The Science of Birds - Mockingbirds and Thrashers

Episode Date: October 31, 2025

👕 Bird Merch —  Get yourself some bird shirts!~~~This is Episode 124. Host Ivan Phillipsen takes you on a tour of Mimidae—the New World family that includes mockingbirds, thrashers, catbirds, and tremblers. He describes the key features of these songbirds and what sets them apart.Ivan explores the sounds that make this family famous: rich, extended songs, dazzling vocal control, and—for many species—impressive mimicry.You'll also learn about mimid diversity and evolution, from North American backyards to Caribbean islands and desert specialists of the Southwest, plus a look at conservation challenges facing some species.Links of InterestNorthern Mockingbird Wing Flashing [VIDEO]Catbird singing [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 is episode 124. It's all about birds in the family, Mimidi. These are the mockingbirds, thrashers, catbirds, and tremblers. There are 35 species overall.

This family is restricted to the New World, to North, Central, and South America. Some of these songbirds are familiar backyard visitors. In North America, these include the northern mockingbird, brown, thrasher, and gray catbird. The tropical mockingbird and chalk-browed mockingbird are familiar urban and suburban birds in South America. The northern mockingbird is so well-loved and well-known that it is the official state bird of Arkansas, Florida, Mississippi, Tennessee, and Texas. So I'll have to dedicate an entire podcast episode to the northern mockingbird at some point. But for today, we're doing an overview of all the mimids. all the species belonging to the family Mimidi.

To choose the topic of this episode, I sent out a poll to the members of my Patreon community. They got to vote on it. The choices were Mimidi or sternity. Sternadie is the family of the starlings. Now these are both wonderful and fascinating groups of birds, and both are known for their spectacular singing abilities. But in this head-to-head showdown,

in the pole, the mimids beat out, the sternids, 54% to 46%. So let's do it. Let's get to know the mockingbirds, thrashers, catbirds, and tremblers. We'll start with what these birds look and sound like. They're medium-sized songbirds, with a fairly typical songbird body shape,

sort of thrush-like overall. Many mimid species, especially the mocking birds, have relatively long, graduated tails. And by graduated, I mean the outer tail feathers are progressively shorter than the central tail feathers, so that the tail appears to taper or step down towards the sides. The wings of birds in this family are somewhat rounded, and their legs tend to be long and strong.

Such legs are great for birds that spend a lot of time on the ground, running or hopping around in the undergrowth in search of food. How about the bill, the beak? Mimids tend to have slender, longish bills. Many of them have bills that curve downward, or we could say their bills are decurved. This is especially true for the thrashers. The species with the longest, most deeply curved,

curved bills are the curve-billed thrasher, California thrasher, Lacance thrasher, and the Chrysall Thrasher. You know, when I was writing the script for this episode, my spell checker at first would change the name of the Cristle Thrasher. It changed Crisill, C-R-I-S-S-A-L, to crystal. I was super annoyed. No, I didn't mean Crystal, you stupid spell checker. But then I updated my personal dictionary in Google Docs to include Cristle and that fix. it. But Crystal Thrasher sounds kind of cool, doesn't it? Crystal Thrasher. Like it could be someone's name. Maybe the front woman in a heavy metal band or something. I don't know. Or maybe another name for a hypothetical daughter of mine. Crystal Thrasher Philipson. And if you're wondering

about this word, chrysal, this comes from the zoological Latin word chrissum, C-R-I-S-U-M. The chrissom is the feathered area around a bird's vent, so the area surrounding the cloaca and the associated feathers, including the undertale coverts. This is all under the base of the tail. The plumage of the chrysal thrasher is pale gray all over except for the vent area, the chrissom, which stands out as a chestnut or rufous color, sort of reddish-brown. So the word chrysal is an adjective, and it means related to. to the chrysum.

Anyway, back to the family mimidi in general. I should also mention that the brown trembler synchloserthia ruficata and the gray trembler, synchloserthia gutterales, both have an exceptionally long robust bill, though not quite

as curved as those of most thrashers. There are exceptions to this theme of long, decurved beaks among the thrashers. The sage thrasher, for example, has a relatively short, straight bill. And most mocking birds also have shorter, less curvy beaks. I should also point out that juvenile birds in this family tend to

begin their lives with shorter, straighter bills compared to the adults. The bill then gets longer and more curvy as the bird matures. Bill color among mimids is typically black, gray, or a dusky brown. In terms of the overall size of these birds, Mimids range from 7.5 to 13 inches, or 19 to 33 centimeters from beak to tail. The smallest species is the black catbird, melanoptola glabroostris. Several thrashers species are contenders for being the largest mimid, but the California thrasher, toxostoma redavivum, wins at about 13 inches or 33 centimeters long. Plumage patterns among the birds in this family mostly confirmed,

form to a sort of thrush pattern, brown or gray on the top, pale with spots or streaks underneath. So the overall impression of coloration in these birds is gray or brown with some black and white accents. The northern mockingbird, for example, has gray to brown upper parts and a pale belly. It has bold white wing patches and a black and white tail. Those wing patches and that long black and white tail are conspicuous when the mockingbird flies. The iris color of an adult northern mockingbird is light greenish yellow or yellow. As another example, we have the brown thrasher. This bird has bright reddish-brown upper parts and whitish underparts with thin dark streaks.

And the eyes are, again, a vibrant yellow. But not all mimids are brown or gray. There are a few outliers. The black catbird, I mentioned, the smallest mimid of all, is one of them. It is indeed black all over, but in the right lighting, those black feathers shine with purple and blue iridescence. Also, one source pointed out that the black catbird is, quote, rather cute, with a gentle aspect and shiny inquiring eyes, end quote.

And yeah, it really is a cute little bugger. Just look at some photos of the black catbird and, you know, you can witness the cuteness yourself. The blue mockingbird and the blue and white mockingbird are the most unusual species in terms of plumage. These are the only two species in the genus melanotus. The blue mockingbird, Melanotus, Cyrillessons, is deep blue all over. It has a black mask across the sides of the head. The blue and white mockingbird, Melanotus, hypolucous, is pretty similar, but its throat, breast, and belly are white. And that specific epithet, Hypo-Lucus, means white underneath.

And the eyes of both species have blood-red irises. Another outlier, I should mention, is the gray catbird, Dumatella Carolinensis. Its plumage is a smooth, medium gray overall, with a black cap. It also has rusty red undertale coverts, as in the chrissum, right? I think that's our ornithology word of the day, chrissom. Hey, maybe we can celebrate it every year as a holiday. We shall call it chrysumus. Merry chrysumus, everybody.

Males and females in the family mimidy tend to be quite similar, so there isn't much dimorphism or dichromatism. Now I have a few notes about the general behavior of birds in this family. Some of these birds are quite bold. For example, many mockingbirds in the genus Mimus, like the northern mockingbird, are real swashbuckling rascals that like to perch out in the open for all to see and hear. That's one reason mockingbirds are familiar to so many people. But other species are much more skulky in their behavior.

They keep hidden in the leafy undergrowth, rarely venturing out into the open. This is true for many thrashers. The blue mockingbird is also famously skulky. It's a beautiful, charismatic bird, but it's much more often heard than seen. With its black mask and cool blue costume, it keeps to the shadows like some kind of vigilante superhero, maybe dealing out street justice to avian criminals like brood parasites. When I was looking for photos of blue mockingbirds, very few of them showed the bird out in the open, perched in good lighting.

Most of the photos are grainy and the bird looks like a blurry blackish-blue blob. And I too have tried, without much luck, to get decent photos of a blue mockingbird. One interesting behavior seen in a number of mimid species is called wing flashing. This is the rapid opening or spreading of the wings. The movement style varies,

ranging from a jerky motion to a more rapid, smooth spreading. Wing flashing is a broad category of behavior that includes diverse movements or postures. For example, there's wing lifting, where the wings are lifted vertically above the body. And there's wing fanning, where the wings are held out horizontally in a sort of umbrella shape. This is a behavior commonly seen in the Northern Mockingbird. In its wing flash display, a mockingbird suddenly opens its wings revealing those big white patches. So why do northern mockingbirds do this? Why do any mimids make these wing movements? One hypothesis is that it might be to spook bugs so they're easier to catch. The sudden movement

with those bright white patches could, hypothetically, cause a small insect to flinch, to reveal itself to a hungry bird. Seems like a reasonable idea. But there is some evidence that shows that this doesn't really work all that well. So, the adaptive function of wing flashing in mimids remains highly debated among ornithologists. There's no single universally accepted hypothesis. Besides spooking insect prey, another possible explanation for this behavior could be predator defense, because some mimids flash their wings at snakes, lizards, and even pesky humans. Whatever its true function, wing flashing of one sort or another is seen in at least seven species of mockingbirds, as well as the brown thrasher and the gray catbird. Okay, it's time to talk about the vocal behaviors of birds in the family mimidy.

They are, of course, famous for their amazing singing abilities. Now, first off, many of them are skilled mimics. When Carl Linnaeus assigned a scientific name to the northern mockingbird back in the 1700s, he settled on a name that highlights this bird's ability to impersonate other species. Mimus polyglotos. The genus, Mimus, M-I-M-U-S, is Latin for Mimic, and that's where the family also gets its name. Mimus. You know, like a mime, an obnoxious person who paints their face white and wears a beret and white gloves and a stripy shirt. But of course, human mimes like that are silent, Our mimid birds are anything but silent.

The second part of the specific epithet of the northern mockingbird is polyglotos. And that's from ancient Greek, and it means many tongues, or many languages. In English we have the word polyglot, right? That's what we call a person who speaks multiple languages, a polyglot. Not to be confused with polywog. A polywog is what we call someone who has more than one wog. and also a larval frog or toad. So yes, mockingbirds can reproduce sounds.

Given their name, they must mock, right? They tease and make fun of other birds. So a northern cardinal is talking to its friend, and it says, It's cold out here today, don't you think? And a mocking bird swoops over and rudely interrupts. The mockingbird says, It's cold out here today. That's what you sound like.

Wah, I'm a little baby cardinal, and I'm so chilly. I wish my mommy would wrap me in a blanket and feed me hot soup so that I don't freeze to death because I'm cold, and I'm also stupid. Well, thankfully, that's probably not what's going on. We don't need to condemn mockingbirds as being avian bullies. As far as we know, they aren't actually mocking anybody. So maybe a better name would be mimic birds. birds, or copycat birds, something like that. But some species in this family don't mimic at all,

or they do so only rarely. For example, that's the case for the Brown Thrasher, Bendire's Thrasher, and the tropical mockingbird. These birds have complex songs, but they don't necessarily mimic, at least not very often. So what is the underlying anatomy that gives mimids their vocal superpowers. Well, it surely has a lot to do with how their brains are wired. But that aside, in terms of what makes the sounds themselves, there's the organ called the syrinx, S-Y-R-I-N-X. I've talked about this in other episodes of the podcast. The syrinx is a bird's voice box. It sits deep in the chest where the windpipe splits into the lungs. Unlike our single larynx, almost all osine songbirds, so over 4,000 species, have a bilaterally symmetrical syrinx with two sides.

Each side can, in principle, produce its own sound. Mimids like the Northern Mockingbird, Brown Thrasher, and Gray Catbird can produce multiple frequencies simultaneously by using the two sides of the syrinx together. They alternate rapidly between sides of the syrinx, or sometimes use both simultaneously, producing complex, overlapping tones. Imagine if humans could do this. If we could make two different vocalizations at the same time, it would be so cool. We could harmonize with ourselves while singing, or we could say two things at once, sort of like this.

If you like black licorice, you are not my friend. It's not that mimids are unusual in having a sense. syrinx with two sides, but they are unusual in having extremely refined bilateral control of their syrinxes. In other words, the basic anatomy isn't unique, but their degree of coordination between the two sides of the syrinx, and their vocal precision is exceptional among songbirds. This ability is confined to specific vocal frequencies, between 750 and 7,000 hertz. That's the range for the northern mockingbird anyway. The left side of its syrinx produces lower frequency sounds, ranging approximately from .75 to 3 kHz, while the right side produces higher frequencies, ranging from

1.6 to 7 kHz. Mockingbirds incorporate sounds from within that frequency range into their famous mocking or mimicking songs. So one time when a northern mocking bird spooked me in the middle of the night by mimicking the beeping sound of my car's alarm system being turned off. I guess that beep was in the frequency range between 750 and 7,000 hertz. The songs of some mimids can go on continuously for a long time, like 10 to 20 minutes. And there can be hundreds of distinct phrases in the song, and those phrases may not be repeated. And as many of us have noticed, Northern Mockingbirds often sing long and to the night, especially during the full moon. These nocturnal crooners tend to be males that have

yet to find a mate. Northern mockingbirds and probably many other mimicking mimids are what we call open-ended learners. They can keep learning new songs as adults and for their entire lives. A typical male northern mockingbird can learn 200 or so songs over his lifetime. Mimics incorporate not just the sounds of car alarms and other bird species. They sometimes add phrases from the sounds of other animals, like frogs. For example, northern mockingbirds have been documented mimicking at least 12 frog species, and researchers have figured out that those frogs make vocalizations that fall within the vocal frequency range used by mockingbirds. All right, well, let's actually listen to a northern mockingbird singing. I'll play a full minute of this song. Notice the

amazing variety of the individual phrases. PAMPAPAp BAS. POSI-BOR. BASK-BURGY-BURGY-BORI-BORI-BORI-BORI-BORI-BORI-BORI-BIN-BIN-BIN-BIN. FI-BIN-BIN-BIN-B-BIN. The tropical mockingbird, my miss Gilvis, is the closest relative of the northern mockingbird. But interestingly, the tropical mockingbird rarely mimics other birds or other sounds.

Here's a short song made by a tropical mockingbird in Columbia. Next up we have a chalk-browed mockingbird, Mimus Saturninus. This species does mimic other sounds. This one was recorded in Argentina. So that was a chalk-browed mockingbird. And you know, if you want to impress your friends with your bird lingo, make sure you refer to the tropical mocking bird and chalk-browed-mocking bird

as the trop-mock and the chalk-mock. I mean, I'm not sure anyone has ever used those names, but what if? It would be cool. We can start the trend right here, right now. Oh, and we can call the Chilean mockingbird the chillmock. Tropmock, chalkmock, and chillmock. Okay, let's listen to some more bird noises. This next one is from a blue mocking bird.

Remember that this species is not in the genus Mimus. The blue mocking bird is in the genus melanotus. Again, that was a blue mocking bird, and it was recorded in Oaxaca, Mexico. Next we have the brown thrasher, Toxistoma Rufam. This species is famous for its amazing vocal talent. A brown thrasher can have overworked. 1,000 song types or phrases, or up to 2,000 in some cases. That means this species has the largest repertoire of any North American bird, and one of the largest in the world that we know of.

Brown Thrashers are able to mimic other birds, but they do so only occasionally. This bird's song can go on seemingly forever. I suppose we could spend the next hour of the episode just listening to a Brown Thrasher singing non-stop. As fun as that might be, we all have busy lives, so I'll play only about a minute of a song for you. This one was recorded in Minnesota. As you listen, notice that each short phrase is separated by a pause, and each pause is between half a second and one second long. I don't know what I'm going to be. I'm going to be.

I'm going to be. I'm going to be. I'm going to be. I don't know. I'm going to bea. Psyp. I'ma. I'maqa-kha-kha-khae.

I'ma-ha-ha-haean-a-haean-a-haean-a-haean-a-eo-a-eo-a-eo-a-eo-a-eo-a-eo-a-a-eo-a-a-eo-a-eo-a-eeeo. Next we have another thrasher species to listen to. This one is Toxtoma Redavivum, the California Thrasher. That again was the California thresher. Then we have the gray catbird. It gets its name from its distinctive mewing call. It sounds sort of like a little kitty cat. In the following recording, which was made on an island in Nova Scotia, Canada, you'll hear the cat-like call of the gray catbird.

You can also hear ocean waves in the recording and like a foghorn or something in the distance. But you'll also hear what sounds like apes screaming in the background. Primates are uncommon in Canada, so I think those screaming creatures must be common ravens. So that was the sheep So that was the call of the gray cat bird. Now let's listen to its song. This is a rambling series of sing.

phrases. This one was recorded in Minnesota. You might hear some black-capped chickadees singing in the background. Gray catbirds have complex songs, like their cousins, the mockingbirds and thrashers, with hundreds of unique phrases. Interestingly, ornithologists have discovered that young gray catbirds don't need to learn their songs from an adult. Male catbirds raised in captivity, without ever hearing another catbird, will still produce a rich repertoire of typical gray catbird phrases. So, at least in that species, song development is largely innate and does not depend on imitation. I'll put a a link in the show notes to a nice little video about the vocal mimicry abilities of a gray

catbird. Okay, I've got one more recording to play for you. This one is the gray trembleer, synchlosurthia Gutarellus. It was recorded on the Caribbean island of St. Lucia. There are two trembler species, both living in the Caribbean. They get their name from the behavior of trembling or sort of shivering while they sing. So here's the gray trembler. One last note about vocalizations in the family mimidee. Some female mimids also sing. It's not just the males.

For example, in California Thrashers, the female will counter sing with a male. So they trade off singing back and forth. Northern Mockingbird females also sing, but they sing more softly and quietly than the males. If you'd like to learn more about female bird song, check out episode 50 of the podcast, which was all about that. Now let's talk about the systematics of the family Mimidi. Systematics, in very simple terms, is the science of figuring out how all living things are connected through their evolution.

We visualize those relationships using evolutionary trees, or we can use the more technical terms, phylogenetic trees or phylogenies. These trees have two key features, the branching order, which shows how different groups are related, and the branch length, which tells us how much evolution has happened along that branch. The longer the branch, the more evolutionary time. The family mimidi is one branch on the overall avian tree of life, the phylogeny that includes all birds. The next branch over from that of mimidi is the family sternity. Maybe you remember from the beginning of the episode that sternity is the family of the starlings. So starlings are the birds most closely related to the mockingbirds, thrashers, catbirds, and tremblers. The impressive vocal talents, including mimicry, were most likely already present in the ancestral

bird that gave rise to the family's mimidy and sternity. These families belong to a superfamily called Musca Capoidia. There are five other families in that superfamily, including those of the thrushes and dippers. And actually mockingbirds used to be included in the thrush family, once upon a time, because, as I mentioned, they look sort of like thrushes. So there's this big branch named Musca Capoidia, and it splits into seven smaller branches, each of which represents a single family. And one of those is mimidi.

The common ancestor of the group that includes mimidi and sternity probably originated in East Asia in the early Miocene epic, so roughly 25 to 20 million years ago. The highest species diversity today, for mimids, is in western North America. And given the close relationship with sternity, a strictly old world family, it seems the ancestral mimid probably came to America from Asia during the mid-Myocene via the Beringia land bridge. That's the land that used to connect Siberia and Alaska. You know, the same bridge humans in Asia used when they colonized the Americas for the first time. Now, as a total side note, you might have heard that there are some other birds out there in the world that we call catbirds.

There are 10 catbird species in Australia and on the island of New Guinea. But those are not closely related to the catbirds in the New World. Those Australasian catbirds belong to the family Telenorinkedy, which is the Bowerbird family. But those catbirds got that name because they too make some cat-like note. There's also a species called the Abyssinian catbird. That one lives in Ethiopia and it's in the old world warbler family, Silveidi. This species is not closely related to the catbirds in the new world or to the Australasian catbirds. All right, just wanted to make sure I clarified that. So still on the topic of systematics, we can zoom in further to look for branches within the family

Mimidi. Multiple studies using genetic data from DNA have revealed that the species in this family are divided into two major branches. In the terminology of systematics, we could also call these branches clades, C-L-A-D-E-S. The first clade or branch includes all of the mimus mockingbirds and the continental thrashers, which belong to the genera toxostoma and oeoscopies. That all adds up to 25 species for this branch. The second branch includes the 10 remaining species, so the blue mockingbirds, catbirds, Caribbean thrashers, and the tremblers. In many other bird families, branches like these two would be formally designated as sub-families. You've heard me talk about sub-families many times in other episodes. Well, ornithologists have not assigned official names

to the two branches, these two distinct evolutionary lineages within Memadie. Who knows? Maybe someday. Now I want to highlight a couple of species. A moment ago I mentioned the genus Oreoscopi's. It contains just one species, the sage thrasher, Oreoscopi's Montanus. Montanus, as in Mountain. The original name for this species was actually Mountain Mockingbird.

That isn't super surprising because the sage thursday. thrasher looks like an intermediate between birds in the genera mimus, the mockingbirds, and toxostoma, the typical thrashers. And remember I said that the sage thrasher has a short, straight bill, much more like a mockingbirds bill than your typical thrasher. And the sage thrasher is also the smallest of the thrashers, for what it's worth. It seems this bird is indeed a not-so-missing link between these two groups. The evolutionary tree, or phylogel genetic structure for the three groups proceeds sequentially in terms of their evolutionary history. First, the toxostoma lineage branched off and it diversified into the other thrashers.

Then the sage thrasher lineage separated before the major diversification of the mimus mockingbirds. So that's kind of cool. The sage thrasher, if you ever get to see one, is again sort of a missing link, even though it's not actually missing. The other bird I want to highlight for the moment is the black catbird. Melanoptola, glabriroastrous. That's a tough one. Glabriroastrous. It too belongs in a genus of one. Remember that the black catbird is the smallest member of the family and it's the cute one with a gentle aspect and shiny inquiring eyes. It lives on the Yucatan Peninsula in Mexico and Central America. The question is, should we actually call the black catbird, a catbird. Sure, it behaves sort of like its northern cousin, the gray catbird,

but the black catbird doesn't make cat noises, and it doesn't mimic and it doesn't have rictal bristles at the base of its bill, the way the gray catbird does. Rictal bristles, you may recall, are stiff hair-like feathers around the margins of the bill where the bill meets the face. So, if it's not really a catbird, what common name should we use for melanitis? Optala glabryroastrus. Maybe black cute bird? No, shiny-eyed gentle bird? I don't know. I'll leave it to you guys to decide. Let me know what you come up with. Okay, so to review, we've got 35 mimid species, and they're divided into 10 genera. Those genera are grouped into those two major branches, or clades. 28 species occur in North America, and 14 in Central and South

America, with some overlap between those regions. The most common species in North America are the northern mockingbird, gray cat bird, and brown thrasher. In South America, the most common species are the chalk mock and the chill mock. You know, the chalk-browed and Chilean mockingbirds? One of the interesting patterns in this family is what's going on with toxostoma thrashers in the arid and semi-arid parts of the southwestern U.S. There are six thrashers species in this region.

The California Thrasher, Curve Build Thrasher, Crissel Thrasher, Bendire's Thrashor, Gray Thrashor, and LaConce Thrasher. This group of most excellent birds is called the Southwestern Thrashor Radiation. Radiation, as in a group of species that all evolved from a single common ancestor to fill different niches over a relatively short amount of evolutionary time. and also southwestern thrasher radiation would be a sick band name, don't you think? And speaking of radiation, another fantastic and scientifically significant example comes from the Galapagos Islands. No, I'm not talking about Darwin's Finches. I'm talking about the four closely related mockingbird species there in the genus Mimus. When Charles Darwin explored the Galapagos in 1835, he noticed that there were different

mockingbird species on different islands. This observation was one piece of the puzzle that Darwin used to develop his theory of evolution by natural selection. So it's not an exaggeration to say that mockingbirds played an important role in helping us humans understand evolution. The philosopher Daniel Dennett once said, quote, if I were to give an award for the single best idea anyone has ever had, I'd give it to Darwin. In a single stroke, the idea of evolution by natural selection unifies the realm of life, meaning and purpose with the realm of space and time, cause and effect, mechanism, and physical law. End quote. Wow, the single best idea ever. Thanks, mockingbirds! The radiation of mockingbird species in the Galapagos traces back to a single common ancestor. And that ancestor came

from a lineage most similar to the Bahama Mockingbird, way over in the Caribbean. That's what the genetic data tell us, even though it's a bit counterintuitive. Looking at a map, you'd see that the mainland of Western South America is much closer to the Galapagos than the Bahamas. But the genetic data tell us what they tell us, right? Nature is sometimes counterintuitive. Interestingly, the four mockingbird species in the Galapagos are also special because they're relatively fearless, they live in flocks and breed cooperatively, and they're extremely opportunistic in terms of what they eat. And we'll talk about that in a moment. But first let's

consider the distribution of this family. As I mentioned earlier, birds in the Mimidi family are restricted to the New World, North, Central, and South America. And the highest diversity is in Western North America. The islands of the Caribbean are home to some of the the, I suppose we could say, weirder species. Maybe not weird enough to warrant a weirdo alert, sadly. But these somewhat weird Caribbean birds are the thrashers and tremblers belonging to the genera Ramphosynclis, Alenia, Margarops, and Syncloserthia. Some of these Caribbean birds occupy tiny ranges.

For example, the St. Lucia Thrasher, Ramphosynclis, Saint-ilus, Sainctilusian, lives on just one island. And it lives in only two small habitat patches on that island. In terms of migration, most mimids are permanent residents. They don't migrate. The gray catbird, however, is a full-blown neotropical migrant. It leaves its summer range in North America to spend the winter in places like Florida, the Caribbean, eastern Mexico, and Central America. Other mimid species are partially migratory. For example, birds in the northern populations of Bendyers and sage thrasher often migrate south, but the southern populations in those species remain in place year-round. Some of these birds appear to be facultative migrants. They travel to different places depending, not so much on the season,

but on where berries and fruit crops are available. Now what about habitats? Mimids in general are common in open habitats. But habitat requirements vary widely among species, from forest undergrowth to scrub, high altitude grasslands and deserts, but dense cover is essential for most species, especially thrashers. Some species, like the northern mockingbird, are habitat generalists. Others are specialists. Examples of specialist species include the California thrasher, which requires chaparral habitat, and the sage thrasher, that is a sagebrush obligate. And Lacance thrasher is a specialist that requires hot desert habitats with little vegetation and lots of sand. The organization's Bird Life International and the International Union for the Conservation of Nature,

working together have placed about one-third of the 25 mimid species on the red list. Two of those species are in the critically endangered category, the sacoral mockingbird and the Kazumel Thrasher, each lives on just one small island. The Cosumel Thrasher, Toxistoma Gutatum, looks a lot like the brown thrasher. Or maybe I should say it looked like the brown thrasher, past tense, because, sadly, the Cozumel Thrasher is quite possibly extinct. It suffered major population declines after Hurricane Gilbert smashed into the island of Cosomel in 1988 and when Hurricane Roxanne hit in 1995.

On top of all that, introduced species, such as predatory boa constrictors, have probably had a serious negative effect on the Casamel Thrasher. As far as I know, no one has seen this species since about 2004. Mimids in general are threatened by habitat loss. Island species, like those in the Caribbean and elsewhere, are particularly vulnerable. And I have a hard time with particularly. That's a tongue twister for me. For example, the Socorro mockingbird population was greatly reduced after sheep and cats were introduced

to Socorro Island. Sheep destroy habitat and cats eat the birds. There are only about 300 to 500 Socoral mockingbirds left. But the Mexican Navy has been removing sheep from the island and replanting native shrubs. So restoring habitat. Thanks to those efforts, it seems the mockingbird population is starting to recover. It's time to talk about what birds in this family eat. Their overall diet is quite varied. These omnivorous birds eat all sorts of things, including insects and other arthropods, small vertebrates like lizards, snakes, and frogs, and also eggs, nuts, seeds, and fruit.

North American species eat a lot of small fruits, especially in the fall and winter months. Maybe up to half of their diet in that season is berries. This is the case for the gray catbird and the northern mockingbird. Even though many mimids tend to feed on the ground, when they're feeding on berries, they'll hop up into the branches of shrubs to get access to the fruit. As I mentioned, Galapagos mockingbirds are generalists when it comes to their diet. And that makes sense, given that they live on arid, isolated islands. It's better not to be too picky when resources are limited.

Well, at least three of the four mockingbird species in the Galapagos happily pluck ticks off the skin of marine iguanas and land iguanas. That's interesting because after starlings, the next most closely related family to mimidi is buffagody, the oxpeckers. There are two oxpecker species, both in sub-Saharan Africa, and their diet is exclusively composed of things they get from the skin of large mammals. Ticks, dead skin, and even blood. And speaking of blood, believe it or not, one of those Galapagos mockingbird species

loves to slurp up the red stuff, like a little feathery vampire. I'm talking about the Española mockingbird, Mimus McDonald's. It's the largest and most fearless of the four species in the archipelago. ago. I've experienced their cheeky behavior firsthand. When you step on shore on Española Island, look out because here come the mockingbirds. They run across the beach right up to your feet. They look up at you expectantly, like you owe them some kind of tribute for setting foot on their island. Greetings, human! You will give me snacks now. It is the law! Brazen Española mockingbirds will land on your head too and on your backpack. They'll steal a drink from your open water bottle.

And you better hope you don't have any wounds on your bare legs, because these little buggers will peck at your flesh to get some sweet, sweet blood. Seriously, it's pretty wild. And you know, if Espanola mockingbirds were to keep evolving in this sanguinivorous direction, becoming vampiric pack hunters, maybe they would be like flying piranhas. That would be Spooky, right? Imagine you're a tourist and you step off the boat onto the beach, thinking you're going to have a lovely day of photographing sea lions and nesting albatrosses, but suddenly a dark cloud passes across the sun. It descends on you in a flurry of little wings and pointy beaks. You have the misfortune of being targeted by a ravenous flock of Espanola mockingbirds.

After only a few minutes, the satiated flock moves on, leaving on the beach only your camera, your backpack, and your skeleton. Speculative evolution is fun, isn't it? And yeah, I know, that's kind of morbid. But hey, I'm making this episode during the Halloween season, so it seems like it's okay. For real, though, as Spoddy, Mollah Mockingbirds routinely drink blood from wounds on sea lions, iguanas, and nestling birds like

blue-footed boobies. Okay, let's shift gears and talk about thrashers. How did they get that super cool name? Well, it has to do with the way they forage. The long curved bills and associated skull structures in many thrashers are adaptations for their habit of digging and probing for prey in leaf litter. Thrasher's often pick up leaves and twigs and toss them out of the way, so they thrash around in the leaves. Their curved bills are strong, effective tools for this activity. For example, Lacance thrasher has been known to flip items as heavy as one and a half times its own body weight. That would be like me picking up and throwing a boulder that weighs 250 pounds, 113 kilograms. Picking it up and throwing it with my teeth. Thrasher's also

search for food by digging holes in the ground with their bills, up to several inches deep. And all that activity, thrashing and throwing dirt and sand, that can be noisy and conspicuous. So that's one way that we birders can find thrashers. For example, I remember when I found my very first California thresher. I heard it first as it was scrabbling around, thrashing, if you will, in a pile of brown leaves underneath some cottonwood and mesquite trees. Most species in the family mimidie are socially monogamous when it comes to breeding, a male and a female pair up to raise a brood. Some species, like the northern mockingbird might stick together across multiple breeding seasons, or even for life.

Some pairs have been documented staying together for at least six to eight years. The St. Lucia Thrasher and Tropical Mockingbird, as well as the four Mockingbird species in the Galapagos, are different. They are cooperative breeders. For example, in the tropical mockingbird, the Tropmock, a breeding pair is joined by up to five other individuals in their territory. The latter birds are the young from previous broods. They help in feeding their younger siblings and in defending the territory. Most species in this family engage in courtship displays. Courtship often includes the exchange of nesting material. Northern mockingbirds use several courtship displays, such as an acrobatic flight where the male chases the female around.

Male northern mockingbirds also make displays that show off those bright white wing pads. matches. Most mimids are highly territorial birds. They aggressively defend their nests. Mockingbirds and brown thrashers are known to attack dogs, cats, and humans. They hit people sometimes so hard with their bills that they draw blood. These birds can be territorial in the non-breeding season too. Mockingbirds will often drive other birds away from valuable food sources, like dogwoods or other fruit-bearing trees. Regarding the territorial behavior of the St. Lucia Thrasher, here's a great quote from a paper published in 1872.

The St. Lucia Thrasher is, quote, an inquisitive noisy bird, and on seeing anything larger than itself passing by, will stand head and tail elevated, wings drooping, and with open mouth keep up a constant warning chatter, and throwing itself about in all sorts of contortions. When a mob of them act thus together, as they often do, the scene is an amusing one to the passerby,

and useful, as it often indicates the presence of a snake or of game. End quote. After courtship, the next step in breeding is the nest. The typical mimid nest is a bulky open cup. It's made of coarse twigs on the outside, and lined with finer, softer material like grass, leaves, or thin roots. Northern mockingbird nests have been found with linings made of human garbage. Fun stuff like used band-aids, tea bags, laundry lint, and even that fake plastic grass we use to stuff Easter baskets.

Mimid nests are generally hidden in dense vegetation, in a bush or a tree, usually up to six feet or two meters off the ground. desert species often nest in a cactus. Depending on the species, the male or the female might build the nest or both. In Thrashers, the male and female work together to build the nest. For the northern mockingbird, it's the male that begins the process, constructing the outside of the nest. Sometimes he makes several nests, and then the female comes along and chooses one. Then she finishes lining the nest with material on the inside.

If she's got a real flare for interior design, she might choose stylish things like dental floss, aluminum foil, or cigarette butts. And apparently those fearless Galapagos mockingbirds have, at least on one occasion, snatched hair off the heads of people to line their nests. The eggs of mimids are typically blueish or greenish, often speckled with dots. Clutch size varies among species from two. to seven eggs. In many species, it's both the male and the female that participate in all aspects of parental care. The chicks hatch after somewhere around 12 days to two weeks, and they're altricial, so they're blind, helpless, and mostly featherless. Nestlings remain in the nest for about 10 to 15 days. The fledglings continue to be fed by their parents for up to

three weeks, but this phase can be much longer in cooperatively breeding species like the Galapagos mockingbirds. Some species, including the northern mockingbird, are known for their ability to really crank them out when it comes to breeding. That species has been observed making up to seven rounds of nesting in a single breeding season. One female northern mockingbird even laid 27 eggs in one season. That is some impressive high output reproduction for a songbird. lifespans for mimids are uncertain for many species. But we know that the northern mockingbird can live up to eight years in the wild, at least, and up to 20 years in captivity. Wild brown thrashers have lived almost 11 years.

The pearly-eyed thrasher, Margarops Fuscatus, is known to have a relatively long lifespan. This species, which is found in Puerto Rico and about 100 other Caribbean islands, can live at least 15 years in the wild. And this species starts breeding at a young age, at around nine months. The long life and early and prolific breeding of the pearly-eyed thrasher, combined with its aggressive behavior and broad diet, all of that together seems to have helped this bird colonize those many islands. So that, my friends, is Mimidi, the family of New World songbirds that sing complex songs with

their fine-tuned syrinxes. Some of them are bold and like to show off in the open, while many others skulk in the shadowy undergrowth. We find them in deserts, shrublands, suburban backyards, and Caribbean forests. Most are generalists, while some are specialists. The diverse diet Myets of mimids include bugs, small vertebrates, and berries, and there are also those Galapagos oddballs that eat ticks and drink blood. Charming, cheeky, resourceful, and endlessly musical, the mockingbirds, thrashers, catbirds and tremblers are an amazing group of birds. That's a wrap on episode 124.

I really hope you enjoyed learning about these birds with me. I plan to make individual episodes for some of these species someday, for the Northern Mockingbird, the Brown Thrasher, and so on. As always, I want to thank my wonderful supporters on Patreon. It's your generosity and support that has allowed me to keep running this podcast and keep it free for anyone in the world to listen to. The newest members of my Patreon community are Rachel Gellenbeck, Bob, Susan Gerritsen Friedman, Kathy, Corda Cordes, Sarah Bardwell, Lori B, Nicole Rehorst, Gizzard, Gizard, Donna, and Jamelin.

Jammelin. A big welcome and thank you to all of you. If you're not a patron yet, but you're thinking about helping the podcast, you can check out my Patreon page over at patreon.com slash science of birds. There's also a link in the show notes. And if you have something you'd like to share with me, please go ahead and send me an email. Maybe you have a comment about the podcast,

or you want to mock me, or you'd like to tell me how you are going to celebrate Christmas this year. In any case, my address is, as always, Ivan at Science of Birds.com. Again, this is episode 124. You can check out the show notes for the episode, along with some hand-picked photos of mimids that I talked about today on the Science of Birds website, Science of Birds.com. I'm Ivan Philipson, and True Fact About Me, I have three tattoos.

So far, a frog, a dragon, and a green jay. I hope to get some more bird tattoos in the near future. The problem is choosing which species, because there are like so many great options. Anyway, thanks again for listening, and I'll catch you next time. Cheers.