Shrikes

I was recently in Utah, leading a birding slash geology tour through several national parks. My group and I were out exploring a wetland one morning, driving slowly along a back road in our van. Already the birding had been lots of fun. We'd seen peregrine falcons, sandhill cranes, mountain bluebirds, and many other great species. So we were driving along slowly when suddenly there was a small flash of gray and white that flew across the front of the van.

We followed the movement to see that there on the side of the road a few feet away was a loggerhead shrike. But the shrike was not alone. The shrike was in a wrestling match with another bird. But this was no game. It was a matter of life and death. My group and I watched in fascination and, honestly, a little bit of horror as the shrike made the kill. The other bird stopped struggling and went limp.

Now we could see that the poor little thing was a vesper sparrow, a species about three-quarters the size of the shrike. The shrike dragged its victim through the dust up into the cover of a twiggy bush. like a miniature leopard hauling its prey into a tree. Wow, this dramatic scene was one of the wildest things I've seen while out birding.

I was sad for the Vesper sparrow, naturally, but I also felt lucky to see a loggerhead shrike in action. After all, a shrike is a songbird that behaves more like a miniature raptor. This is true for all the shrike species of the world. They're fierce little predators that fuel the nightmares of insects, reptiles, small mammals, and small birds. 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 75. It's all about shrikes. Birds in the family lineidae. These are true songbirds, members of the avian suborder Passerai within the order Passeriformes, even though they act and sort of look like tiny falcons or hawks. Shrikes are sit and wait predators. They typically sit upright on an exposed, conspicuous perch and then wait for something tasty to come along.

Some small animal, like a vesper sparrow, a rodent, lizard, grasshopper, and so on. Around the world, there are many other birds with the word shrike in their name. We've got wood shrikes, helmet shrikes, shrike flycatchers, flycatcher shrikes, shrike tyrants, shrike babblers, shrike thrushes, shrike tits, shrike bills, and the list goes on.

And in case you're wondering, those are real birds. I'm not joking for once. But why did the bird naming committee stop there? I've got some suggestions here for other bird names. How about Flamingo Shrike? Shrikey McShrikeface, Shrike it rich, or Shrike Turkey. Anyway, the birds we're talking about today are the true Shrikes. The ones that got the name first. The family Laniidae also includes seven bird species in Africa that are called fiscals rather than shrikes. That's F-I-S-C-A-L.

There's the gray-backed fiscal, for example, and the long-tailed fiscal. The word fiscal comes from a Dutch word spelled F-I-S-K-A-A-L. Hundreds of years ago, the fiscal was a person who went around collecting taxes from people. So I imagine these were very popular people, loved by all, because everybody loves tax collectors.

A tax-collecting fiscal went about their business wearing black and white clothes. And that's how the birds got this name, because of their black and white plumage. And, of course, this is where the English word fiscal comes from. as in fiscal year, fiscal policy, and so on. How is a fiscal, the bird, different from a shrike? Well, as far as I can tell, there really isn't any meaningful biological difference.

They just have different names. Anyway, henceforth, I shall refer to birds in the family Laniidae as shrikes. But just keep in mind that some of them are called fiscals. Shrikes are such cool birds that they have many fans among birders and ornithologists. In fact, there's a sub-discipline of ornithology called shrikeology, for real. And those who study these fascinating birds are known as, you guessed it, shrikeologists. So for today, at least, let's all be honorary shrikeologists.

Let's get down to the nitty-gritty details of Shrike biology. As always, we begin by talking about the key features of birds in this family, what they look and sound like. All shrikes have a very similar body structure. In general, they're medium-sized songbirds. Their bodies are stocky with relatively large heads and short necks. That's where the loggerhead shrike gets its name.

Calling this bird a loggerhead is pretty much the same as calling it a blockhead, because the word loggerhead means having a disproportionately large head, like Charlie Brown or Stewie Griffin from Family Guy. or those Funko Pop collectible figurines. And you know, if there was a Funko Pop figurine of a loggerhead Shrike, I might actually buy that. Most Shrikes have medium to longish tails.

The magpie shrike of southern Africa, Lanius melanolucus, has the most impressive tail of all. It's longer than the rest of the bird's body. All shrikes have a strong bill with a hooked tip. The bill looks a lot like that of a falcon. Besides the hooked tip, shrikes and falcons share another important bill feature, the tomial tooth.

This isn't a real tooth because birds don't have teeth, but it's a little pointy protuberance on the upper bill, located just behind the hooked tip of the bill. There's one tooth on each side of the bill. I talked about tomial teeth in episode 16 of the podcast, which was about the peregrine falcon. As I was reading about the beaks of shrikes, I came across a fun new vocabulary word, dente rostral.

It's spelled D-E-N-T-I-R-O-S-T-R-A-L. This was new to me anyway. Dentorostral means having a toothed or notched bill. I'll come back to this beak feature in a few minutes. It plays a key role in how shrikes tackle their prey. Shrike bills are black or gray across the species. But there's one exception, one outlier. the yellow-billed shrike, Lanius corvinus. I think you can guess what color its beak is.

Besides the anomalous bill color, this species is unusual for Shrike because its plumage is an overall streaky brown and cream. It doesn't have the typical high-contrast black-white-gray combo of most other members of the family. The largest shrike species is, perhaps not surprisingly, the giant shrike. Lanius Giganteus. This absolute beast of a shrike lives in the temperate forests of central China.

Children in that region are warned not to go into the woods because if they do, they're probably going to get eaten by the giant shrike. Okay, it's not actually that large. It's only about 11.8 inches or 30 centimeters and weighs 3.5 ounces, which is about 100 grams. And to be fair, a closely related species, the Chinese gray shrike, is about the same size.

The world's smallest shrike species is Emmons shrike, Lanius gubernator. This little bugger is only about 6 inches long, or 15 centimeters, so half the size of the giant shrike. Emmons strike weighs just 0.89 ounces, or 23.5 grams. It's found in open habitats across equatorial Africa. The Loggerhead Shrike is intermediate in size with a length of 8.26 inches or 21 centimeters. It weighs 1.6 ounces, which is 47.5 grams.

so about half the weight of a giant shrike. Over in Europe, one of the most common species is the great grey shrike. It's a bit larger than the loggerhead. The plumages of shrikes are some combination of black, gray, white, buffy brown, or rufous. So they're not what you'd call colorful birds. But their plumage has a lot of bold contrast. They're stylish and handsome. The feathers of the forehead and crown are either gray, black, or brown. The same is true for the upper parts in general.

Pretty much every Shrike species has a black mask across the eyes. You know, like Zorro or a raccoon or the Hamburglar from McDonald's. In contrast, the underparts of Shrikes, their chins, throats, and bellies are typically much paler. So hopefully we're all on the same page about the basic appearance of Shrikes. Now let's have a listen to some of their vocal sounds. The word shrike evolved from the old English word shreech. That sounds kind of like the word screech or shriek, doesn't it?

That's because these words screech, shriek, and shrike all have a common origin in Old English. So shriech might originally have been a reference to the bird's shrill call. One of my references pointed to a different origin, claiming that shrike comes from the Icelandic word skrikja, which means a scream. Although they're technically songbirds, shrikes aren't all virtuosos when it comes to singing. Some would say their vocal sounds are a bit limited. How about an example?

Here's the blood-curdling scream and some other calls of the loggerhead shrike. This individual was recorded in southern Arizona. Okay, so maybe not so blood-curdling, I guess. To me, those calls are actually kind of cute-sounding. But I won't be fooled, Shrike. I know you're a stone-cold killer. I've seen what you can do. This next bird is a great gray shrike, Lanius excubator. You can find this species across a large swath of Europe, Western Asia, and Northern Africa.

This individual was recorded in Oman on the Arabian Peninsula. Again, that was the great greyshrike, or as the Germans call it, nine murder. Because, as folks in ye olden days would tell you, this rapacious predator kills nine birds a day. No more, no less. Always nine. Ah, superstitions. Gotta love them for their creativity, if nothing else. Next, we have the alarm call of a red-backed Shrike, Lanius Collurio. recorded in South Africa.

Another species common in South Africa is the southern fiscal, Lanius calaris. In this recording, a southern fiscal is making something more like a song. The bull-headed shrike, Lanius bucephalus, which might well have been called blockhead shrike, is an East Asian bird. Here's a bull-headed shrike recorded in South Korea. Over in Cambodia and other parts of Southeast Asia, we've got the Burmese shrike, Lanius colluriodes. It, too, can sing a somewhat melodious song.

Okay, one more. A handful of shrike species are cooperative breeders. This is a breeding system where young birds are raised not just by their parents, but also other birds in the group. Cooperative breeding Shrike species tend to be more vocal. Perhaps they need to be in order to share information among group members. So here is the yellow-billed Shrike.

Remember that species? The only shrike with a bill that isn't gray or black? The one with a streaky brown plumage? Well, the yellow-billed shrike is also, unlike most other shrikes, a cooperatively breeding species. Here's one recorded in Kenya. The last thing I want to say about the vocal abilities of shrikes is that there's at least one species that seems to mimic the calls of other birds, but not to impress potential mates, like, say, the northern mockingbird.

The northern shrike, Lanius borealis, mimics the sounds of small songbirds for a more diabolical reason. It makes its calls and then waits for another bird to come investigate. If that happens, the Shrike will pounce and attempt to commit bird murder. So far, there isn't a ton of data to support this idea that the Northern Shrike uses vocalizations to lure in hapless prey. But it's an intriguing possibility, don't you think?

Now it's time for the segment on the diversity of Shrikes, their global distribution, and their habitats. The name of the Shrike family is Laniidae. You've heard me say the scientific names of a bunch of Shrikes already. And the genus for all of them is what? Lanius, right? That's where the family got its name. The word Lanius itself is derived from the Latin word for butcher. You know, because of all the bird murder and what have you.

Nine murders a day if you're talking about the Great Gray Shrike. A common nickname for a Shrike is Butcher Bird. So there you go. I should point out that it's not entirely clear... to me anyway, what the quote-unquote proper pronunciation is for the genus Lanius. Some might say Lanius, others might say Lanius. A couple reputable sources, including the book Latin for Bird Lovers, say that the correct pronunciation is Lanius, so that's what I went with.

If you, dear listener, happen to be a professional shrikeologist and you want to correct my pronunciation, please do. Honestly, I spend way too much time trying to figure out the correct pronunciation of these biological terms, most of which are based on Latin. If I spent half as much time actually writing my podcast scripts as I do going down multiple pronunciation rabbit holes, well, I'd probably have published 500 episodes by now instead of just 75.

Oh well, I can't help myself. Anyway, butcher birds. Now, if you live in Australia, you might be thinking, Oi, we've got butcher birds all over the place down here. There's the grey butcher bird, the black butcher bird, the pied butcher bird. We got heaps of them. To you, Mr. Australian man with an incredibly authentic accent, I would say this.

Yes, you have butcher birds, but those species are only distantly related to shrikes. The seven species of butcher bird in Australia are all in the genus Cracticus, and they belong to a totally different family. Artemidae. I'm sorry, but there are no members of the Shrike family living in Australia. Now, let's have a look at what other birds are related to Shrikes.

While it's not 100% clear who the closest relatives of Shrykes are, some recent studies suggest that the family most closely related to Laniidae is Platilophidae. The family Platilophidae contains just one species, the crested shrike jay, Platilophus galloriculatus. This black bird with a crazy long crest sticking out of its head lives in Southeast Asia.

There's a good chance you've never heard of the crested Shrikejay. But the other family that's closely related to Shrikes is one I'm sure you know, Corvidi. That's right. Corvids, as in crows, ravens, jays, magpies, and all those clever critters. Everybody loves Corvids. Given that fact, you might wonder why I haven't done a podcast episode on the family Corvity.

All I can say is patience, my friend, patience. We will get there. As for the family lineidae and its diversity, there are 34 species of laniids. The vast majority of those species are in the genus Lanius, which you've probably guessed since that's the only Shrike genus I've mentioned so far. The remaining two species are in the genus Eurocephalus. A study published in 2019, however, makes a pretty good case that these Eurocephalus birds are not closely related to other shrikes.

The authors of that paper suggest that the Eurocephalus birds should be kicked out of La Neidae and then placed in their own little family. So that might happen at some point. The phylogeny of shrikes, the branching pattern of their evolutionary relationships, is still a little fuzzy to us. But something that's much more clear is the distribution of shrike species around the world.

Birds in this family are found in many places around the world, but species diversity is concentrated in Africa and Eurasia. Africa is home to 24 species. One of the most commonly observed there is the southern fiscal. Asia has 18 species, with the long-tailed shrike being one of the more common species. You'd think the long-tailed shrike would have the longest tail of any species in this family. But nope, the magpie shrike I mentioned before wins hands down.

Anyway, the red-backed shrike is perhaps the best known of the 11 species in Europe. How about here in North America? Well, we've got just two species. the loggerhead shrike, and the northern shrike. The loggerhead is by far the one most Americans would run into. This species lives year-round in the lower half of the U.S. and all the way down to southern Mexico.

In summer, some loggerheads migrate into the northern states and into southern Canada. The northern shrike looks very similar to the loggerhead, but it's a slightly larger, beefier bird. Northern shrikes are denizens of the boreal forest. They breed in the high latitudes of both North America and Asia. In the U.S., we see northern shrikes pretty much only in winter.

These birds migrate south at that time of year. Some other shrike species are similarly migratory, while others tend to stick around in the same region all year long. A few species, like the Northern Shrike and the Great Grey Shrike, have enormous distributions spanning one or more continents. Meanwhile, other species have a tiny distribution. Newton's Fiscal is probably the most extreme, since this bird is found only on the small island of São Tomé, off the west coast of Africa.

So, for the distribution of birds in the family Leneidae, I've mentioned Africa, Eurasia, and North America. We already established that there are none of these birds in Australia. One species gets pretty close, though, and that's the long-tailed shrike. You know, the one that maybe doesn't really deserve that name. That species distribution extends south to the island of New Guinea.

Interestingly, shrikes are also absent from South America. Sort of like cranes, right? I recently did an episode on the crane family, and those birds are also missing from South America. Very curious. I find these biogeographic patterns like this to be fascinating. But you know what isn't curious or at all surprising? The fact that shrikes are also nowhere to be found on that godforsaken hellscape known as Antarctica.

But in the places where shrikes do live, you'll find them in open habitats, like grasslands, steppe, savanna, semi-arid deserts, and open forests. habitats at the edges of forests are also home to many shrike species. These little predators need some open space in order to see and then swoop down on their prey. So good shrike habitat needs to have prominent places for the birds to perch. Tall bushes, small trees, or snags.

What do we know about the origin and evolution of laniid birds? The oldest known fossil of an ancestral shrike dates to about 7 million years ago. It was found in Hungary. Recent research using molecular data from DNA suggests that shrikes started to diversify between 7.2 and 9.1 million years ago. This took place most likely in Africa. During that time period, open habitats like grasslands were becoming more widespread on the continent.

From their origin in Africa, some shrikes moved outward to establish lineages in Eurasia and, eventually, North America. In my opinion, the coolest thing about the evolution of shrikes is the way they have, over millions of years, become like little raptors. Remember, these are songbirds, but instead of eating tiny insects or seeds...

They hunt and kill small vertebrate animals like birds, rodents, and lizards. Because of their predatory lifestyle, shrikes possess many adaptations that are similar to those of hawks, eagles, and falcons. Similarities between Shrikes and Raptors include their bill shapes, their head and body shapes, their plumage coloration, and, to some extent, their vocal sounds.

And what do we call it when two distantly related groups of birds or other organisms evolve independently to have similar adaptations and appearances? Say it with me. Convergent evolution. Yes, convergent evolution. The bill shapes of these birds, for example, have converged to have a very similar shape, with that hooked tip, because this shape is what works for catching and killing small vertebrates. So Shrikes and Raptors give us a great example of convergent evolution.

Now let's take a few moments to consider the conservation situation with Shrikes. Back in the early 1990s, ornithologists became aware that the distributions of many shrike species seemed to be shrinking significantly over the previous 100 years or so. So these ornithologists got together to form a sort of team of superheroes, officially known as the International Shrike Working Group. They wanted to share their knowledge and work together to study and help Shrikes.

So these people are the real shrikeologists. It's good to know they're out there doing what they can to protect shrikes and to help us better understand the biology of these birds. The main threat to shrikes is, as you can probably guess, habitat loss. In addition, some species have small geographic distributions, and that means they don't have a lot of habitat to start with.

Four members of the family are worse off than the rest. The IUCN Red List includes the Iberian Gray Shrike in the Vulnerable category. The woodchat shrike and loggerhead shrike are both in the near-threatened category. Loggerheads have been declining for a while, and the causes don't seem to be entirely clear. It's probably a combination of habitat loss, pesticides, collisions with vehicles, cats, and climate change. The most threatened Shrike species of all is Newton's Fiscal.

That's the one found only on the island of São Tomé. This bird is in the critically endangered category on the red list. Estimates for the total population of the species are between 50 and 250 individuals. All of them live in one patch of old-growth forest on one island. If that forest habitat is lost, it's likely that Newton's Fiscal will go extinct.

Shrikes are carnivores through and through. They eat a wide variety of small animals. Mostly they eat large insects, but of course they eat as many vertebrates as they can. birds, rodents, reptiles, and amphibians. Most of these prey animals are at least a little bit smaller than the shrike itself. But some laniids, like our northern shrike, can take on much larger prey.

Northern Shrikes have been known to kill rock pigeons. You know, like the pigeons flapping around in our cities. That's pretty impressive. The proportions of which prey animals end up in a particular shrike's diet depend on what's available in the local environment. If there are more lizards around than mice, for example, then it's lizards for dinner!

As I mentioned, shrikes like to sit on an exposed perch to scan for possible prey. They dart out to catch insects or birds on the wing, or they tackle prey on the ground. Now, we should take another look at that beak, the bill of the shrike. We have that fun new word to describe shrikes, denterostral, meaning they have notched beaks. They have a pair of tomial teeth on the upper bill. When a shrike strikes a vertebrate prey animal, it makes a surgical bite to the back of the victim's neck.

Those tomial teeth are adaptations for wedging between the prey animal's vertebrae and then mangling or severing its spinal cord. This can cause paralysis or death. If that's not enough to subdue the prey animal, the shrike will pinch its victim's neck and then shake vigorously, sort of like what you see dogs do with their chew toys. Scientists estimate that the force of this shaking motion on the prey animal's neck can be up to 6 Gs. That's what you might feel riding a roller coaster.

Six Gs applied by a shrike is enough force to break the neck of a bird or a rodent. Pretty brutal, right? But a shrike's got a shrike, yo. It was born a predator and it needs to eat. Shrikes have to depend mostly on their beaks to kill, and to kill as fast as possible. Because unlike true raptors, hawks and falcons and whatnot, Shrikes don't have very strong leg muscles or powerful talons to help subdue prey. Shrikes have the little feet and legs of a songbird, meaning they're relatively wimpy.

Now, that said, some shrike species, the northern shrike, for example, use their bills and their feet to catch other birds. So it's not like their feet are useless or anything. After the prey animal is dead, the next step in the process is, in some ways, even more gruesome. The Shrike hauls its victim over to a thorn or some barbed wire and impales the corpse on the pointy object. Or the Shrike will wedge its prey between some branches.

And this is where the butcher bird really earns its nickname. Because the shrike starts tearing off bite-sized bits of flesh from the impaled or wedged carcass. Shrikes don't have the strong feet and talons of a hawk or falcon, right? So instead, they use the leverage of a thorn or some branches this way to keep the body in place while ripping it to shreds.

You know, this makes me think of Vlad the Impaler, the national hero of Romania that lived in the 15th century. He's famous for the cruel punishments he dealt to his enemies. Like, you know, having them impaled on wooden stakes. This guy was the real-life inspiration for the fictional character Count Dracula. I wonder if ol' Vlad knew about Shrikes.

At least four species live in modern-day Transylvania and elsewhere in Romania. So he had to have seen a shrike now and then, even if he wasn't a birder. So maybe Vlad the Impaler was inspired by the behavior of Shrikes. And then Bram Stoker, the author of the novel Dracula, was in turn inspired by Vlad the Impaler. And all of that led, ultimately, to the Twilight novels and the movies. Masterpieces of modern fiction that they are. So thanks, Shrikes. I guess. Anyway.

A really interesting hypothesis for the evolution of impaling behavior in Shrikes was offered by the authors of a paper published in 2005 in the journal Behavioral Processes. Here's what they wrote. Quote, We believe impaling originated from wedging behavior that occurs among several other groups of birds, including corvids. Accidental impaling during wedging was likely the behavioral precursor for purposeful impaling.

Fidelity to impaling sites led to the creation of caches, which were eventually used by females for male evaluation. Caching allowed males to increase their fitness by using the caches as a display to attract potential mates. End quote. That all sounds to me like a reasonable evolutionary scenario that could have led to impaling behavior in shrikes. But did you catch that? Yes, male shrikes use impaling to impress the ladies.

More on that in a moment. These researchers are suggesting the precursor to impaling was wedging behavior. This is where a bird places a food item into the fork of a tree or shrub or whatever in order to get some leverage on the food item to make it easier to eat. Some other birds might wedge, but only the true shrikes of the family Leneidae regularly practice the macabre art of purposeful impaling.

And in that 2005 paper, when the researchers mention caches and caching, they mean the situation where a bird stores food temporarily. The bird makes a food cache. C-A-C-H-E. Another bonus to this impaling behavior is that shrikes can eat some poisonous insects. For example, there's the eastern lubber grasshopper.

which is normally unpalatable to birds because of defensive toxins in its body. Well, here comes a loggerhead shrike and it snatches up the grasshopper and slams it down on a sharp thorn. The Shrike waits patiently for a couple days before trying to eat the grasshopper corpse. Those toxins break down in a day or two, and what do you know? The grasshopper now makes for a large, tasty meal for our Shrike.

When it comes to breeding, most shrikes are monogamous. One male and one female pair up to raise a family each breeding season. A few species, however, as I mentioned earlier, are cooperative breeders. These include those two Eurocephalus species that ornithologists probably need to move to their own family. as well as the gray-backed fiscal and the yellow-billed shrike. This latter species, the yellow-billed shrike, has cooperative groups of about 12 individuals on average.

In each group, there's only one pair that breeds. The other birds in the group are helpers. They help incubate the eggs, feed the young, and defend the territory. When male and female shrikes pair up to breed, the male puts on a little show for the female he hopes to mate with. As mentioned earlier, he might use his food caches to impress the female. He's like...

Hey lady, look at this beautifully skewered lizard. I did that. I'm a very good hunter. See? Do you see the lizard? Look! I'm a very good hunter. Can we mate now? But if the female isn't yet convinced that this guy is the one for her, he'll likely need to perform a courtship dance for her. The male's ritualized dance moves actually mimic the act of impaling a prey animal on a thorn. He goes through the motions, dipping and bowing in front of the female and twisting his head from side to side.

I found a great video on YouTube of this behavior in red-backed shrikes. Remember that we heard the alarm call of the red-backed shrike earlier, and this species is among the most commonly seen in Europe. I'll put a link to the video in the show notes for this episode so you can see this courtship behavior for yourself. During courtship, a male shrike may also present the female with gifts of food.

This behavior shows up in many bird species, and it's called courtship feeding. It's another way for the male to demonstrate that he is a very good hunter, that he can provide for the female and her young. To see some evidence that males use impaling to attract mates, consider the Great Gray Shrike, a.k.a. the Nine Murder. Scientists have observed that males of this species go around skewering a lot more prey before they mate with a female. Way more than they can eat.

And the places they impale their victims, the caches they make, are placed out in the open, in conspicuous locations. Also, those locations tend to be along the border of the male's territory. In other words, places that a female might see them. But then, after the male Great Grey Shrike mates with his female partner, food caches he makes are placed close to the nest, rather than at the edge of the territory.

These locations are also less conspicuous. And during this time, a larger proportion of the stored prey are actually eaten. So before mating, the male's caches seem to be more for display. whereas after mating his caches are used as actual food storage and processing sites. I mentioned territories. Shrikes are, in general, highly territorial birds.

For their size, shrikes maintain larger territories than most insect-eating songbirds. That's probably because of their need to catch large insects and vertebrates as prey. And shrikes have their specialized need for thorns and whatnot as places to store and process their food. A mated pair of shrikes make their nest within their territory. The nest is a twiggy, messy-looking bowl or cup-shaped structure. It's usually pretty conspicuous, tucked between the branches of a tree or shrub.

Twigs, grass, and other building materials for the nest are gathered by the male, but the female does most of the actual construction work. Depending on the species, a female shrike will lay between two and nine eggs. These are incubated by the female exclusively, but the male is there to help feed the helpless hatchlings.

The parent shrikes will fiercely defend their babies from any predators that enter the territory. Nest predators include snakes, squirrels, raccoons, and other birds like corvids. After two to three weeks, the young shrikes leave the nest. Mom and dad will continue to bring insects and bits of meat to the fledglings for maybe another couple weeks.

then the young shrikes have to strike off on their own they need to learn how to commit their own little bird murders and mouse murders and lizard murders and grasshopper murders The trademark impaling behavior of Shrikes is apparently innate, something programmed by their genes rather than something they need to be taught. Shrikeologists have documented captive-raised shrikes figuring out how to impale prey even without the benefit of observing other shrikes.

The skill still takes a lot of practice, but a shrike usually masters it in just a few weeks after leaving the nest. And then the bloodbath begins. A new generation of dentirostral block-headed butcher birds flies off to terrorize small animals everywhere. Everywhere, that is, except for South America, Australia, and, well, you know where.

That's a wrap for today's dive into the world of Shrikes. What do you think? These are pretty cool little birds, right? I hope you get to see Shrikes out in the wild if you haven't already. I'm always excited to see one. I'm able to make podcast episodes like this because I get amazing support from my patrons on Patreon. So you can thank them for keeping the Science of Birds dream alive. My newest supporters on Patreon are Allie Cat, Hendrika, James Alexander, and Susan Grief.

Thanks so much to all of you for signing up to help. You're making a big difference here. If you, my friend, are thinking about becoming a patron, you can check out my Patreon page over at patreon.com slash scienceofbirds. There should also be a link in the show notes that says support the show. If you have something you'd like to share with me, please go ahead and shoot me an email.

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You can check out the show notes for this episode, which is number 75, on the Science of Birds website, scienceofbirds.com. I'm your loyal host, Ivan Philipson. Thanks for listening to The Bitter End, and I'll catch you next time. Cheers!