The Science of Birds - Ask Me Anything About Birds - Aug 2022

Episode Date: September 1, 2022

This episode—which is Number 59—is a bit different. Today, I’m going to be answering questions from my listeners. More specifically, these questions come from my supporters on Patreon. I have several “tiers” or “membership levels” on my Patreon page. Each level comes with perks. One perk for the “Helpful Hornbill” and “Awesome Osprey” tiers is getting to submit questions for episodes like this.So, today, we’ve got a fun grab-bag of questions to ponder.~~ Leave me a review using Podchaser ~~Links of InterestNorthern Mockingbird Wing Flashing Behavior [VIDEO]Link 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 exploration of bird biology for lifelong learners. This episode, which is number 59. is a bit different. Today, I'm going to be answering questions from my listeners. More specifically, these questions come from my supporters on Patreon.

I have several tiers or membership levels on my Patreon page. Each level comes with perks. One perk for the helpful hornbill and awesome Osprey tiers is getting to submit questions for episodes like this. So today, we've got a fun, bag of questions to ponder. I have no shame in admitting that to find the answers for some of these I had to do a little research. As is often the case here on the science of birds, I also learn a lot about birds when I research these episodes. And I love that. I always want to be learning

and expanding my own knowledge. I'm a lifelong learner just like you. All right, let's quit goofing around and have a look at these questions. Judy Hustead has a question that relates to bird evolution and biogeography. Her question is, and I'm paraphrasing a bit, quote, It would be really convenient if the breakup of pangia could explain bird radiations and migration, but the continents were already widely dispersed by, by the time of the Great Extinction, 66 million years ago. What is the timing and pathway by which our North American passerines came to be,

if indeed they all have a New Zealand slash gondwana origin? End quote. That is a fantastic question, Judy. So what we're talking about here is the deep history of birds, from around the time all the other dinosaurs went extinct. Specifically, Judy is asking about birds in the town. taxonomic order Paseroformis. These are the perching birds, right? And this group includes all the songbirds. Where did they come from and how did they get to North America? As Judy alluded to,

ornithologists are pretty confident that passerine birds first evolved on the southern continents. This seems to have happened during the late Cretaceous or within the first few million years after all the large dynos bit the dust. At that time, the world's continents were arranged differently than they are today. Australia was still connected to Antarctica, and Antarctica was connected to South America. These landmasses were fragments of the former supercontinent called Gondwana. Believe it or not, there's a good chance that perching birds first evolved in Antarctica. Yes, Antarctica, of all places. that I like to make fun of for being mostly devoid of avian life today. Even at the time of the big extinction, Antarctica was sitting at the southern end of the planet.

But the climate was very different back then. It was much warmer. The continent was actually covered in dense forests. These might have looked something like the temperate forests we find today in South America. So it's totally reasonable to imagine birds perching and flitting around in the tall trees of Antarctica 66 million years ago. From Antarctica, what we presume is the cradle of passerine evolution, these little buggers spread into Australia. Today, many of the most ancient passerine lineages still live in Australia and New Zealand. Examples include the New Zealand wrens and the lyre birds of Australia. Some passerine birds then moved north out of Australia to colonize Asia and then the rest of the world.

They spread like a virus, like a slow-moving pandemic, an adorable pandemic of happy little birds spreading joy wherever they went. Passerine lineages diversified in Asia and elsewhere in the old world for millions of years. Then came the Miocene Climatic Optimum. This was a groovy time between 18 and 14 million years ago. when the global climate was relatively warm. Ornithologists think that some passerine birds made their way from Asia to North America during the Miocene Climatic Optimum, the M-C-O.

That's how I write it when I'm texting my friends, M-C-O. I'm like, OMG, the weather today totally feels like we're in the M-C-O, L-O-L-L-L-L-O. North America was directly connected to Asia in those days. Siberia and Alaska were linked by the Beringian Land Bridge. This wide swath of land likely provided a path for passerine birds to spread from Asia to North America. The climate was mild, even in those far northern latitudes. There was plenty of temperate forest for wave after wave of passerine birds to invade North America. Yes, they were coming to America.

I'm pretty sure that's what Neil Diamond was singing about. In the last podcast In the last podcast episode, I mentioned that this is the root that the ancestors of Rens probably used when they came to the new world. Evidence suggests that the invasion of the Rens also happened during the MCO, the good old Miocene Climatic Optimum. In the eons that followed, the global climate cooled way down again. It got all frigid up north. And that climatic change may have pushed the perching birds south, deeper into the relatively warm parts of North America.

Then some of these birds kept going, down to central and south America. And that's the story of how the backyards and neighborhood parks of North America came to be positively crawling with passerine birds. The little beasts are just about everywhere you look, whether we like it or not. My first name, Ivan, is pretty unusual here in the U.S. I've met only a few other Ivan's in person over my entire life. So it's pretty crazy that one of my supporters on Patreon is also named Ivan.

Ivan Raymond posed this question Quote Are there any birds that sleep upside down? End quote. Ivan's question might seem a little odd at first, like it came out of left field. But bats sleep upside down, and they too are flying vertebrates.

So it's not unreasonable to wonder if any birds do the same. The short answer is yes. There are birds that sleep upside down. I could just leave it at that and move on to the next question. But what do I look like? Some kind of troll? Well, maybe, but I wouldn't leave you hanging like that. And speaking of hanging, the only birds that routinely sleep upside down

are the hanging parrots of Southeast Asia in India. These are the 14 species belonging to the genus Loriculus. And the genus Louriculus is in the family Citaculidy, a.k.a. The Old World parrots. Hanging parrots are tiny and green, with accents of red, blue, and yellow. They sleep while dangling from small branches in trees. Like other parrots, they have strong feet adapted for gripping. The green color of hanging parrots may camouflage them while they sleep, because they can look sort of like leaves drooping down from a branch tip. So maybe predators have hard time seeing and or reaching a hanging parrot when the bird is asleep, when it's most

vulnerable. The behavior of resting upside down like this to keep from being a midnight snack for a predator may be something parrots in general have been doing for millions of years. It might be a primitive trait. Even though the 14 hanging parrot species are the only ones that sleep upside down, parrots in several other genera do sometimes dangling. from a branch while they're just chilling. They're like literally just hanging out. The true hanging parrots of the genus Luriculus also like to eat upside down. They feed on flowers, nectar, and fruit, such as figs.

Hanging parrots bathe in the rain while, you guessed it, hanging with their heads down. Makes you wonder what else these acrobatic monkey-like birds can do while inverted. Do they mate like that? Not that I know of. But what about when they do their taxes, or play Sudoku, or plot revenge against their enemies? Do they do all that upside down? Who knows? But one other thing they definitely do upside down is empty their bowels.

Hanging parrots often need to poop with their bottom side up. Seems like a real dilemma, doesn't it? But with gravity and all. These tiny parrots don't want to muck up their feathers, so they must have a trick for avoiding that. Indeed, when a hanging parrot feels the urge, it assumes what is called a defecation posture. The bird hangs from one foot, arches its body while raising its tail, and then it shoots. The projectile poop arcs away into the forest, and the tiny parrot keeps its plumage nice and clean. The next question is from Alex L'Otero Vandercam.

She asks, and I'm paraphrasing, quote, Why do Northern Mockingbirds and other members of their family imitate other birds? And what's the theory on how that evolved? End quote. Great question, Alex. Vocal mimicry is something. ornithologists have been puzzled over for a long time. They still don't fully understand

it. There are multiple explanations for why it evolved, multiple hypotheses. The behavior of mimicking sounds is widespread across the avian world. We see it in many types of birds, including parrots, lyrebirds, drongos, starlings, jays, and members of the family mimidy, such as the gray catbird and the Northern Mockingbird. Different bird species might mimic sounds for different reasons. There isn't just one function

of this behavior among birds. Honestly, this subject deserves an entire podcast episode, and it's definitely on my list. But to answer Alex's question today, I'll focus on just the Northern Mockingbird, Mimus Polyglados. This North American songbird

is well known, and, for the most, part, I think, well loved. A male northern mockingbird can have over 200 unique songs in his repertoire. He keeps learning new songs every year of his life. Often, while perched at the top of a tree or bush, the male sings each of his short songs a few times. Then he moves on to the next song. This goes on for some time. Mockingbirds mimic the sounds of other birds, but also of insects, frogs, car alarms, squeaky door hinges, all sorts of stuff.

Mockingbirds even mimic each other. And when they mimic each other, I wonder what happens over time. Is it like making a copy of a copy of a copy so that the quality degrades with each iteration? You know, like the telephone game. Or like back in the 80s and 90s when we'd copy mixtapes. And sometime they'd end up sounding all lo-fi like this. Anyway, what's the deal with all this mocking behavior? Why does our male mockingbird mimic sounds he picks up from his environment?

What function does it serve? Ornithologists seem to be fairly certain that it mostly has to do with mate attraction. Male mockingbirds sing to attract females, just like so many other male songbirds. In the case of mockingbirds, females seem to prefer males with the largest song repertoires. A male mockingbird sort of absorbs the sounds he hears around his territory. As he ages, his repertoire gets larger, larger and therefore more impressive to the ladies. Multiple studies have found evidence that sexual selection is the underlying cause of vocal mimicry in northern mockingbirds. Most of this evidence has to do with the way male mockingbirds change their singing behavior in different contexts.

They vary how much they sing depending on the season, the time of day, whether a female is present, etc. And the repertoire length also changes depending on the situation. So it seems that in this species, a female sizes up the quality of a potential mate based on how well he can, through mimicry, add fresh tracks to his playlist. A male with a large repertoire of accurately copied songs is, perhaps, showing off his superior brain power and commitment to hard work, qualities that should make him a good dad. Just when you thought you were done having to think about northern mockingbirds for the day, I have another listener question about this species.

Adam Knight asks I often see northern mockingbirds land spread their wings several times turn around spread their wings again and then fly away Is this a territorial display Do only males or females do it Is this less or more common than vocal territorial calls?

End quote Cool so like a good naturalist Adam made his own observation of some interesting birdbeard behavior. This sounds to me like a stereotyped behavior in mockingbirds that ornithologists call wing flashing. While walking around or after landing, a mocking bird will often raise both wings in a stiff sort of mechanical motion. The bird repeats this wing flashing however many times. The wing feathers are mostly dark gray, but there's a bright white patch on each wing. These patches are revealed during a wing flash.

Both male and females perform wing flashes. I'll put a link in the show notes to a video of this behavior. But we don't actually know why mockingbirds do this. Ornithologists have a couple ideas. One is that wing flashing spooks insects out of their hiding places. So a mocking bird is walking along, acting like, don't mind me, I'm just a plain little gray bird, nothing to worry about. everybody just go about your business then boo wing flash bugs see those white patches in the wings

and get startled they scramble and the mockingbird goes in for the attack lunchtime another hypothesis about the function of wing flashing is that it spooks predators specifically predators that come nosing around near the mockingbird's nest snakes squirrels crows that sort of thing One bit of evidence that supports the anti-preditor hypothesis is that mockingbirds do more wing flashing during the nesting phase and when the fledgling chicks are still vulnerable. And finally, yes, it's possible that wing flashing has something to do with territoriality, but again, nobody really knows. We'll have to put this one in the Unsolved Bird Mysteries file. For now, anyway. And here's another question about northern mockingbirds.

Just kidding. I love me some mockingbirds, but it's time to move on. This question is from Dan Hammond. It has to do with the time of day that birds sing. Here's Dan's question. Quote, I understand why there is a dawn chorus, but outside of that, I always. have noticed that sometimes during the day there are tons of birds to be seen and heard all

around and then other times you could hear a pin drop and none to be seen. Are there other factors outside of the usual dawn chorus that makes them perk up or perk down over the course of a day or week? End quote. This is another excellent question. Dan said he already understands the dawn chorus. But for the rest of us, let's back up to consider this phenomenon for just a moment. If you're a night owl and you like to sleep in, maybe you've never heard the glorious sound of the dawn chorus. This is where birds of many species start singing loud and proud in the faint light of early morning. This impressive sonic performance can get pretty raucous in some parts of the world, especially in the tropics. It's common for birds to

sing special songs that they use only during the dawn chorus. But once again, scientists don't entirely agree on why birds sing more vigorously in the early morning. The hypothesis that seems most reasonable to me goes like this. Because birds use sight to find their food, it's harder for them to forage effectively in the weak morning light, since they can't see very well in the gloom. If you're awake, but it's still too early to start looking for snacks, what are you going to do? Sure, you could kill some time doom-scrolling the news

or watching silly bird videos on TikTok. But this is actually the perfect time to sing your little heart out. You can attract a mate, mark your territory, or wake up all those lazy humans. So the idea is that it's better for a bird to sing the early morning because singing at that time won't interfere with foraging. A couple of other ideas for why the dawn chorus is a thing are one, the reestablishment of territories and the social order every morning through the power of song.

And two, the possibility that sound transmission is more effective in the morning because atmospheric conditions are relatively calm. But ornithologists aren't entirely sure why the singing activity of birds varies over the course of the day. In northern latitudes like here in the U.S., singing activity decreases as the day gets going and hits a low point at about midday, at least during the spring and summer. That's the time of day when birds are busy searching for food, and it's also when temperatures are highest.

Keeping quiet midday might, therefore, also have to do with energy conservation when it's hot. Deserts give us an extreme example. If you've spent any time in the desert, you know that in the hot middle part of the day it can be almost completely silent. The birds all tuck in for their siestas, waiting to come back out when things cool off in the early evening. So although the jury is still out, it seems like the ebb and flow of birdsong through the day has to do with energy conservation, and how this is affected by light and air temperature. The next question comes from Scott Mon. He wrote, quote,

When I go for a run, I frequently startle birds and send them flying. but when I came up behind a kill deer last week, it just began running down the path. I chased it for probably a good 10 seconds before it finally flew off. That got me thinking, when and why do birds choose to use their legs instead of their wings to get places, including away from potential threats? End quote. This is an interesting question about the kill deer specifically and about the escape behaviors of birds in general.

The kill deer, Caradreus vociferous, is a shore bird in the plover family, Caradreidae. Kill deer spend a lot of time running around on the ground. They can boogie pretty fast on their skinny little legs, but they can also fly perfectly well. These birds nest on the ground, so their eggs and chicks can be vulnerable to both aerial attacks and attacks from ground-based predators. The kill deer has evolved several anti-preditor behaviors, behaviors we call distraction displays. Most famously, a kill deer will sometimes make a plaintive call

while pretending to have a broken wing. This is the injury feigning display. The bird moves away from its nest, luring the predator away from the eggs. The nest and eggs are super-weighed. well camouflaged, so it's easy for the killdeer to draw all the attention to itself. Kill deer have several other distraction displays, including just running quietly away from the nest. Other anti-preditor behaviors involve some flying. The question of whether to run or fly away

from a predator involves trade-offs. Sure, flying is an amazing superpower to have when you're dealing with ravenous cats, foxes, weasels, and other earthbound predators. But taking off with flapping flight also takes a ton of energy. Flight requires a bird to burn way more calories per second than running does. And energy conservation is a big deal for birds, as we talked about in relation to singing versus foraging for food. I imagine each bird species has its own hardwired behavior for quickly to deciding whether to fly or run away from an approaching predator or from a mostly harmless human

runner like Scott. I found one relevant study from 2008 published in the journal Behavior. The researchers did some experiments with wild Eurasian blackbirds in Spain. They tested the birds to see what conditions cause them to fly away from an advancing predator or to just run away. And I love the way the researchers ran their experiments. They went out to several parks in Madrid, Spain. There were wild blackbirds hopping around in the park, minding their own business as they foraged in the grass for worms and insects. Then here comes a human researcher.

They would walk straight toward the blackbird at a speed of one meter per second. As the human closed in, at some point, the blackbird was like, hey buddy uh getting a little close there aren't you seriously dude you're in my personal space no you're just gonna keep walking right at me okay you know what you know what that does it i'm out of here are you happy now you weirdo the black bird either flew away or it ran away in trial after trial with different individual birds the researcher recorded which escape strategy was used as well as the total distance that the that the bird went before stopping. Among other results of this study, it was found that birds who let the quote-unquote predator, the human, get fairly close, those birds usually chose to fly away.

Conversely, the blackbirds who got nervous well before the human got close tended to run away. In experiments where more than one human approached a bird at the same time, the bird was more likely to be like, nope, and choose flying over running. Eurasian blackbirds, and perhaps many other bird species, may choose their escape strategy instinctually to balance how threatened they feel with their need to conserve energy. So when multiple predators are closing in, or when one gets way too close for comfort,

it's time for birds to heed the advice of Gandalf the Grey. Fly, you fools! Fly, you fools. Of course, when Gandalf said that, he meant fly you fools. as in flee. Get out of here. Escape. So in that sense, a bird could fly by flying away or it could fly by running away. You know what I'm saying? Words are fun. Also, can you imagine seeing several people in a park, each of them walking purposefully toward a blackbird on the ground? I picture the scientists wearing white lab coats and holding clipboards. The annoyed bird runs or flies away, then the

researcher scribbles notes earnestly on the clipboard before finding another bird to harass. This is real science, guys, and it is fantastic. Our next question is from Catherine Hannaweiss. Catherine wants to know, quote, How do birds detect and use the Earth's magnetic field for migration? End quote. This is a fascinating topic, one that's complex enough that I could and probably will dedicate an entire podcast episode to it. But let's go ahead and cover the basics here. First off,

what the heck is the Earth's magnetic field? To me, it seems like some kind of magical ethereal force field. But sadly, there's no actual magic involved. The magnetic field is actually the result of liquid iron churning slowly in the planet's core. That iron produces electric currents and these generate the Earth's magnetic field. Somehow. I don't know. I'm not a physicist. The magnetic field extends far out into space. It flows in parallel arcs called field lines, which radiate from and connect to the north and south poles. And all of this is invisible to the human eye, right? The ability to actually sense the planet's magnetic field is called magnetoreception. We know birds have this ability, this superpower, and I'm sure you've heard that. But why would

magnetoreception be useful to a bird? Well, as Catherine implied in her question, this sixth sense is super helpful to a bird when it migrates long distances. The bird can use the Earth's magnetic field to determine direction and maybe even location. Birds can use information from the magnetic field in two ways. First, they can, in a sense, see the field lines. This provides information about direction, east, west, all that jazz. How this works is complex, and scientists are still actively trying to understand it all.

But it seems that there are special protein molecules called Cryptochromes in the eyes of at least some bird species. That's Cryptochrome, not cryptocurrency. Don't get excited. I know all the kids these days are hyped about cryptocurrency. Cryptochrome molecules are sensitive to blue wavelengths of light. This kind of light can excite the cytochrome proteins in a bird's retina. That causes a series of chemical reactions, which end up producing other molecules that can respond directly to the magnetic field. See, I told you. Complex. And I think there's even some wacky quantum mechanics involved here. But the result is that under the right lighting conditions,

a migrating bird can see the magnetic field lines. It can orient its flight path so that it heads either toward or away from the polar region. That's really what the bird's internal compass can do. It tells the bird which direction the poles are. The second way that birds use info from the magnetic field involves an entirely different sensory system. Birds of at least some species have tiny clusters of iron in their upper beaks. These are made of the mineral magnetite. The details of how this works are still uncertain, but it seems that the iron clusters in bird beaks help them sense the local intensity of the Earth's magnetic field. That information may provide the bird with a navigational map of sorts.

So, as far as we know, birds use magneto reception in their eyes for orientation and magneto reception in their beaks for navigation. But there are lots of unknowns. Hopefully, biologists will continue to unravel how these amazing senses work. My long-time supporter, Audra Halleck, didn't have a question, but she was hoping to hear some fun facts about turkeys. Fun facts, it is. I'll give you a couple. So, we're talking about that large, iconic bird of North America, the wild turkey. Meleagris Gallo Pavo. This bird is a member of the family, Fazianity, which includes pheasants, grouse, partridges, and those sorts of critters.

I'll definitely be making a podcast episode about that family at some point. But for now, here's fun fact about turkeys number one. The heads and upper necks of male and female wild turkeys are mostly naked. That's not the fun fact, but I'm getting there. Turkeys have a lot of exposed, wrinkly skin on their faces and necks, punctuated here and there by hair-like bristle feathers. There are also some colorful masses of squishy flesh flopping around. Names for these include wadles and coruncles. Then there's the snood.

S-N-O-O-D. The snood is a type of waddle. It's connected to the turkey's face just above the base of the base of the base of the base of of the upper beak. The snooed droops down from there, falling limply over the side of the bill. It comes in an assortment of fun colors, like icy blue, pink, purple, and white. A short snood might stick out like a fleshy little horn, but this structure can be over six inches long. A turkey's snood length varies, depending on the bird's emotional state, its age, and its sex. Yes, both males and females have these danglers, but those of males are generally longer.

These things are just crazy-looking. Snoods are just another great example of the bizarre features evolution can produce. I'll put a photo of a wild turkey in the show notes on the Science of Birds website. But we're not done. Here's the actual fun fact. Biologists have figured out that a male turkey's snood length is correlated with his overall health. as the old saying goes longer snood healthier dude and females know this females are more likely to choose males with longer snoods so we have sexual selection to thank for snoods honestly i just like the word snood sounds like something from a harry potter novel or from dr seuss it's not every day that you get to repeat the word snood 12 times for an audience like i just like i just like something from a harry potter novel or from dr seuss it's not every day that you get to repeat the word snood 12 times for an audience like i just did. Okay, here's our second fun fact about the wild turkey. Each breeding season,

male turkeys who are closely related to each other form a team to go court females. But usually only one dominant male in the group is lucky enough to breed. Seems like a bum deal for the other males on the team who don't get to breed. But remember that these guys are all related. They're most likely brothers. Siblings share 50% of their genes, on average. So, if your brother gets to breed and make some baby turkeys, a good chunk of your genome is also getting passed down to the next generation. And even if a male doesn't get to breed this time around, maybe he'll be the lucky one next time. Biologists have figured out that this strategy of team or cooperative courtship in turkeys allows subordinate males to pass on more

genes, on average, than they might if they courted females on their own. We turn our attention now to hummingbirds. Everybody loves hummingbirds, right? Dan Vandercam asked this question, quote, Why does the Western U.S. have so many more hummingbird species than the East? End quote. It's true that the eastern states are sadly depopurate when it comes to hummers. There's really just one species that regularly breeds there, the ruby-throated hummingbird. The West, by comparison, is practically infested with hummingbirds. Over here, we have to flail our arms and shoe hummingbirds away like mosquitoes.

Get out of here, you little devils. Go find some flowers. Geez, beat it. There are seven species that breed in the West. Examples include black-chinned, rufous, broad-tailed, and Anna's hummingbirds. But at this point, some of you listening might be wanting to say, But Ivan, that is not correct. Your numbers don't add up.

Because there are at least 14 hummingbird species that read in the U.S. Maybe you should learn how to count, you dummy. While there's no need for insults, you are right. I purposefully left out the additional six or so hummingbird species that we find in the southeastern corner of Arizona. Those birds are primarily Mexican species, but each has a small portion of its breeding range that extends north into Arizona. I left those Southeast Arizona hummers out because they're sort of a special case, an anomaly, if you will. The rest of our hummingbird species, the ruby-throated in the east, and the seven in the west, all belong to one particular lineage. They belong to one branch, one clade of the hummingbird family tree.

Technically, it's a taxonomic subdivision called a tribe. A tribe is the next level down from sub-family. The name of this tribe is Melasuganai. These are the quote-unquote bee hummingbirds. The tribe is named after one of its members, the bee hummingbird of Cuba. You know, the world's smallest bird. The ancestor of the tribe Melasuganai first evolved in South America. Biologists have used genetic information to reconstruct the evolutionary history,

of hummingbirds. Their data and analyses suggest that the ancestor of the bee hummingbird tribe colonized North America about 12 million years ago. Interestingly, the itthmus of Panama didn't exist 12 million years ago. There's that word itthmus. Ah boy, that one always gives me trouble. So there was no land bridge between North and South America at that time. But that didn't stop the little hummers from buzzing their way north over the ocean. After making landfall in the north, those ancestral hummingbirds started to diversify into new species. Several million years later, they had spread up into the western part of the continent, what is today the western U.S. Speciation in the tribe Melasuginae seemed to ramp up starting about five

million years ago. This continued into the ice ages of the Pleistocene epic. The North American hummers were sedentary at first, in other words, non-migratory. But some species, like the Rufus hummingbird, evolved to become strong migrants. In fact, species in the tribe Melasuginae breeding in the U.S. and Canada are the only hummingbirds anywhere that have long-distance seasonal migration. This sort of makes sense, since these tiny birds don't do so well in harsh winter conditions. Now, have I answered Dan's question? No, I sure haven't. Why are there more species in the West? The answer appears to have something to do with mountains and habitat diversity. Western North America is chock full of massive mountain ranges, the Rockies, the Sierra Nevada, the Cascades, and so on.

The east, however, is relatively flat. The biggest range over there is the Appalachians, and those peaks are only about 3,000 feet or 900 meters high, on average. Topographic diversity tends to promote ecological diversity and the formation of new species. All those mountains and valleys created many different habitat types. More species can exist in regions where there are lots of habitats to choose for, There are more niches to fill. The Rocky Mountains have been around for about 80 million years,

but the Sierra Nevada in the far west began to rise up only about 10 million years ago. I imagine that with this increase in topographical relief came a corresponding increase in flowering plant diversity. Hummingbirds depend on flowers, so the equation has to include them as well. and many of these plants have co-evolved with hummers since they rely on the birds for pollination. Could it be that the uplift of the sierras and other mountains in North America, including Mexico, helped promote species diversity in hummingbirds?

The answer is yes. The connections between mountains, flowering plants, hummingbird evolution and migration is discussed in a great paper from 2017, published in the journal, BMC, Ecology and Evolution. The paper's title is The Conquering of North America, dated phylogenetic and biogeographic inference of migratory behavior in bee hummingbirds.

I'll put a link to it in the show notes on the Science of Birds website. Anyway, fun stuff to think about. If you want to learn more about hummingbirds, you can listen to episode eight of the podcast, which is all about the hummingbird family, trochility. But enough about birds, let's talk about me. The last question comes from Cameron Behe.

She actually asked a couple questions about me and my relationship with birds. Cameron wrote, quote, What are your favorite birds to watch? What bird behaviors do you find most fascinating? End quote. Oh man, that's tough. I'm fascinated by so many different kinds of birds. I truly love them all, seriously, even house sparrows and penguins. But as I think I've admitted here before, I'm a sucker for colorful birds. I guess I'd have to say that some of my favorite birds to watch are

woodpeckers, parrots, shorebirds, and neotropical tanagers in the family Thraupidae. The diversity of colors and plumage patterns in those tanagers is mind-blowing to me. Most of them are just gorgeous. As for bird behaviors, I think it's always fascinating to watch birds as they forage. I love to see them using their bills in just the way they're adapted for. So I enjoy watching foraging behaviors and birds with unique bills like flamingos, skimmers, curlews, and crossbills. I think courtship and territorial behaviors during the breeding season are also super cool to observe. One example that comes to mind is watching a male dark-eyed junko in my backyard as he flies from perch to perch singing his tiny heart out to maintain his territory. You know, thinking about all this

really makes me want to run out the door with my binoculars and go find some birds already. Who's with me. Well, that concludes this Ask Me Anything episode. I hope you enjoyed it and that you learned a few things. Thanks so much to all my supporters on Patreon, including those who submitted questions for this episode. You guys came up with some really good ones. I want to welcome my newest patrons, Robin Isidora, Isidora, Laura, Mick McSee, Beth Ann Bacill, Wayne Turner, and Holly Hefele.

Sorry if I bungled any of your names, but I deeply appreciate your help in making the Science of Birds possible, so thank you. If you want to know how you can become a supporter of this podcast, you can check out my Patreon page at patreon. At patreon.com slash science of birds. You're also welcome to send me an email if you have a comment about the show. or you want to tell me about your favorite birds to watch. Or maybe you want to trick me into joining a cryptocurrency pyramid scheme. Whatever the case, you can send your email to Ivan at Scienceofbirds.com. You can check out the show notes for this episode, which is number 59, on the Science of Birds website, Scienceofbirds.com.

This is Ivan Philipson, wishing you a wonderful day. Cheers. Thank you.