fright mold. The cat is confused and ashamed of itself, and the bird escapes. Close call. As long as it stays safe for a few weeks, our bird will grow a new tail and hopefully have a long, happy life.

Looking ridiculous without a tail, for a short time, is a little bit of a short time. a small price to pay for survival. This was a fun episode to research and put together. You never know what sorts of interesting questions people are going to ask. And there are endless questions to ask about birds, aren't there? I learn a lot in this process too. That's one of the great joys I have in producing this show. I don't have all the answers floating around in my brain,

so I do my homework and I learn. I don't know about you, but I feel lucky to live in the information age. It's wonderful to have so many resources at our fingertips, but it can also be overwhelming, and it's sometimes difficult to sort out the good stuff from all the garbage and fake news. I feel like one of my roles here is to help filter and distill knowledge about birds and nature

and then to serve up the good stuff to you. in the best way I can. Thanks again to my helpful Hornbill patrons who submitted excellent questions for this episode. We'll do it again sometime. If you are curious about what it means to be a patron of this show, you can check out my Patreon page over at patreon.com forward slash science of birds.

If you have something you'd like to share with me, go ahead and shoot me an email. My address is Ivan at Scienceofbirds.com. Maybe you have some thoughts about the podcast you want to share. Or perhaps you want to tell me the story of that time you were pretty sure you saw Bigfoot and an ivory-billed woodpecker smoking cigarettes in a Walmart parking lot. The show notes for this episode, which is number 39, can be found on the website, scienceofbirds.com.

I am, as always, Ivan Philipson. Thanks so much for listening and I'll see you next time. Cheers. Thank you.