[♪ INTRO] Cities are full of wonderful, exciting things, like museums, and nightclubs, and.
raccoons that eat garbage! Yes, animals love our cities, too.
Some of them, anyway.
When humans develop an area, most speciestend to disappear.
But there are some that not only survive inour urban jungles, they thrive there.
We call these animals “synurbic”.
And they’re great examples of just how resourceful and adaptable creatures can be.
Peregrine falcons used to be happy on theirlonely cliffs.
And then humans discovered a wonder-chemicalcalled dichlorodiphenyltrichloroethane—but let’sjust call it DDT because no one should ever have to say “dichlorodiphenyltrichloroethane.
” It was such an effective pesticide that weused it everywhere — to control crop-eating pests, mosquitoes, bed bugs.
During World War II, the military even usedit on body lice! Unfortunately, it harmed off-target species, too.
While DDT isn’t lethal to adult falcons, it weakens the eggshells they produce.
So DDT-exposed falcons ended up making eggsthat were all too easily crushed.
By the mid 1960s, peregrines were dangerouslyclose to extinction.
Thankfully, a breeding program establishedin 1970 helped bring them back.
And that’s where the story gets kind ofweird.
When captive-bred falcons were released backinto the wilds of New England, a good number of them moved to New York City, of all places.
And in the midwestern US, apparently no self-respectingperegrine wants to be caught dead on an uncultured cliff-top.
So now, almost all peregrines in that regionlive in urban areas.
Which might seem kind of odd, but all youreally have to do is ask yourself why anyone wants to live inthe city.
And the answer is obviously the food.
Cities like New York are renowned for theirpizza, pastrami .
the pigeons .
well, maybe not so much forhumans, but the falcons are definitely into the pigeon.
Pigeons another synurbic species, so thereare tons of them, and they’re easy to prey on.
In fact, city falcons have it so good thatthey lay more eggs.
In the wild, a peregrine clutch usually hasthree eggs in it.
But in the city, a clutch can have as manyas five.
Plus, the skyline of a big city isn’t allthat different from the cliffs they used to call home.
Skyscrapers provide high nesting sites nearsteep drop-offs, where the birds can continue to catch preythe way they always have: by diving on it at incredible speeds.
So the falcons probably feel right at home.
Now, raccoons also love cities for the food—thefood we throw away, that is, hence the nickname “trash pandas”.
Though, they aren’t mindless scavengers.
They’ve got real street smarts, and that’sa big part of why they’ve taken so well to urban environments.
Some experiments suggest they’re as goodat solving problems as crows.
And not only that, they’re also capableof understanding cause and effect.
And that makes sense when you look at theirbrains.
Raccoons have as many neurons as dogs, buttheir brains are much smaller, which means that the densityof neurons is more similar to primates.
Of course, the idea that raccoons are supersmart probably isn’t a revelation to anyone who has woken up tothe sight of a week’s worth of trash strewn across the lawn.
Oh look, the raccoons have figured out howto bust into a “raccoon-proof” garbage can.
And the more they’re exposed to human inventions, the smarter they seem to be getting.
Still, you’d think that a creature thisclever could find food anywhere, so it might seem odd that they’d chooseto live where there are tons of really dangerous animals—humans, I mean.
And the first urban raccoons probably didn’tmake that choice.
As cities grew, they took over the raccoon’snatural range.
Once that happened, though, the raccoons went, “Cool, garbage.
” And that was that.
Nowadays, our cities offer up so much foodthat the animals can eat and reproduce to their heart’s content.
For instance, in one park in Fort Lauderdale, Florida, researchers counted roughly 238 raccoons persquare kilometer.
Which is, like, a ton of raccoons—and that’sway more dense than wild populations.
Now, the northern water snake is a fairlyharmless species that looks a little bit like the very venomousnorthern cottonmouth.
Which is pretty unfortunate for them, sincesome people kill cottonmouths on sight.
Even worse, many humans that can tell thedifference still don’t like these snakes.
Oh, yeah, and they spray poop when they’redisturbed.
Which as you can imagine, makes them kindof hard to appreciate.
Still, our antagonism hasn’t stopped thesnakes from moving into big cities.
Like raccoons, the snakes probably took tourban areas because they had to.
We like our cities to be near waterways, and that’s where these snakes live.
But now that they’re used to city life, they seem to prefer it.
Research suggests that when water snakes haveaccess to both natural and urban areas, they choose the urban one.
That could have something to do with an abundanceof hiding places.
They’re often found hiding in stuff thatwe make, like piles of concrete and scrap metal, orthe material we put on riverbanks to prevent erosion.
And having lots of places to hide is greatfor the snakes’ survival, even when there are snake-hating humans around, because most humans know better than to go sticking their handsin a pile of rubble.
And there may also be a thermal benefit toliving in cities.
Like other reptiles, they can’t stay warmenough on body heat alone, so they prefer warmer bodies of water.
And urban rivers tend to be warmer than rivers flowing through natural areas.
These snakes don’t even need natural habitats.
Pretty much any fresh water does the trick.
And we should be pretty excited about that.
In one urban canal in southern Florida, researchersfound that water snakes perform an important service:eating invasive fish.
In fact, invasive gobies make up more than90 percent of the diet of one northern water snake subspecies.
So this snake’s presence is often a win-win—goodfor the snakes and for the surrounding habitat.
But, urbanization is bad news for most bats.
Most species—especially the smaller, slowerones—need darkness to remain safe from high-flying predatorslike owls.
And cities are full of light.
But flying foxes don’t seem to mind.
And unlike raccoons and northern water snakes, who were sort of forced to live with people at first, scientiststhink these fruit-eaters may have moved into citiesby choice.
That’s because people like fruit just asmuch as the bats do.
So, they plant fruit trees in their backyards.
And these trees provide the bats with an abundantsource of food.
Flying foxes might also feel more comfortablein cities because of their warmth.
It’s a phenomena known as the “urban heatisland effect”.
Basically, our artificial structures don’treflect as much heat during the day, and retain it well at night, so the whole area is a bit warmer than nearby wildernesses.
And warmer nighttime temperatures give thebats a nice, even climate for flapping around, stealingfruit, and pooping on peoples’ stuff.
Which has become somewhat of a source of conflict.
You see, flying foxes are pretty big.
Adult grey-headed flying foxes, for instance, have a wingspan of around one meter.
Which means that when they poop, they poopbig.
Plus, they’re noisy, and kind of smelly.
So, people living in cities haven’t beenall that welcoming.
In places like Australia, they’ve takento putting nets or barbed wire around their fruit trees todiscourage snacking —which, sadly, can kill the bats.
And, for a bat, there are other perils tocity life—like, the heightened odds of flying into a powerline.
But still, the free meals do seem to be offsetting the hostile neighbors, as their numbers seemto keep growing.
Mugger crocodiles are a medium sized speciesof crocodile that lives in India.
And they were once really abundant, but thenpeople became fond of crocodile skin bags and belts.
Luckily, in 1972, they became a protectedspecies, and now, they’re on the rebound.
One of the areas where they’re coming backis the Vishwamitri River in Vadodara, India.
Around 250 crocs live in this urban waterway.
And at first, humans in the area toleratedthem because they have religious significance.
humans and crocodiles don’t reallyget along.
And that’s made the city a pretty dangerousplace for both the people and the crocs.
Also, muggers are migratory, so they’reoften killed by cars while attempting to cross roads.
And if that’s not reason enough to leave, the river they live in is extremely polluted.
Basically all of Vadodara’s sewage is dumpeddirectly into it.
But, when officials have tried relocatingthe animals, they tend to come back.
And, weird as it might seem, that’s probably because of all that sewage.
Polluted rivers don’t tend to have a tonof fish, but the crocs can improvise and snag animalslike dogs and goats that wander near the water.
And when that meat’s hard to come by, theyjust feed on refuse.
See, crocodiles are hunters, but they’realso scavengers.
And in an urban environment, they do a littlebit of both.
Researchers even think some of them wouldrather scavenge than hunt, because hunting is more work.
But this life of leisure isn’t necessarilygood for them.
A few of them even appear to be overweight.
But, if things were too bad, there would bea lot fewer of them.
And some experts think that their presencehas been good for the river, too, because they help cleanup some of the waste before it decomposes.
Macaques haven’t always lived in cities.
Their first interactions with humans probablyoccurred in temples, where they were welcomed because of theirreligious significance.
Then, cities were built near and around thetemples.
And as it turned out, city life agreed withthem.
Macaques are actually a lot like us, whichis to say that they’re super adaptable.
They can thrive in all sorts of habitats—like, tropical jungles, temperate forests, deserts, and swamps.
So it probably wasn’t that hard for themto ease into city life.
And, unlike most of the other animals on thislist, the humans in those cities have been prettychill with it.
Sure, they can be a bit of a nuisance, whatwith all the begging for handouts and stealing from anyone whoisn't paying attention.
But they’re good for the economy.
Tourists love urban macaques, and touristsspend money, so there's a whole industry that's grown up around interactingwith city monkeys.
It’s also pretty obvious why the monkeysdo so well.
Foraging for food in the forest is much harder than getting it handed to you just for beingcute.
One temple even has an annual festival whichincludes a feast .
for the monkeys.
In fact, the monkeys have become so dependenton humans for food that when COVID-19 shut down the city of Lopburiin Thailand, the local macaques made the news for brawlingover a pot of yogurt.
But aside from the usual abundance of food, there are other perks for the monkeys, too—like, that the templesprovide safe, protected housing.
Macaques have been hanging out in cities forso long that they’re almost domesticated — almost.
While they’re comfortable around people, they’re nobody’s pet.
They still live in troops and can be reallyaggressive—especially when a person doesn't have or chooses notto give them what they want.
Still, we kind of like having them around, and they aren’t going to leave of their own volition.
So we’ll probably have city monkeys fora long time to come.
When humans built the first cities, they probablythought they were shutting out the rest of the world.
But we’re just one clever animal in a worldfull of clever animals.
So it was almost inevitable that some of themwould come join us in our safe, warm, and abundant urban habitats.
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