The Science of Birds - House Sparrow

Episode Date: March 21, 2024

This episode—which is number 93—is all about the the House Sparrow (Passer domesticus), one of the world’s best known and most abundant birds. It expanded across the planet along with humans over the last 10,000 years, with the spread of agriculture. Today, this plucky little bird is a model organism for the study of basic bird biology. Over 7,000 scientific studies of the House Sparrow have been published. In this episode, we’ll get into what this species looks and sounds like, where it lives, its behavior, its breeding biology, and more.Links of InterestWorld Sparrow Day~~ Leave me a review using Podchaser ~~Link to this episode on the Science of Birds website Support the show

Disneyland is a weird place. I grew up near there in Southern California, so as a kid, I got really familiar with rides like the Jungle Cruise, Pirates of the Caribbean, and the Haunted Mansion. I'll admit, I used to love going to Disneyland. But yeah, it's weird. It's teeming with all these animals and fantastical creatures that are 100% fake.

They're puppets or roe. robots made of plastic or metal or concrete. When you visit Disneyland, you're supposed to suspend your disbelief so that all those fake things seem kind of real. But unless you're a four-year-old, it's hard not to see the facade for what it is. So I guess that's why I have this memory from when I was a kid. I remember being amazed to see real live songbirds hopping around on the ground at Disneyland. These small living animals were a striking contradiction to their mostly artificial surroundings.

Now, no doubt you've seen the title for this podcast episode, so you know where I'm going with this. Those Disneyland birds were house sparrows. I remember them chirping and begging me for French fries, as is the custom of their kind. As a naive kid, I thought those houses. sparrows at the Magic Kingdom were quote-unquote wild birds. I had no idea what species they were and I didn't know their backstory. And oh boy, does the house sparrow have quite the backstory. 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 93, is all about the house sparrow, passer domesticus. We'll get into what this species looks and sounds like, where it lives, its behavior, its breeding biology, and its opinions on several hot-button political issues. The choice of species for this episode was made by my awesome supporters on Patreon. A few weeks ago, I sent them a poll asking them to cast their votes. The choice was between the house sparrow and the Canada goose. I was kind of surprised that the sparrow had a landslide victory.

It blew the goose out of the water with 61% of the vote versus 39%. Does this result tell us how excited people are? to hear about house sparrows? Or does it tell us more about how much some people dislike Canada geese? Like maybe those people think the house sparrow is the lesser of two evils. Who knows? Well, I'm sorry to tell all you goose haters that the Canada goose will indeed get its own podcast episode. Someday.

Voting in polls like this is one perk that my supporters get. So if you would like to wield the godlike power of condemning one bird species while celebrating another, or by choosing the lesser of two evil birds, please consider becoming a member of my Patreon community. You can do that by going to patreon.com slash science of birds. There's also a link in the show notes on your podcast app, a link that says support the show way down at the bottom. All right, Passer Domesticus, the House Sparrow. This is one of the most ubiquitous and familiar bird species in the galaxy. There's an enormous number of these birds flying and hopping around.

Bird Life International gives a rough estimate of the species' global population as between 900 million and 1.3 billion mature individuals. For comparison, consider that another wide. spread bird, the rock dove, aka the feral pigeon, has an estimated global population of only 260 million. Like pigeons, many people seem to take house sparrows for granted. They're just ubiquitous urban birds, something to be ignored as part of the background noise of city life. Or some people actively despise these birds. For example, one biologist in 1912 wrote that the house sparrow of among birds, like the rat among mammals, is cunning, destructive, and filthy. We'll touch upon

the reasons many people dislike this species along the way today. One group of people that hasn't taken house sparrows for granted is scientists. Passer Domesticus is one of the most well-studied birds of all time. There have been over 7,000 published scientific studies on this species. The house sparrow has become a model organism, a model for studying the basic biology of birds. One reason this species makes a great model is because of its geographic variation in things like body size, plumage color, metabolic rate, immune defense, and clutch size. Traits like these vary among sparrows in different habitats and at different latitudes and between introduced populations and their native source populations.

The house sparrow is also a good model organism for practical reasons. These birds live close to humans pretty much everywhere. They're relatively fearless around people and they're super abundant. Today may not be the day I distill and explain to you everything there is to know about the house sparrow based on those 7,000 scientific papers. Nevertheless, I'll do my best to tell you more than you, probably ever wanted to know about this plucky little bird. As always, when talking about a single bird species, we begin by describing its appearance,

as well as a few behavioral traits and the sounds it makes. Now, I'm just guessing, but you can probably already picture what a house sparrow looks like. But for the sake of being thorough, let me do a quick review. These are stout little birds with thick cone-shaped bills. Beak to tail, they're about six to seven inches or 15 to 17 centimeters long. In terms of plumage, the male is more boldly patterned and more colorful than the female. During the breeding season, the male has a black beak and lures, a chestnut-colored neck, white or pale gray cheeks, a gray crown and a black bib running from his throat down to his breast. There's also a little white dot just behind each eye, or more technically we'd call it

a post-ocular spot. The male's back is a rusty brown color with black streaks. The underparts are gray. In the non-breeding season, the male's bill isn't black. Instead, it's light gray with a yellowish base. The black bib is also much less conspicuous in the non-breeding season. I say less conspicuous because the bib is actually there in the non-breeding plumage. It just hasn't been revealed yet. Adult house sparrows molt once a year in late summer or early fall. At first, the fresh feathers of a non-breeding male give him a relatively dull appearance. He lacks the bold black bib. But as the months go by and spring approaches, the male's plumage becomes more and more richly colored and more boldly patterned. Without any further molting, the bib

appears. What's going on here? Well, these changes result from the way the feathers wear down over time. The tips of the bib feathers, for example, are gray or white when they first grow in. The black parts are concealed underneath. But as the little sparrow lives its rough and humble life between fall and spring, those pale feather tips get worn off through abrasion. And behold, there is the glorious black bib. It was there all along. The female house sparrow does not have a bib. Her upper parts are a brownish buff with some black, brown, and buff striping. Her underparts are gray. There are no black markings on the female's head, but she has a buff-colored stripe running behind her eye. One reference I came across

pointed out that, compared to how sparrows living in pastoral agricultural agricultural environments, like on farms, the ones living in cities tend to have feathers with a, quote, dull, unkempt appearance. Unkempt as in disheveled, scruffy, bedraggled. I guess because life for a sparrow on the streets is hard? Because in the concrete jungle, survival is a daily battle against rats, feral cats, cars, disease, and pollution? There have been some scientific studies highlighting the connection between feather quality and the degree of urbanization in house sparrows. For example, researchers studying sparrows in France found significantly higher levels of the stress hormone corticosterone in the feathers of juveniles born in cities.

This suggests that chicks raised in urban environments may suffer from lousy growth conditions. Maybe they have lower quality food than their cousins living out in the countryside, or they might experience more frequent threats from predators. Regardless of whether house sparrows are living on a farm out in the country or in the shadows of skyscrapers, these birds tend to be gregarious. They breed in little colonies and move around in some. small flocks during the non-breeding season. And this brings us to look at a few aspects of house sparrow social behavior.

Within a flock of house sparrows, there's a pecking order, a dominance hierarchy. If you want to learn more about this topic, I did an entire podcast episode on pecking orders or dominance hierarchies. That was episode 48. So some individuals in the house sparrow flock show dominance by intimidating or beating up their subordinates. A significant number of those 7,000 research papers on house sparrows have tackled questions related to dominance and competition within flocks of this species. In general, it seems that the most dominant males, the top dogs, are the ones with

the largest black bibs, and these tend to be the older males in the flock. Subordinate males with smaller bibs often avoid challenging the dominant males. When a subordinate male sees another male across the room wearing an impressively large bib, he avoids eye contact and keeps his distance. And that's going to be my survival strategy if I go to prison. When I go to prison? Instead of keeping an eye out for scary prison dudes with the largest black bibs, I'm going to avoid the ones who have the most face tattoos and the ones with the creepiest staring eyes. You know, the sociopathic ones? Anyway, with house sparrows, a dominant individual will make threats when it feels the need.

It faces its opponent and holds its body in a horizontal posture. The head is pushed forward and the beak is wide open. If that doesn't cause the other bird to back off, the threatening male may kick it up a notch by showing off the black and white markings on his wings, and by generally fluffing up his feathers. If the other bird still isn't getting the message, because of stupidity, perhaps, or a brazen attempt to improve its own social status,

then it might be time to throw down. The dominant male making the threat display switches into attack mode. He pecks at his rival and bites the other bird on the nape or wherever he can reach. The birds may leap into the air and engage in fluttery aerial combat with claws and beaks, or they may scuffle on the ground. In rare cases, a fight like this can end up with one bird severely injured or even dead. But more often conflicts are avoided, because subordinate birds simply respect the bib, or they back down after the first threat display.

Female house sparrows, too, are pretty tough little birds. They can also take on a dominant position in the flock. Multiple scientific studies on the roles of female sparrows in the dominance hierarchy have produced some conflicting results. So it's a little unclear how this all works with females. In some populations, females show dominance year-round. In other populations, they're dominant only in the breeding season, or only under certain conditions. In any case, they can sometimes hold their own. against the larger dominant males.

One social activity that house sparrows seem to enjoy is bathing together, in water or in dust. These little buggers take dust baths all the time. They squat or lay on the ground and wiggle their heads and their bodies around rapidly, rubbing themselves with dust. They flutter their wings to throw dust onto their backs and tails. It's pretty cute to watch. Just search YouTube for house sparrow dust bathing, and you'll see what I mean. Dust bathing is a form of self-care for birds.

It allows a bird to get rid of parasites and flakes of dry skin, and it helps to keep the feathers from getting too greasy from preen gland oil. After some vigorous dust bathing, a house sparrow ends up excavating a shallow crater or wallow for itself. This little depression in the dirt is something worth defending, apparently, because the crater maker will often make a threat display to any other nosy sparrow that hops too close. Okay, let's move on to listen to the sounds of the house sparrow. The song of Passer Domesticus is a rather simple vocalization, at least to our human ears.

It's called the cheap song, not cheap as in a cheap date or a cheap trick. Cheap in the case of the sparrow song is spelled C-H-E-E-P, not C-H-E-A-P. Some field guides or other publications describe this song as chirp, chirp, chirp, cheer-up, all of those could work. I mean, have a listen to these sparrows and decide how you would spell their songs as written words. I heard several different sounds in that recording. There was chirp, chirp, and cheer up for sure.

And isn't that nice, the birds are saying, cheer up. They're like, hey there, human friend, cheer up, life ain't so bad. Turn that frown upside down. Cheer up. But don't you step one inch closer to my dust crater or I swear I will murder you. The house sparrow belongs to the avian family, Pasuridi.

This group is known as the Old World Sparrows. Passer Domesticus is one of about 43 species in the family Passerity, and there are 27 other species in the genus Passer. This word, passer, comes from Latin, and it means, you're not going to believe this. It means sparrow. Now again, this is an old world sparrow. It's not all that closely related to New World Sparrows. The latter are in the family Passerrellae. You got that? It can be a little confusing. Old world sparrows are in the family Passeridae.

New World sparrows are in the family Passerrellity. Even though the house sparrow is technically an old world sparrow, we find them swarming all over the new world, including at Disneyland in Orange County, California. You probably already know the reason for this, but if not, don't worry, we're getting to it. For the moment, let's consider which birds are the ones. the closest relatives of the house sparrow.

An updated evolutionary tree, aka phylogeny, for the Old World Sparrow family, was published in 2021. It's based on genetic data from DNA. This tree revealed that Passer Domesticus, the House Sparrow, is most closely related to three other species, the Spanish Sparrow, the Italian Sparrow, and the Socotra Sparrow. The house sparrow shows some geographic variation in plumage and body size across its natural range. Passer Domesticus, the species, is divided into 11 sub-species. The particular subspecies we have here in North America is Passer Domesticus, Domesticus. These birds originated in England and Germany.

There's another subspecies that I find especially interesting. Passer Domesticus Bactrianus. These birds have a very different way of life compared to those belonging to the 10 other subspecies. The Bactrianus subspecies is found in parts of the Middle East, Central Asia, Pakistan, and China. The root word bactrian here, also applied to the two-humped camel, refers to an ancient country in Central Asia,

a country named Bactria. Unlike all other house sparrows, the Bactrianus subspecies is migratory. These birds spend their winters in India, for the most part. Perhaps even more interesting, this subspecies doesn't really hang out with humans. Bactrianus sparrows breed in natural habitats, like the banks of rivers flowing through grasslands. These house sparrows are more fearful around humans, and they don't want anything to do with houses. Now, the next time you find yourself at a fancy cocktail party and you're trying to meet new people and make some friends, you will no doubt be eager to tell them about this

fascinating subspecies of the house sparrow. But there's a problem, isn't there? Saying Bactrianus out loud might make you feel silly or nervous. Maybe you're worried about everyone at the party pointing and laughing at you in mockery. To my knowledge, Bactrianus is the quote-unquote, correct pronunciation. However, to save yourself from a social disaster, you could just pronounce it Bactrianus. Bactrianus, Bactrianus, whatever you're comfortable with.

At the beginning of this episode, I implied that the house sparrow has an interesting backstory, an interesting origin story. So let's get into it. Once upon a time, there was a sparrow species hopping around in the Middle East. This was the ancestor of the modern house sparrow. The earliest fossils paleontologists have unearthed for this bird are tens of thousands of years old, and they were found in Israel.

Paleontologists found an even older fossil dating to several hundred thousand years ago in Palestine. The guy who discovered this fossil named the ancient bird, Passer Pre-Domesticus. Passer-Pre-Domesticus, making the case that this was the wild ancestor of today's passer-domesticus. Alongside those ancient sparrows in the Middle East, there lived a species of bipedal naked ape. Around 11 or 10,000 years ago, this clever ape, Homo sapiens, figured out how to domesticate some food plants. It had invented, agriculture. And that changed everything for our little sparrow. With the rise of agriculture, there was a nutritious and plentiful new food source in the form of domesticated grass seeds,

in other words, grain. Some of those ancestral house sparrows learned to gorge themselves on the grain that humans left lying around on the ground. The birds also learned to build their nests close to humans, in little nooks and crannies in man-made structures. Over time, they lost their fear of humans. As agriculture spread outward from the Middle East, the sparrows too spread across Europe and Asia. But not all of those original sparrows in the Middle East, cosied up to humans and adapted to a life that depends on agriculture. Some of them remained wild and free. Ornithologists think that the subspecies passer domesticus Bactrianus that exists today is closest to the ancestral form of the house sparrow. And yes, I'm sticking with the anus pronunciation. I hope you can

handle it. Sparrows of the Bactrianus subspecies still live in their ancestral homeland in parts of the Middle East and Central Asia, and they still migrate long distances every year. I imagine them as stoic birds who hold fast to their traditional values and their customs. Choosing hard work and clean living over the easy life, they look down on their lazy, human-loving cousins who were too soft and weak to resist the seductions of free grain and cheap housing. Those human-loving sparrows, all the other house sparrow subspecies out there, have co-evolved with us over the last 10,000 years or so. They've become what biologists call commensal animals,

C-O-M-M-E-N-S-A-L, commensal. In a commensal relationship between two species, one of them benefits without harming or helping the other. House sparrows get the benefits of food and shelter from us, and they don't really bother us all that much. as long as you don't mind monotonous incessant chirping. The house sparrow depends on humans so much that some scientists call this species an obligate commensal. Obligate meaning that it has no other way to live.

It can only survive as a commensal species in environments created by humans. When people abandon a town or village, the local house sparrow population will often go extinct. There are other birds out there with the word house in the common name. House Wren, House Finch, House Swift, House Atreides, House Lannister, and so on. But the House Sparrow is the only bird species in the world that has the word domesticus in its scientific name. Just an interesting fact that I thought I'd add here.

Research using genomic data from house sparrow DNA revealed evidence of recent natural selection in this species. A study published in 2018 in the journal Proceedings of the Royal Society B highlighted a couple of interesting genes in the house sparrow genome. In the human-dependent subspecies, one of these genes appears to have produced a thicker skull and beak. better for cracking open agricultural grains, perhaps. The other gene is for an enzyme that helps with digestion in high-starch diets. Again, because of the grain. In contrast, the genomes of the ancestral bacterianus sparrows

don't appear to show such evidence of adaptation to life among humans. I'm going to move on now to talk about the distribution and habitat of the house sparrow. There are two versions of the distribution map we can picture for this species. First, there's what we might call the natural or native distribution. If we were to travel back in time several hundred years, we'd find house sparrows across most of Eurasia, from the British Isles all the way to eastern Siberia. Their natural distribution also included Northern Africa, the Middle East, India, and Southeast Asia.

Then there's the map of everywhere this bird is found today, including all the places it's been introduced by humans. This map includes the bird's native distribution I just talked about, plus everywhere else. House sparrows have been introduced to North and South America, Southern Africa, Australia, New Zealand, and other islands like those of Hawaii. These little buggers are all over the place. Okay, so they don't live everywhere. For example, they seem to know better than to live in Antarctica. Then again, there are house sparrows way up in the frigid Arctic of Scandinavia.

So maybe if there were some larger permanent human settlements in Antarctica, some hearty little house sparrows would set up shop there too. Who knows? So, the epic saga of the house sparrow didn't end thousands of years ago when these birds finished spreading across Eurasia with the rise of agriculture. Their domination of the rest of the planet happened much more recently. In North America, for example, there have apparently been well over 100 intentional or accidental introductions of house sparrows.

People brought them here from Europe. The first introduction to North America was in Brooklyn in about 1851. That was followed by more introductions and the birds began to spread on their own. By 1900, they were chirping triumphantly across the entire continent. But they still haven't gotten very far into Alaska or the far north of Canada. So backing up, why did someone dump a bucket full of sparrows onto the streets of Brooklyn? New York? And what about all those other introductions in North America? What were these people thinking? One reason was that some people who had emigrated from Europe missed seeing familiar

European songbirds like the house sparrow. They wanted to have some around. And a seemingly more practical reason was to control pests. With those sparrows released in Brooklyn, for example, the hope was that they would eat linden moth caterpillars that were munching on trees in the city. In the mid-1800s, many people in North America were all jazzed about having more

and more house sparrows around. But as the birds spread aggressively and their population exploded, the public attitude toward them eventually did a 180. They came to be seen as pests, nuisances. Some cities offered bounties for dead house sparrows.

But accidental introductions continue around the world. House sparrows have apparently arrived on distant shores as stowaways on ships. I haven't seen any house sparrows on ships, but I have seen them flitting around inside airports. You probably have too. With a climate-controlled environment, plenty of crumbs and food scraps around, and nooks for nesting, sparrows can potentially live in an airport for a long time. But I think I know what they're really up to. These cheeky birds have decided, like most humans,

that intercontinental travel by ship is just too slow. Those airport sparrows are just waiting for an opportunity to sneak onto a plane. They don't care where it's going. They just want to go somewhere, anywhere, as long as there's some dust to bathe in and some humans to irritate. It'll be like a sequel to the 2006 movie, Snakes on a plane, starring Samuel L. Jackson. This time, it'll be Sparrows on a plane.

An action-packed thrill ride critics are calling The Best Movie Ever Made about small birds mildly annoying people on a commercial aircraft. Rated PG-13 for intense sequences of avian action, disturbing content, some strong language, and pervasive chirping. Okay, so far we've looked at the distribution of the house sparrow. How about its habitats? As obligate commensals, most house sparrows breed in or near human structures. They live on farms or in other agricultural settings where there are plenty of loose cereal grains lying around.

But they also thrive in suburban and urban areas. Even zoos and amusement parks make for some great house sparrow habitat. Besides airports, these birds will also live and breed inside malls, grocery stores, factories, churches, Walmarts, and the Home Depot. So maybe we should ask, where don't we find these birds? House sparrows have a hard time surviving in remote, wild places far from humans. That means we don't find them in forests, grasslands, deserts, or alpine wilderness. But if there's even one lonely gas station or a farmhouse in an otherwise barren landscape,

there's probably a little flock of house sparrows living there. These birds are so good at colonizing isolated human settlements, I wouldn't be surprised if some of them have already infiltrated the international space station. And if these sparrows follow humans as we build spaceships and expand outward to the stars, maybe they'll evolve into a new species. We can name it Passer Galacticus. The conservation situation with the house sparrow is complicated. For people living in places like the United States, Argentina, or New Zealand, the bird is a non-native pest.

They're a problem. On the other hand, the sparrow is a cherished native species in places like the UK, mainland Europe, the Middle East, and India. The International Union for the Conservation of Nature places the House Sparrow in the least concern category at the global scale. That's no surprise since this is one of the most abundant bird species on the planet. Remember that there are somewhere between 900 million and 1.3 billion of them. Despite the House Sparrow's enormous population and enormous distribution, it's been having some problems. Data from the North American breeding bird survey showed that the population on this

continent plummeted by 80% between 1966 and 2019. In the UK, the house sparrow is still the most commonly observed garden bird. But there too, the population has declined dramatically. It's dropped by at least 70% since 1977. The Royal Society for the Protection of Birds gives the house sparrow a conservation status of red in the UK. And in case you're wondering, red is bad. Scientists still aren't sure what's causing the decline of house sparrows in some parts of the world. Hypotheses include a reduction in grain or insects that the birds eat, increasing pollution, loss of nest sites, increasing disease, and increasing pressure from predators like hawks. Now, maybe you can't be bothered to shed a tear for a species declining in places where it isn't native,

places where it's considered a pest. I can understand that. All the same, we should probably pay attention to what's happening to the house sparrow and try to understand the causes of its decline, because the same things might be affecting the birds that we do appreciate, the native species we definitely don't want to lose. But if you're worried about the plight of the house sparrow in particular, one thing you can do is celebrate World Sparrow Day. It's on March 20th every year. And get this, it is 100% a total coincidence that the day I'm publishing this podcast episode is March 20th. Until I was researching this episode, I had no idea there was such a thing as World Sparrow Day.

Quoting Wikipedia, World Sparrow Day is a day designated to raise awareness of the house sparrow and the other common birds in urban environments and of threats to their populations. End quote. So happy World Sparrow Day, everybody! You know, I looked at a lot of photos of house sparrows. as I was writing this episode.

In a bunch of those photos, the sparrow had little bits of food crud stuck to its beak. It cracked me up. It was like the photographer had just caught the sparrow with its face in a pile of garbage or something. Of course, the bird looks like it has no shame. It couldn't care less. It's like,

What are you looking at, human? I eat whatever I want. You're the dummy that threw away all these delicious scraps. It's like they say, one man's trash is another sparrow's treasure. Garbage is on the menu because the house sparrow is an opportunistic omnivore. Now that said, its primary diet is seeds. More specifically, grains, including domesticated cereal grains like corn, wheat, and oats, but also grains from wild grasses, and they'll eat weed seeds too. House sparrows are persecuted as agricultural pests in

many places because of their love for domesticated grains. Other kinds of plant material in the house sparrow diet include berries and other fruit and buds. In the spring and summer breeding season, insects make up about 10% of the diet. Other small animals sometimes end up in the bellies of house sparrows too. Worms, slugs and snails, small frogs and lizards, and even crustaceans. And since this species is an obligate commensal, or as some scientists put it, an anthro-dependent species, it eats plenty of food that it gets from humans.

This could be birdseed from feeders or breadcrumbs, pizza crust, or those pieces of ravioli that you left on your plate after you had lunch on the patio at the Italian restaurant. How sparrows forage by hopping around on the ground, looking for seeds, or whatever. In some places, flocks of house sparrows descend upon backyard bird feeders and end up dominating the scene. They stuff their little beaks with seeds and can prevent native birds from getting their fair share. Many predators eat house sparrows. In North America, the list of avian predators includes species like Cooper's Hawk, Sharp Shinned

Hawk, Northern Harrier, Merlin, American Kestrel and Loggerhead Shrike. Other animals known to kill house sparrows include cats, dogs, and snakes. And humans. People have been eating house sparrows for

hundreds, if not thousands of years. People in Europe used to hang so-called sparrow pots from the eaves of their houses. The birds would come along and build nests in the pots, then people would scoop out the nestlings and eat them. Yikes, that's kind of rude. But yeah, sparrow dumplings and sparrow pie used to be a thing. And I guess some people in the Mediterranean region still eat house sparrows today.

Our last major topic today is the breeding biology of Passer Domesticus. This species is socially monogamous. They tend to pair up for life. However, there's often some mating on the side with birds outside of the pear bond. courtship behavior is important for the formation and maintenance of breeding pairs. Females appear to choose males with the largest, darkest black bibs. This role of the bib as a signal in sexual selection is the most recent explanation for the bib's existence and for its variation. Now, I know I was joking around earlier about the male sparrows being sort of like human males in prison.

the idea that subordinate males avoid challenging dominant males with larger bibs is sort of the old way of looking at this biological situation. We used to think the bib was a signal of social status. More recent research has revealed that bib size may not be as important for avoiding conflict among sparrows as ornithologists once thought. In any case, when a male house sparrow wants to work, win the heart of a lady, he puts on a little show for her. He fluffs up his bib and chest feathers, opens his wings a bit, spreads his tail feathers, and hops all around the female.

Established pairs maintain a small territory centered on their nest site. They defend the territory fiercely in the breeding season, but they're more chill about the whole thing at other times of the year. If an outsider gets too close during the breeding season, the territory holding pair will chirp loudly and chase the intruder away. House sparrows don't just show aggression and attack members of their own species. They've been recorded attacking at least 70 other bird species. They do this to defend their own territories, or they will also forcibly evict other bird species from their nests. For example, house sparrows will sometimes enter the nest of a bluebird, swallow, or martin, and throw that bird out of its nest. The house sparrows just take

over. The fact that non-native house sparrows steal the nests of native birds like this is another reason many people dislike them. As a commensal species, house sparrows prefer to build their nests in man-made structures. They set up shop in little nooks and crannies in buildings, walls, neon signs hanging outside of fast food restaurants, and so on. Apparently, there was even a sparrow colony breeding in a coal mine, 2,000 feet or about 670 meters underground.

Crazy. In general, this is a cavity nesting species. They'll also use natural cavities in trees, or on cliffs. The nest itself is a messy jumble of sticks, grass, and leaves on the outside, and it's lined with feathers and other soft items on the inside. A clutch of four to five eggs is typical. It's also typical for house sparrows to lay two to seven clutches every breeding season. So these guys really crank them out. Both parents sit on the eggs and both help to feed the growing chicks. Baby house sparrows are altricial.

They have no feathers when they're first born and their eyes are closed. They're basically helpless. But in about two weeks, the little guys are ready to leave the nest. By that time, they can already fly. And off they go, chirping their hearts out and scouring the land for grain and table scraps. Only about 20 to 25 percent of young house sparrows will survive their first winter. Lifespan in this species is probably just a few years, but some have lived almost two decades in the wild and about 23 years in captivity. The sparrows that do survive their first year or so

will look for a mate, then settle down to breed. Most house sparrows are residents. They live in more or less the same small area all year long. An individual might stay within a range of only about a mile in radius, somewhere between one and two kilometers. I have mixed feelings about house sparrows. On the one hand, they're cute, interesting birds with lots of personality. But I'm not a fan of any non-native or invasive species. I know it's not their fault, but still. I'd be happy to see a flock of house sparrows in Eurasia, where the species is native,

but seeing them in Disneyland or inside an airport or at a bird feeder in North America, not so much. No me gusta. People in many parts of the world hate house sparrows for being non-native agricultural pests, and because these birds compete aggressively with native birds for food and nest sites, because they're destructive and filthy. Ned Deerborn, the biologists who said that about them way back in 1912, also wrote this. Quote,

The English Sparrow, that's another name for the House Sparrow, the English Sparrow defiles private and public property, fights and dispossesses useful native birds, replaces their songs with discordant sounds, and destroys fruit, grain, and garden truck. end quote. Wait, truck? Does he mean that

House Sparrow's went around destroying trucks? Like did flocks of them attack vehicles on the highway, pecking at the eyes and hands of their drivers, causing the trucks to run off the road and crash in fiery explosions? That would have been kind of awesome.

But no. In this case, the word truck is an old-timey way of saying vegetables or produce. Anyway, love them or hate them, house sparrows have become our ever-present companions on this planet. Despite the population declines in recent decades, this species will probably be with us long into the future. We can at least appreciate the house sparrow as a model organism.

With those 7,000 scientific papers and more in the works, I'm sure, this bird has helped us learn a lot about avian biology, and even about some fundamental aspects of just how life works. If you normally ignore or even passionately loathe your neighborhood house sparrows, I have a challenge for you. The next time you see a few of these little birds, take a few minutes to watch their behavior and listen to their vocalizations. You might be surprised at how interesting they can be. Thanks for joining me today for episode 93 of the podcast. Even if it didn't change your opinion of the house sparrow, I hope you learned some new things and can understand these birds a little more deeply. That's certainly true for me

after researching and writing this episode. I've got a few of them in my neighborhood, so it was kind of fun to actually hear them out there chirping and singing, cheer up to me while I was writing. On another topic, you know how I was making jokes about pronunciation earlier, Bactrianus versus Bactrianus and all that? Well, you might know that I care a lot about using proper pronunciations. That can be a challenge sometimes with scientific words, but I do my best. But I have to own up to some pronunciation boo-boos that I made in my last episode, episode 92, which was on deserts.

I mispronounced the names of two deserts. It's not the Namib desert, it's the Namib desert, Namib. And it's the tar or ter desert, not thar. Tar is spelled T-H-A-R, but it's pronounced with just a regular T-Sound. So, Namib Desert and Tar Desert. And then there's the name of those giant iconic cactuses in the Sonoran Desert of North America. A friendly listener from Arizona contacted me and told me that people in Arizona say Sawaro, rather than how I said it, which was saguaro.

The word is spelled S-A-G-U-A-R-O. I've heard it said both ways, but yeah, Sawaro is the best way to say it. That's the correct way. So my bad. If these egregious errors haven't caused you to lose all respect for me, hopefully you'd like me to keep making podcast episodes. Perhaps you'd even like to offer me some support, to give me more opportunities to mess up my pronunciations.

If so, you can become a supporter of the Science of Birds through Patreon. To learn more, just go to patreon.com slash science of birds. Or like I mentioned earlier, there should be a link at the bottom of the show notes in your podcast app. I'm super pleased to welcome my newest awesome supporters. Tracy, Miss Magic Munson, Deborah Sisko, T.J. Wells, Diane Sychman, Julian Perez, and Helena Seever. Siver. Sorry, I'm not sure which. In any case, thank you all very, very much for becoming members of my Patreon community. I'm kind of slow to respond to email sometimes, but if you have

something you'd like to share with me, email is the best way to reach me. Maybe you'd like to correct the way I say a particular word. Or you're a Hollywood movie producer and you want to give me a hundred million dollars to put my sparrows on a plane idea on the big screen. Whatever your message is, you can send it to Ivan at Science of Birds.com. Again, this is episode 93. You can check out the show notes for the episode along with a few photos of house sparrows on the Science of Birds website, Scienceofbirds.com. I'm Ivan Philipson, wishing you a great day. Peace. Thank you.