How did the Saber-Tooth Tiger Hunt? (Full Episode) | Lost Beasts Unearthed | Nat Geo Animals

[narrator] In the heart of Los Angeles, buried beneath this bustling city, investigators hunt for a lost terror of the Ice Age. The saber-toothed tiger. [Steve Brusatte] The saber-toothed tiger is one of the most iconic extinct animals. [growls] This is a, a machete-mouthed demon. [flesh squelching] The saber-tooth was one of the most fearsome animals ever to walk the earth. A predator armed with canines nearly 18 centimeters long. But how much do we really know about it? [Mairin Balisi] It is a strange animal. There's still a lot of unanswered questions. Now, our cameras have rare access to investigators as they examine prehistoric clues, sealed in a bed of tar for thousands of years. How did the saber-tooth hunt? And did its oversized teeth drive it to extinction? It's extremely sharp, even more pointed than most dinosaurs. We'll travel to a time when giant mammals roamed the earth. Stripping away flesh and bone. We reveal the incredible buried secrets of the kingdom of the saber-toothed tiger. ♪♪ Los Angeles, California. A metropolis of nearly four million people. Here in the shadow of the Hollywood Hills, a remarkable team of paleontologists gears up for work as the city stirs into life. The team is digging in Hancock Park, just off the famous Wilshire Boulevard, home to some of LA's finest buildings. This part of the city is also the location of one of the most extraordinary urban excavation sites in the world. The La Brea Tar Pits. A geological phenomenon that's brimming with millions of fossils from a bygone age. Fifty thousand years ago, Los Angeles was a scrub-like woodland that concealed a deadly secret. Pools of sticky asphalt that trapped any animal venturing too close. Thousands of creatures are buried here, but one stands out. Smilodon fatalis, the saber-toothed tiger. Stronger than a modern lion, with huge, curved fangs, this lost beast is legendary, but its life remains a mystery. How did this super-sized monster survive in an ice age world? And why is it no longer stalking LA today? Dr. Mairin Balisi is an expert on prehistoric carnivores. She's part of the team here at the La Brea Tar Pits. This famous LA landmark lies on top of the Salt Lake oil fields. A huge reservoir of liquid asphalt that flows under the city streets. You can really smell the asphalt. It's like a rotten egg smell. Asphalt is basically the crudest version of crude oil. It's very sticky. You can still see the asphalt bubbling up in this pit. The first people to dig at La Brea were Native Americans who used the pits as a natural source of pitch. In the 1800s, settlers mistook the bones here for the remains of stray cattle. It wasn't until 1901 that they were identified as Ice Age fossils. Today, excavators still find fossils preserved in thick black liquid. Over the last century, they have pulled out more than three million specimens from the tar pits here. From familiar-looking animals such as deer and bison to huge prehistoric predators such as the iconic saber-toothed tiger. This is the classic saber-tooth. Smilodon fatalis. This particular one is missing a good chunk of its canine, but you can tell that it is a saber-tooth. Smilodon is not actually a tiger, just a distant cousin. It belongs to a now extinct branch of the cat family that may have crossed into North America more than two and a half million years ago when lower sea levels created a land bridge with Asia. Excavators have found more than 2,000 of these magnificent beasts here. [Balisi] For such a famous animal, one would think, oh, it's probably oversaturated. But there's still a lot of unanswered questions, and that's why this animal is still actively being studied today. [narrator] The first step towards unraveling the life of the saber-tooth is to retrieve its fossils. It's no easy task. In some pits, the asphalt has dried up. But in others, it is still liquid. Digging here is a slow and messy process. But the reward is worth the effort. Right now, we are walking to Project 23, which is one of the two active excavations ongoing at the La Brea Tar Pits. This project is named after 23 huge wooden crates. They contain tons of solidified asphalt, dug out from a nearby construction site. Each box is crammed with thousands of bones from many different animals. Our next door neighbor here, the LA County Museum of Art, they were excavating for a large underground parking structure where they ran into the skull of a mammoth. And that discovery then jumpstarted this entire project. Hey, Sean! Specialist excavator Sean Campbell works to examine the bones in box number two. So what are you finding today? [Sean Campbell] Uh, so today, we're in a pretty tightly compacted, fine-grained sediment area, mostly silt, clays, or some fine sands. Each crate contains a jumble of bones. Sean must carefully chip away at the rock-hard asphalt to free them and work out which species they come from. Many are not predators like the saber-tooth but plant-eating herbivores. It takes time to develop a trained eye to not only see the fossils, but definitely identify the fossils for what they are. Probably the one you're looking at is part of the pelvis. We're not exactly sure which species yet. Uh, it could be a horse, it could be a bison. It could potentially be a camel. The animals discovered here lived at the end of the last Ice Age, between 50,000 to 10,000 years ago. In the north, huge ice sheets covered what is now Canada. But southern regions like California had a much milder climate. Here, winters could be harsh during the Ice Age peak. But temperatures in the LA Basin were perhaps not that different to today, and hardy forests flourished. You can actually see huge portions of trees, uh, jutting up out of the next level. This is a portion of a seed pod, most likely from a juniper. Roughly all of this material is going to be around 44,000 years old. ...to help make that 3D map. Sean uses laser mapping to plot each of his finds onto a special grid. So this is, this is box two so far. The grid allows him to build up an incredible 3D picture of every single fossil inside the box. Cool! So we are looking at it from the top down? [Campbell] Yes. And so you can see how they're dipped and oriented and angled. [narrator] The more excavators like Sean record their findings, the stranger this site becomes. The number of carnivores, like saber-tooth, far outnumber their plant-eating prey. [Campbell] I have found some spectacular things. I've been excavating for a little under nine years. I have found entire saber-toothed cat skulls, many, many direwolf skulls, tons of coyote skulls, foxes, weasels. We have over a thousand individual saber-toothed cat skulls that are so well preserved that they would be considered near complete. The discovery is puzzling. Plant-eating animals are more numerous in nature. But at La Brea, paleontologists find more meat eaters. Why? Experts think that the tar pits were what's known as a carnivore trap. [deer brays] A single stuck herbivore would lure many predators in search of a seemingly easy meal. But this banquet was a last supper. The predators became stuck themselves and slowly perished. Just a few trapped animals every 10 years over 30,000 years could account for the huge number of saber-tooths found here. La Brea is an unparalleled time capsule. A unique opportunity to study the hunting behavior of this magnificent beast and much more. [roars] Steve Brusatte is a paleontologist from Edinburgh University. [Brusatte] This animal, when it was alive just a few tens of thousands of years ago, it would have been similar in overall size to a Siberian tiger but bulkier. What really sets them apart are these saber canines. And really these things speak for themselves. These are sharp, but they're also very thin, almost like a scalpel blade. [narrator] This monster cat had extremely long canines, even by saber-tooth standards. They could grow up to 18 centimeters long and had serrated edges like steak knives. This made them perfect for puncturing tough hide. But while they were strong at punching down, their extreme length made them weak at resisting sideways forces such as those produced by struggling prey. Smilodon needed to make a fast and clean kill or its teeth could snap. So how did it hunt with teeth like these? [growling] Steve compares Smilodon with its evolutionary cousin, the modern African lion. [Brusatte] if we compare the skull of a modern lion with our saber-tooth, the thing that stands out right away are the teeth. Lions have pretty ferocious-looking canine teeth, but they're nothing like these enormous scalpel-like saber canines that the Smilodon has that creates this vampiric overbite. Today's lions and tigers primarily use their teeth for tearing flesh. They kill their prey by using their powerful jaws to crush their victims' necks. Experts think that the saber-tooth's sharp canines were too fragile to be used in this way. They didn't use those sabers like some knife-wielding maniac just going around with reckless abandon, stabbing things. No, no. Those sabers were precision tools, and they were used more like ice picks to deliver punctures to the throat of their prey. A saber-toothed tiger could open it jaws extremely wide, allowing it to bite down into its prey with full force. It would open its jaws really wide and strike. A sharp, clean bite into the neck of the animal and watch that animal bleed out. And that's very different from how a lion hunts. Smilodon was ferocious, but there was still an inherent danger in the way it hunted. If it bit down on bone, or its prey struggled too much, these super long teeth could fracture. Big cats can't regrow lost teeth. They only get two sets. So how did saber-tooth protect its precious fangs? Jack Tseng is an expert on prehistoric predators at the University of California. He thinks the secret to Smilodon's success began in infancy. When you look at an adult Smilodon skull head on, you see that it's quite intimidating. But it's equally interesting to think about how they grew to be so large and intimidating from kittens. Jack uses CT scanning to investigate the rare skull of a juvenile saber-tooth. It reveals something intriguing. This young cat had not one but two overlapping sets of vicious canines. [Jack Tseng] So you can see here on the screen, this is a photo of a juvenile specimen of a Smilodon with the milk canine already erupted. But also, here we can see inside the bone of the face a section of the permanent canine. The scans are a surprise. Most mammals lose their milk teeth before gaining their adult ones. But on a saber-tooth, the baby canine has a special groove to allow the adult tooth to grow alongside it. [Tseng] We really didn't know until our study exactly how long that those two teeth overlap. And one of the things we found is that the permanent canine and the milk canine coexisted in the mouth for up to 11 months. [narrator] Jack thinks this double set of fangs acted as an insurance policy. [Tseng] By having up to four sets of canines, now a pair of milk canines and a pair of adult canines, juvenile Smilodons may have been, uh, buffered in their ability to make mistakes because they had extra teeth to help them practice their hunting technique. Young saber-tooth could afford to make mistakes. But a fully grown adult had no second chances. It had to stop its prey from struggling to prevent its canines from snapping. Modern lions and tigers use their forearms to wrestle their prey to the ground. So Jack and his colleague Emily Bogner scan the humerus of an adult Smilodon fatalis saber-tooth and compare it to that of a tiger. These are our 3D computer models. On our left, we have our Smilodon humerus and on our right we have our tiger humerus. This simulation shows what happens when the bones are put under stress. The tiger humerus lights up as green, indicating potential weak spots. The saber-tooth humerus is much more robust. [Emily Bogner] So based on these results, they would have been able to handle their prey better, and the humerus would have been able to resist bending and twisting motions better. What that means is their sabers would have been more protected because they would have been less prone to injury. The bodies of the saber-tooth evolved for a very specific style of hunting. It had hugely powerful rear legs which allowed the animal to ambush and leap onto its prey. Its massive forearms then pinned the animal down to prevent it from escaping. -[saber-tooth growls] -[deer brays] Only once it had completely immobilized its victim did it open its massive jaws and risk biting down, severing arteries and leaving its prey to bleed to death. When we typically hear the word saber-tooth, we go immediately to the skull and its outrageously long canines. But when you zoom out a little bit and look at more of the animal, you start to realize that rather than just being like a vampire, the rest of the body is actually quite robust and more in the profile of a wrestler. Evolution gave the saber-tooth an incredible set of weaponry. Its saber-like teeth and hulking physique made it more powerful than any big cat alive today, capable of taking on far larger prey. So what did it hunt? The popular image of the saber-tooth is that of a predator locked in combat with huge Ice Age opponents. Like the giant ground sloth. Outside in Project 23, Sean thinks he may have found the remains of this massive beast. I actually just found some dermal ossicles which are essentially bony marbles that grow in the sloth's skin. Even though it was a small fossil, that tells me later on when I get into the bulk of this deposit where I find very large remains, I'm going to see more of that sloth. [narrator] Giant sloths were huge plant-eating mammals weighing over a ton. They sported formidable claws at the end of powerful arms. A lumbering sloth, especially a trapped one, would have made a hearty meal. So could anything survive a saber-tooth attack? The team at La Brea have found the bones of an even bigger beast in the tar: a Columbian mammoth. It was less hairy than its woolly cousin but far larger. It weighed nearly as much as a bus and could easily grow up to three meters tall with tusks just as long. For many, a mammoth is the classic saber-tooth opponent. But was an animal this big really on a saber-tooth's menu? [bellows] Excavators have discovered the remains of more than 30 mammoths at La Brea. Today, Stephanie is cleaning the skull of a bull mammoth nicknamed Zed, the same animal that kickstarted Project 23. [Stephanie Potze] It's a slow and gradual process. We want to ensure that we don't rush it because the asphalt often obscures what we can see underneath. Zed's skeleton is special. It's almost 80% complete. The skull is upside down. These are actually the mammoth's enormous back teeth. Most of the head is encased in plaster to protect the fragile bone. Columbian mammoths like Zed were very different to their woolly cousins who lived further north, closer to the massive ice sheets. They preferred the milder environment This mammoth probably was not woolly because down here in Southern California, we didn't have the same sort of glaciation as at higher latitudes. So rather, this mammoth, it was obviously large, and it was more of a savannah dweller. Excavators have discovered that Zed was in his late 40s when he died. Mammoths lived, on average, to about 60. But there's no evidence so far that he was torn apart by a hungry saber-tooth. It looked like he died in a stream at La Brea around 37,000 years ago, perhaps as a result of a fight with another bull elephant. Paleontologist Steve Brusatte thinks that the Californian saber-tooth would have avoided prey this big. One trope that you see quite a bit in museum exhibits, in films is this faceoff between a saber-toothed tiger and a mammoth. Like it's Sherlock Holmes and Moriarty. But that probably didn't happen very much. [narrator] Saber-tooths used their powerful front legs A Columbian mammoth like Zed would have been too big and dangerous an opponent. [Brusatte] They were actually bigger than woolly mammoths, so they would have been even bigger than today's elephants. Very challenging prey to take down, even for something as fearsome as a saber-toothed tiger. So normally saber-toothed tigers would probably eat things like bison and deer and tapirs, smaller prey. Analysis of the tooth enamel of Californian saber-toothed cats appears to confirm that they preferred to eat smaller herbivores. The enamel contains radioactive traces of plants consumed by their prey. The results show how saber-tooths were big game hunters, feasting on bison and deer, animals that grazed on the grasses of California. Only a very small mammoth would have been worth the risk. And there are fossils that show this, there is a cave in Texas. It's a den of not Smilodon, but a different saber-toothed cat called Homotherium and in its den, strewn about are the bones of young Colombian mammoths. And those bones are scratched and pitted and really just demolished with the bite marks that match the teeth of the Homotherium. So there were times, at least sometimes, where some saber-toothed cats did eat some mammoths, but this was probably not the norm. [narrator] Discoveries like these transform how we see the saber-tooth. They reveal a very different kind of predator to the one of Hollywood legend. But figuring out how this prehistoric cat behaved is an even greater challenge. is that of a lone killer. Much like today's tigers. Now, new evidence is starting to point to a more social animal. Hidden among the many fossils dug up from La Brea, investigators find the pelvis of a Smilodon fatalis saber-tooth. Its left-hand hip socket looked perfectly healthy. But on the other side, the joint was almost destroyed, with a gaping hole in the surface and the edge of the socket dented like a crater rim. It looks like a debilitating injury likely to have caused pain and severely limited movement. In a finely tuned hunting machine like the saber-tooth, this should have been a death sentence. But this one grew to a ripe old age. How is this possible? Mairin takes a closer look at this strange specimen. For more than a century, scientists thought that the extreme damage to this bone was the result of a hunting injury, like a fracture. [Balisi] Hunting is a dangerous activity, and saber-tooths definitely hunted. So the idea was that this particular saber-tooth that had this hip bone probably was hunting, got hurt, and maybe the hip area got infected, um, and the infection reached the bone and caused the bony growth that we see here. However, recently we collaborated, to CT scan the specimen. And the CT scans revealed no evidence of fracture. There are more than 5,000 saber-tooth bones at La Brea that bear the scars of injuries. But Mairin thinks this one has the hallmarks of a genetic disorder. So this is something that's called hip dysplasia, uh, which we still have in our dogs and cats today. Typically, the ball of the femur would fit nicely into the socket of the hip bone, and they kind of co-develop that way. However, in this case, the socket of the hip bone never truly developed. Saber-toothed cats relied on powerful hips to ambush their prey. But this one walked with a limp. [Balisi] This animal probably could not have moved very well, at least later in its life. And it probably had trouble using its hind limbs to hunt prey. Mairin thinks that this animal could be evidence that saber-tooths lived together in prides like lions. In order to be able to continue feeding on large prey to sustain its growth to adulthood, it probably had some help, and possibly from a family group. It's hard to determine the social behavior of a species from bones alone. But animals who live in family groups usually hunt together. Excavators at La Brea have discovered 4,000 direwolves here. These huge prehistoric predators hunted in packs just like their living cousins. The large number of saber-tooths found at La Brea could be evidence that they did the same. We have over 2,000 individuals of Smilodon. The large numbers that we recover from here are taken as evidence that they were social. Say you have a large herbivore that is entrapped in an asphalt seep. And if you were a saber-tooth and you had some sort of social behavior, then it's likely that you would be roaming around with your family group and come across this herbivore and be entrapped together. In New York, comparative anatomist Joy Reidenberg from the Icahn School of Medicine investigates if Smilodon shared another aspect of its behavior with today's big cats... the ability to roar. Lions and tigers roar as a form of communication. They're informing other lions or tigers in the area that this is their territory and others should stay out. [roaring] Sometimes they also roar to call on a coalition partner. So if lions, for example, are hunting with maybe a brother, they will call that other partner in for the hunt. The key to the lion's roar is the larynx, or voicebox. Unlike many other cats, the lion's larynx has a flexible connection to the skull, via a bone called the hyoid. A powerful set of muscles can pull the larynx deep down into the chest allowing the lion to generate low frequency pulses of sound, louder than a lawnmower, which can be heard up to eight kilometers away. with a very large larynx that has very large vocal folds. And the thicker those folds are, the lower the frequency. I've been around lions roaring, and my whole chest resonates when I hear that sound. I feel it in my body because the frequency is so low. Domestic cats have a very small larynx, and their vocal folds are much more delicate compared to a lion. So they're not capable of roaring because the folds just aren't big enough. [narrator] So did the North American saber-tooth share the same physiology? We don't know what kind of larynx Smilodon had because the larynx being a soft tissue doesn't fossilize. The closest we can come is to look at the bones that move the larynx back and forth. Those bones are called the hyoid bones. Some investigators believe that a set of delicate saber-tooth hyoid bones, found at La Brea, are similar to those in a lion. If true, then the saber-tooth might have been a much more social predator than previously imagined. [Joy Reidenberg] If they had the ability to roar, it might be an indication of social cohesion. Discoveries like this reveal that the saber-tooth was the king of the Ice Age mega-beasts. But there is a mystery. Saber-tooths disappeared from La Brea around 10,000 years ago. A story that's repeated across the world. Why do they no longer prowl the Americas today? At La Brea, excavators find traces of another strange feline. A species called Homotherium... also known as the scimitar cat. [Balisi] This is a fragment of a canine of Homotherium. This is... these are various, um, little toe bones. Compared to Smilodon, the scimitar cat is almost invisible This is all we have of Homotherium at the La Brea Tar Pits thus far, which suggests that they may have been around, but they were not around in great numbers. The lack of finds here is deceptive. The scimitar cat was among the most successful of all the saber-toothed cats. This beast had slightly shorter fangs than its Californian cousin but made up for it in size. Standing taller than the average Smilodon fatalis and weighing in at 190 kilos, it was also much more widespread. While Smilodon stayed home in the Americas, lived all over the Northern hemisphere, from sunny Texas to chilly France. Why was this animal so successful and why, like Smilodon, does it no longer roam the globe today? Ornella Bertrand from Edinburgh University on the evolution of mammals. She compares these two monster cats. One reason why paleontologists find fewer scimitar cats in California is that these animals preferred a different habitat. [speaking French] Ornella thinks that each cat was perfectly adapted to suit its chosen environment. [Ornella Bertrand speaking French] [narrator] Scientists used to think that in Europe, scimitar cats went extinct around 300,000 years ago, well before Smilodon. But the recent discovery of a jawbone from the North Sea has cast doubt on this theory. It dates to around 28,000 years ago and shows that the scimitar cats were still alive and well here. It's now increasingly likely that both saber-toothed cats disappeared around the same time. Why did these two animals, that preferred such different habitats, share the same fate at the same time? Saber-toothed cats weren't the only animals to vanish 10,000 years ago. The end of the Ice Age saw mass extinctions all over globe. But unlike the asteroid that wiped out the dinosaurs, this one eliminated only big mammals. Mammoths, woolly rhinos, ground sloths, and saber-toothed cats all disappeared. The extinction of the Ice Age mega-beasts is one of the greatest mysteries of paleontology. Some scientists blame climate change. The Ice Age was not the single big freeze of popular imagination. Temperatures fluctuated. Some species may have been unable to adapt fast enough to changes in their habitats. But why did this extinction primarily affect big mammals? One of many paleontologists with a disturbing theory is Steve Brusatte. He thinks the downfall coincides with the rise of another species. Humans. [narrator] The exact date when humans arrived in North America is hotly contested. But radiocarbon dating shows that people overlapped with Smilodon by at least 2,000 to 3,000 years. The last saber-toothed tigers, the last Smilodons died out about 10,000 years ago. So really, really recently. And at that time, there had already been humans that had come to North America and South America where they lived. And it was probably the activity of those humans, of our ancestors, that ultimately led to the demise of the saber-tooths. Humans and big cats are both apex predators and natural rivals. There's no evidence that people deliberately wiped out these cats. But one theory is that modern humans decimated the big herbivores that big cats relied on for food. Huge mammals like Columbian mammoths had never encountered people before and perhaps didn't see them as a threat. Steve thinks our impact was both insidious and deadly. A number of species of large mammals all died out around the same time about 10,000 years ago at the end of the last glacial pulse of the Ice Age. And that's not to say that we over-hunted everything, we killed everything in that sort of direct, murderous way. That was maybe part of it. But we had such a profound effect on the environment wherever we went. And what we see in the fossil record is as humans migrated around the world, big mammals died soon afterwards. The evidence is circumstantial. But what is clear is that humans were able to change their environment in ways that no other animal had ever been able to do. Many scientists believe that humans disrupted an already stressed ecosystem. [Brusatte] Yes, there were climate changes happening. The Ice Age was changing, the glaciers were melting, it was becoming warmer. But that had happened so many times before. But what was different about this time? This time, there were humans around. So it was maybe that one-two punch of humans hunting these animals, changing their environment, changing their ranges, hunting their prey species, along with the climate changes that conspired together to doom So why did big cats like lions and tigers survive? The answer could lie not with the saber-tooth's final days but its earliest beginnings. The Alf Museum in Claremont, a few miles outside La Brea, is home to an astonishing collection of fossils that spans almost the entire history of life on earth. The finds include the remains of once mighty dinosaurs. 170,000 specimens here. Hidden deep inside the museum's vault lie saber-tooth's surprising ancestors. [Balisi] This is a Smilodon, the Californian saber-tooth. Probably the most well-known of all the saber-tooths. But we certainly have many other saber-tooths from various other points in time. [narrator] Mammals with saber-like teeth have evolved at least four times in the history of our planet. Paleontologists call this convergent evolution. When unrelated animals develop the same features or adaptation independently. What we have in front of us are what I would call precursors to the saber-toothed Smilodon. This Smilodon is from tens of thousands of years ago. And these are much older. So from about 30 to 45 million years ago. Animals like these with highly specialized adaptations are often remarkably successful. The evolutionary advantage of having a long saber-tooth is that, well, you basically have two large stabbing knives at the front of your skull. This adaptation makes them the apex predator in their respective environments. [narrator] But specialists are also among the most vulnerable to change. Smaller, less specialized animals, like modern-day coyotes or raccoons, are better able to adapt to a changing world. They can eat basically whatever they wish. So a raccoon can subsist on, you know, modern-day human trash. However, larger-bodied carnivores, they need to eat a lot. Smilodon was specialized in that way, in that it needed large body prey in order to survive. had evolved as an ambush predator. Instead of chasing its prey down like a modern lion, it lurked in the shadows... waiting to pounce upon its unsuspecting prey. Which it then dispatched with its vicious fangs. One theory is that the saber-tooth struggled as the larger-bodied herbivores it preyed on started to decline. The same massive teeth that brought this beast to the top of the food chain may ultimately have sealed its fate. Every species has an end date, and part of that has to do with their specialization. So if your prey species that you specialize on goes extinct, then you probably will go extinct as well. [narrator] Today, the saber-tooth is gone. All that remains of this magnificent predator is their astonishing fossils from places like La Brea. But the final chapter to this story may not be written. Mairin believes that the world may not have seen the last of the saber-tooth. I think that even though we no longer have these specific given that this specialization repeatedly arose over millions of years in different branches of the mammalian family tree. I think that there's a good chance that our descendants might see a saber-toothed cat or something like it in the far future. A highly successful apex predator, honed by millions of years of evolution, Smilodon fatalis was a wily hunter who used both skill and brawn to ambush its prey. And a much more social animal than we ever imagined. The super-sized fangs that made the saber-tooth the king of the Ice Age also doomed it to extinction. But this lost beast is a true superstar who deserves its place on the Hollywood walk of fame and may one day prowl these streets, or others like it, again.