UNREAL EVERGLADES – Nature’s Most Dangerous Paradise (Full Documentary)

[00:00:01]This is Everglades National Park.

[00:00:07]From above, it looks like an endless plane of grass and water, flat, still going nowhere.

[00:00:17]But what you're actually looking at is a river 60 mi wide, 100 m long, and in most places only in deep.

[00:00:27]It moves so slowly the current is invisible.

[00:00:33]A million and a half acres sliding south so gently it looks like nothing here moves at all.

[00:00:41]There are no mountains, no canyons, no cover, just a vast open wilderness where the land dissolves into [music] water until you can't tell where one ends and the other begins. And it sits on the seam of two worlds.

[00:01:00]Fresh water bleeding down from the north.

[00:01:06]Salt water pushing in from the sea.

[00:01:08]Where they collide, they build something found nowhere else on the planet. The one place on Earth where two of the water's deadliest hunters live side by side.

[00:01:20]Half the year the rains come and the whole world floods.

[00:01:28]The other half the water pulls back and the land bakes dry, driving every living thing into the same shrinking pools. The heat is relentless.

[00:01:41]The storms are worse.

[00:01:44]And in a place this flat, this exposed, there is nowhere to hide.

[00:01:51]So, how does anything survive out here?

[00:01:56]How do they hunt [music] where the water swallows their prey and raise their young between flood and drought?

[00:02:06]In a place where the hunters outnumber the hunted and something is moving through the grass that no one [music] can stop.

[00:02:16]This is the Everglades like you've never seen it. The deeper we go, the closer we [music] get to the one thing out there that even the predators have learned to fear.

[00:02:37]The Everglades does not end at the mangrove line. It keeps going out through the shallows and into the Gulf, where the seagrass runs for miles in every direction.

[00:02:51]Green sea turtles have grazed [music] these beds since before the park had a name, and a single turtle can eat enough [music] seaggrass each day to keep a patch cropped short enough for the whole flat to stay clear.

[00:03:10]They are the only sea turtle that eats plants as [music] an adult, which turns their fat green. The color that gave them their name has nothing to do with their shell.

[00:03:25]Females come back to nest on the same beach where they hatched, [music] crossing hundreds of kilometers of open ocean, guided by a magnetic map they carry in their heads.

[00:03:39]The same seaggrass flats that hold the turtles also hold something far larger and far slower.

[00:03:50]West Indian manatees move through the shallows at a pace that looks [music] barely alive, grazing on seaggrass for most of the day and surfacing every few minutes to breathe.

[00:04:05]They have no natural predators here and their only real threat from below is cold water. A manity caught in a cold snap cannot regulate its own temperature and will strand itself on the nearest shore trying to find warmth.

[00:04:23]The Everglades is one of the few places in Florida where the springs run warm enough year round to keep a manity alive through winter, which is why the same individuals come back to the same channels every year.

[00:04:38]Where the manatees drift slow and solitary, the dolphins work in groups, and they have learned to use the same shallow flats in a way almost no other dolphin population does.

[00:04:55]Bottl-nose dolphins here drive fish onto mud banks with a surging rush that beaches both the fish and themselves, then slide back into the water with a catch before the shore can hold them.

[00:05:11]The technique is called strand feeding and the calves learn it by watching. It is not instinct. It passes from mother to calf like a skill.

[00:05:24][music] The dolphins know the channels and so do the sharks.

[00:05:33]Bull sharks are the only large shark that can move freely between salt water and fresh. And they push far into the Everglades interior, up rivers, into brackish lakes, into water that has no taste [music] of the ocean left in it.

[00:05:52]They are responsible for more attacks in shallow inshore water than any other shark, partly because they go where people go. and the Everglades gives them almost unlimited room to do it.

[00:06:07]In the same channels where the bull sharks hunt, something else moves in off the Gulf every spring.

[00:06:17]Tarpon can reach nearly 2 1/2 m long.

[00:06:19]And when one takes a lure, it goes airborne in a series of crashes that can last several minutes. A fish behaving like something trying to escape gravity.

[00:06:32]They breathe air as well as water by gulping at the surface which lets them survive in the oxygen poor backwaters of the Everglades interior where most fish of their size could not last a day.

[00:06:48]Above the tarpon channels, the sky has its own hierarchy.

[00:06:54]American white pelicans do not dive like their brown cousins. They work in coordinated lines across the surface, hering fish into tight pockets before scooping them up together. A hunting strategy that requires a dozen birds moving in synchrony.

[00:07:15]Each bird can hold more than 10 L of water in its pouch. And in a single cooperative sweep, a flock can clear a shallow flat in minutes.

[00:07:29]The pelicans do the work, and the frigate birds collect the tax.

[00:07:38]The magnificent frigat bird cannot land on water. Its feathers are not waterproof enough, and if it goes in, it will drown. So, it never hunts for itself at the surface, relying instead on harassment, chasing boobies and pelicans until they drop their catch, then catching the stolen fish before it hits the water.

[00:08:01]It has the largest wingspan [music] to body weight ratio of any bird alive.

[00:08:06]Built for speed and endurance in the air, which is the only place it is safe.

[00:08:16]While the frigat birds work the air, the oldest travelers in these [music] waters move through the dark below.

[00:08:26]Loggerhead sea turtles have a jaw strong enough to crush conch shells and horseshoe crabs, [music] and they come to the Everglades coastal waters to feed on the hard-shelled prey that most predators cannot touch.

[00:08:44]Females nest on the Atlantic beaches east of the park, crawling ashore at night to dig nests above the tide line.

[00:08:51]And the hatchlings that make it to the water will [music] spend decades at sea before they return.

[00:09:02]The strangest predator in these shallows was nearly gone before anyone thought to look for it.

[00:09:10]The small tooth sawfish uses the tooththed rostrm projecting from its snout to slash through schools of fish, then circles back to pick up what it stunned. A hunting method unchanged for millions of years in a fish that can reach 5 m.

[00:09:31]The Everglades is now the last stronghold for this species [music] in the entire United States, which tells you something about how much of [music] what used to live along these coasts has already disappeared.

[00:09:46]Pull back from the open water and the bottom rises. The sea giving way to the vast shallow flats that make the Everglades unlike [music] any other wetland on Earth.

[00:10:01]The great blue heron owns these flats the way a patient hunter owns a deer stand. It can stand motionless in ankle deep water for 20 minutes without moving a feather, then [music] strike faster than the human eye can follow.

[00:10:18]It will eat almost anything it can swallow whole. Fish, frogs, snakes, small alligators, [music] and on rare occasions other birds. all taken with [music] the same single lunge of that spear-shaped bill.

[00:10:36]A heron that [music] picks the wrong spot can go a whole day without catching anything and then make up for it in a single hour when the tide brings the fish in.

[00:10:50]The heron works the surface from below and the osprey works it from above.

[00:10:55][music] And between the two of them, very little in the shallows gets any peace.

[00:11:02]The osprey [music] hits the water feet first at speed, grabbing fish in talons that have a reversible outer toe specifically for [music] gripping slippery prey. And it almost always rotates the fish head forward before flying off. an aerodynamic adjustment made midair without [music] thinking about it.

[00:11:25]It catches a fish on more [music] than one in four dives, which is a better success rate than most large predators manage on land.

[00:11:36]Where the osprey [music] works alone from height, the snowy egret feeds in a way that looks almost frantic, shuffling its bright yellow feet through the mud to flush small fish. then stabbing at whatever moves.

[00:11:52]The yellow feet are not decoration.

[00:11:53][music] They startle prey into motion in water too murky to see through, turning the egret's feet into bait.

[00:12:05]In the 19th century, the snowy egret was nearly [music] hunted to extinction for the long breeding plumes it grows in spring. And the campaign to stop that trade became one of the founding moments of the American [music] conservation movement.

[00:12:24]The egret hunts by sight and speed, but the Woodstock hunts [music] by feel alone, wading slowly through cloudy water with its bill hanging open, snapping shut the instant [music] anything touches it with a reflex that closes in under 25 milliseconds.

[00:12:44]The woodstock needs water levels to [music] drop enough to concentrate fish into pockets before it can feed efficiently. Which means it is entirely dependent on the seasonal flooding cycle that humans have been trying to manage for the [music] better part of a century.

[00:13:02]When the water [music] management goes wrong, the woodstocks do not nest. The colony simply skips the year.

[00:13:13]Moving through the same shallows, something catches [music] the light in a way that seems wrong for a bird. A deep pink that looks almost artificial against the gray green water.

[00:13:28]The rosette spoon bill sweeps that flatten bill side to side through the mud in a motion that feels mechanical, straining out small crustations and fish by touch while its eyes are looking somewhere else entirely.

[00:13:49]The pink color comes from the shrimp it eats concentrated in the feathers the same way flamingo pink works. So a spoon bill kept away from its natural diet will slowly fade to white.

[00:14:04]The spoon bills and the ibis often feed the same flats at the same time. And where one goes the other follows because the disturbance one bird [music] makes flushing prey through the mud is exactly what the next bird needs.

[00:14:22]White ibis probe deeper into the sediment with that curved bill, pulling out crayfish [music] and small crabs that the spoon bills and egrets cannot reach. And in the dry [music] season, they can cover enormous distances between roosting sites and feeding flats in a single day.

[00:14:43]Juvenile ibis are brown and white and they stay that way for nearly 2 years before the adult white plumage comes in.

[00:14:50]Long enough that young birds look like an entirely different species.

[00:14:59]The ibis takes the crayfish the spoon bill [music] cannot reach and the limp king goes one step further. It has a bill tip that curves slightly to the right, specifically to extract apple snails from their shells without breaking them.

[00:15:16]The Lkins call sounds like someone in serious distress and carries for more than a kilometer across open water, which is why early settlers called it the crying bird and once heard it is almost impossible to forget.

[00:15:33]It is so dependent on apple snails that when an invasive snail [music] species began competing with the native apples snail in Florida, limpkin populations track the decline [music] almost perfectly.

[00:15:50]Back from the water's edge, where the flats give way to the open, wet prairie, a different bird works the grass on foot.

[00:16:02]Florida sandill cranes pair for life [music] and return to the same nesting territory year after year. And the calls they make together, a rattling, bugling duet, are among the loudest sounds produced by any bird their size.

[00:16:20]They probe the wet prairie for tubers, frogs, snakes, and insects. And a crane that learns a productive patch will return to it across multiple seasons, carrying that knowledge [music] for decades.

[00:16:36]The cranes hold the open [music] prairie, but out on the lily pads where no wading bird could follow, the purple gallle walks on water.

[00:16:47]Those oversized yellow green feet distribute its weight across floating vegetation the way snowshoes work on snow, letting it [music] cross pads that would sink under anything heavier. And the result is a bird that looks tropical, electric purple and sky blue, wandering across a surface that should not hold it.

[00:17:13]The chicks that hatch on those same lily pads inherit none of their parents' [music] calm. They fight each other for food from almost the first day. The stronger ones shouldering the weaker aside [music] with a ferocity that looks out of place on something the size of a fist.

[00:17:31]At the edge of the lily pad zone, where open water meets the marsh grass, the mottled duck keeps to itself.

[00:17:40]It is the only dabbling duck that stays in Florida year round rather than [music] migrating. And the entire world population lives in this narrow coastal corridor from Florida to Texas. A bird with almost no [music] room to spare.

[00:17:58]Move deeper into the Everglades interior and the open flats give way to dark sloughs. Channels of slow water cutting through the sawrass. And at the center of almost everyone, an alligator.

[00:18:11][music] American alligators built this place as much as they live in it. [music] The gator holes they excavate with feet and snout hold water through [music] the dry season when the surrounding marsh dries out completely. And those holes become the refuge [music] that keeps fish, turtles, snakes, and birds alive until the rains return.

[00:18:39]The patience that makes the alligator a good excavator also makes it a hunter that can hold position for hours. And in nesting season, it has learned something that looks almost like tool use. Holding sticks on its snout near bird rrookeries, waiting for birds collecting nest material to come close enough to [music] take.

[00:19:04]The alligator rules the fresh water, but where the Everglades meets the sea, there is another [music] reptile. One that most people do not know exists in the United States.

[00:19:18]The American crocodile is a saltwater animal where the alligator is a freshwater one. And Florida is the only place in the world where both species share the same territory, occasionally the same water, though the two rarely interact directly.

[00:19:36]The crocodile population here is one of the northernmost in the world and one of the few that has genuinely recovered over the past few decades.

[00:19:44]It is now the conservation success story the Florida panther has yet to become.

[00:19:53]Where the crocodile holds the brackish zone, the cottonmouth holds everything between the ditches, the pond edges, the slow dark channels that connect the sloughs to the sawrass.

[00:20:07]The Florida cottonmouth [music] is the only venomous water snake in North America. And unlike most venomous snakes, it stands its ground rather than retreating, opening that whitelined mouth as a warning that is impossible [music] to misread.

[00:20:25]It hunts fish, frogs, and small mammals, and it is fully at home underwater, hunting with its head submerged for minutes at a time.

[00:20:38]The cottonmouth is not the only ambush predator working the slough bottom.

[00:20:45]The Florida soft shell turtle buries itself in the mud with only its long tubular snout breaking the surface like a snorkel. And when something edible passes overhead, it erupts from the silt with a strike fast enough to catch [music] fish.

[00:21:06]That leathery shell, so different from the hard dome of other turtles, lets it move through the water with a speed that hardshelled turtles cannot match.

[00:21:20]Above the sleuth, the anhinger fishes in a different way entirely, diving deep and spearing fish with a bill that works like a javelin, the neck cocked back and released like a spring.

[00:21:38]Unlike the osprey or the heron, the anahhinga's feathers are [music] not waterproof, which means it sinks easily enough to dive from the surface and chase fish through the water column, but also means it must spend long stretches holding its wings open in the sun to dry before it can fly again.

[00:22:00]That posture, spread wings, neck outstretched, motionless against the sky, makes it one of the most recognizable silhouettes in the Everglades.

[00:22:17]The Anhinga and the alligator share the sloughs with something prehistoric, enough to make both of them look recent.

[00:22:27]Florida gar are armored in scales so hard and interlocked that early settlers used them to cover plow blades. And they have a swim bladder they can breathe from like a lung, letting them survive in water so oxygen poor that most fish of their size would already be dead.

[00:22:49]Above the gar, working the air over the open slough, a hawk circles with a billshaped for exactly one job.

[00:22:58]The Everglades snail kite eats nothing but [music] apple snails. And that curved bill is designed to reach into the shell and sever the muscle that holds it closed. A level of specialization that means when water levels drop and the snail population crashes, the kite crashes with it.

[00:23:20]The slough holds everything from the [music] apex down. But one predator arrived recently enough that nothing here has had time to learn to fear it.

[00:23:35]Burmese pythons were released into the Everglades by pet owners decades ago, and they have since spread across the southern park in numbers large enough to have removed most of the medium-sized mammals from vast stretches of habitat.

[00:23:48]Raccoon, apossum, [music] and rabbit populations have collapsed in areas where the snakes are dense.

[00:23:59]A large female can produce more than 50 eggs in a single clutch, and the hatchlings are already capable [music] hunters, which means the population grows faster than any current removal effort has managed to reverse.

[00:24:17]Where the freshwater slos [music] drain into the coastal mangroves, the water deepens and clears, and something far larger waits near the roots.

[00:24:31]Goliath grouper can reach over 2 m and weigh more than 300 kg. Ambush hunters that create enough suction to pull in a small shark and whose booming spawning calls are loud enough to be felt by divers nearby.

[00:24:48]Above the waterline, where the ground holds long enough to grow trees, the Everglades rises into hardwood hammocks.

[00:24:55]Islands of [music] dense forests surrounded by open marsh and the first large mammal most visitors will ever see.

[00:25:05]White-tailed deer move between the hammocks and the wet prairie at dawn and dusk. And in the Everglades, they are smaller than their northern relatives. A long-term adaptation [music] to a hot, humid environment where a smaller body loses heat more easily.

[00:25:24]They are the base of the food chain on dry land here. The prey that keeps the Florida panther and the bobcat alive, [music] and the deer know it. A white tail in the hammocks is alert in a way that deer in suburban parks are not.

[00:25:42]The deer move carefully, but the raccoon moves like it owns the place, working the shoreline between the hammock [music] and the marsh with a dexterity that lets it open clams, pull crayfish [music] from their burrows, and rob bird nests with equal efficiency.

[00:26:03]Raccoons in the Everglades are exposed to the same nest sites as nesting wading [music] birds, and they are skilled enough climbers to reach colonies in trees that most mammal [music] predators cannot access.

[00:26:19]They wash their food not out of cleanliness, but because the sensory nerves in their forpaws are more sensitive when wet, effectively turning the act of rinsing into a second examination by touch.

[00:26:37]The raccoon is clever and adaptable, but the largest [music] mammal moving through the hammocks on a given night operates at a different scale.

[00:26:50]Florida black bears are smaller than their [music] northern relatives and spend most of their time in dense cover, eating palmetto berries, fish, carrying, and anything left unprotected. And a bear that learns to associate [music] humans with food almost always ends up dead because of it.

[00:27:11]Where the hammock gives way to the sandy [music] pineup lands along the park's edges, a much smaller animal is doing something the bear never bothers with.

[00:27:22]The gopher tortoise digs burrows up to 9 m long that stay at [music] a nearly constant temperature and humidity year round. And those burrows are used as shelter by more than 300 [music] other species. snakes, frogs, owls, foxes, and insects that could not survive the [music] Florida summer without them.

[00:27:46]The tortoise does not choose its lodges.

[00:27:49]It simply digs and everything else figures the rest out.

[00:27:55]One of those lodges uses the tortoise burrow as a ready-made ambush site.

[00:28:03]The eastern diamondback is the largest venomous snake in North America, emerging at dawn and dusk to hunt along the pine scrub edge. And when cornered, it stands its ground. Rattle up, the venom hemattoxic [music] enough that even a glancing bite requires immediate treatment.

[00:28:27]The rattlesnake takes the rodents and the bobcat takes [music] everything. The rattlesnake cannot. Rabbits, birds, and the occasional deer thorn. Hunted with a patience that ends in a sprint most prey [music] never sees coming.

[00:28:45]They are the most common wild cats in North America and the most invisible, spending their lives in the margins [music] between habitats where neither the open marsh nor the deep hammock can [music] quite account for them.

[00:29:03]Bobcats [music] are fast enough to follow prey into the tree canopy, which almost no other cat their size will attempt. [music] And once they make the climb, they rarely come back empty.

[00:29:18]On open ground, the chase [music] is even shorter. A bobcat closing on a rabbit covers the gap in a few seconds, and the rabbit almost never makes it to cover in time.

[00:29:33]The bobcat's larger relative is one of the most endangered mammals in the country, reduced to fewer than 200 individuals living almost entirely in the southern tip of Florida.

[00:29:49]The Florida panther needs vast home ranges. A male may [music] patrol territory covering hundreds of square kilometers. And the highways, farms, and developments that have carved up the land north of the park mean that young males searching for new territory are frequently killed crossing roads.

[00:30:10]The population has survived [music] largely because of a genetic rescue operation in the 1990s that brought in [music] Texas pumas to prevent inbreeding collapse. And without it, the Florida panther [music] would almost certainly be gone by now.

[00:30:27]In the last light before dark, when the deer move out of the hammock to graze the wet prairie, is when the panther earns its place at the top of the food chain. Here, low through the grass, closing the distance before the deer ever sees it coming.

[00:30:46]where the hammock edge meets a freshwater channel. Something with a very different relationship to the water slides off the bank.

[00:30:58]North American river otterters move between the freshwater marsh, the hammock streams, [music] and the coastal mangroves without any obvious preference, eating fish, crayfish, frogs, and occasionally small turtles.

[00:31:11]And doing all of it with an energy that makes [music] the alligator look catatonic.

[00:31:20]They are highly vocal and highly social, and the sounds they make while feeding and playing carry clearly across quiet water. One of the few ways to know an otter is nearby before you see it.

[00:31:38]At the very edge of the hammock, where the grass meets the water, the smallest mammal in this chapter has a survival strategy that no other rabbit [music] in North America uses regularly.

[00:31:54]The marsh rabbit lives [music] so close to the water that its fur stays damp for most of its life, spending its days in the marsh grass and its [music] nights in the channels. A routine that makes it invisible to most people who have never thought to look for a rabbit in the water.

[00:32:13]When the bobcat or the panther closes in, [music] the marsh rabbit goes where neither cat will follow into the water, crossing open channels between grass islands with its ears flat and its body [music] barely breaking the surface, using the Everglades itself as its escape route.

[00:32:36]Rise above the hammock canopy and the Everglades opens [music] into something vast. miles of saw grass and open water laid out in every [music] direction. And above it all, the largest bird of prey most people in North America will ever see in the wild.

[00:32:57]Bald eagles nest in the Everglades year round and build some of the largest nests of any bird on Earth, returning to the same tree for decades and adding to the structure each year until it weighs more than a ton.

[00:33:15]They are fish hunters primarily, hitting the surface at speed and locking their talons into prey with a grip strong enough to carry a fish several times the weight a person could hold at arms length.

[00:33:30]But the eagle is also a thief and a scavenger. And where a carcass draws a crowd, it is usually the bald eagle that controls the table with ravens and vultures [music] working the edges, stealing what they can between the eagle's wing beats.

[00:33:50]The eagle dominates by mass, but there is a bird above the Everglades in spring that makes it look [music] clumsy.

[00:34:01]The swallowtailed [music] kite arrives from South America each year and spends its time here in almost continuous flight, catching insects and small lizards on the wing, [music] drinking by skimming the surface without landing, and drinking and bathing by flying through rain. It lands so rarely that finding one perched is genuinely unusual.

[00:34:25]Above the tree line where the short-tailed hawk works, the prey is other birds.

[00:34:32]The short-tailed [music] hawk is an aerial specialist that hunts almost exclusively on the wing, stooping on small birds flushed from the canopy edge. And the Everglades is one of the few places in the United States [music] where it breeds. Most of the world population winters further south.

[00:34:55]It comes in two color morphs, dark and light, [music] and the two forms hunt the same territory and occasionally nest side by side, which took decades to figure out because early observers [music] thought they were looking at two different species.

[00:35:13]down from the open sky inside the mangrove canopy where the light barely reaches. A much less conspicuous bird hunts in near silence.

[00:35:25]The mangrove cuckoo is one of the hardest birds to see in Florida. It sits motionless for long stretches [music] and moves through dense cover so slowly that it barely disturbs a branch. And despite living in one of the most visited national parks in the country, it goes largely undetected. [music] It specializes in hairy caterpillars that most birds avoid because the hairs irritate the gut lining, swallowing them whole and periodically shedding the stomach lining to clear the accumulated bristles.

[00:36:04]The mangrove cuckoo works the shadows, but the white crown pigeon moves in the open, flying between the Florida Keys and the Everglades mainland to feed on the fruit of poison wood and gumbo limbo trees that nothing else wants.

[00:36:23]>> [music] >> It can digest fruit that is toxic [music] to most birds, which gives it access to food sources with almost no competition. But it makes the bird dependent on exactly the kind of old growth hammock that has been cleared for development across most of its Florida range. [music] >> [music] >> The Everglades now holds the largest remaining nesting colony in the United States, which means [music] the park is carrying a species that has nowhere else left to go in this country.

[00:37:03][music] Where the pigeon moves between trees, the smooth build Annie barely moves at all.

[00:37:15]It is a communal bird that roosts, nests, [music] and incubates eggs in groups. Multiple females laying in the same nest, multiple adults [music] sharing the warmth. And it has spent the last several decades contracting its range until the Everglades became the only place in the [music] United States. It reliably survives.

[00:37:39]High in the hammock canopy, moving millimeter by millimeter across the bark [music] of gumbo limbo and mahogany trees, the most visually improbable animal in the Everglades carries its house on its back [music] in colors that should not exist in a temperate forest.

[00:38:01]Florida tree snails come in more than 50 distinct [music] color banding patterns.

[00:38:06]Each population isolated to a single hammock island [music] and found nowhere else on Earth. Pink and white in one hammock, orange and chocolate in the next, [music] and the color of every shell in between.

[00:38:22]The isolation of the Hammock Islands has been going on long enough that the populations have diverged visually, but not enough to [music] stop interbreeding when they meet, which puts them in an evolutionary gray zone [music] that taxonomists have been arguing about for 100 years.

[00:38:43]Below [music] the canopy, below the waterline, at the margins of places most people never walk, the Everglades holds animals so rarely seen that their current status is mostly guest work.

[00:38:59]The Everglades mink is a subspecies found nowhere outside the southern Florida marshes, and it has been documented so infrequently that basic facts about its population size are still uncertain. A small, fast, semi-aquatic predator in [music] a wetland with very few roads and even fewer researchers watching.

[00:39:21]Out on the open mile prairies west of Flamingo, where the ground stays barely above water for most of the year, a small brown bird has been reduced to a handful of isolated populations by 50 years of water management decisions that flooded its nesting habitat at the wrong time of year.

[00:39:42]The Cape Sable seaside sparrow exists nowhere else on Earth, [music] and the debates over how much water to send, where, and when are partly debates about whether this bird survives at all. Every major water release decision in the southern Everglades has a direct line to the sparrow's nest survival.

[00:40:04]Further north along the keys in the last fragments [music] of tropical hardwood hammock, a rat that most people have never heard of is holding on in a habitat that has been losing ground for decades.

[00:40:21]The key woodrat builds elaborate stick nests in hammock understory and eats the seeds and fungi of the forest floor.

[00:40:29]Living in a patch of habitat so small and so fragmented that a single hurricane has the potential to eliminate populations entirely.

[00:40:41]It shares its remaining hammock with a handful of other species found nowhere else. All of them in the same situation.

[00:40:49]Just enough habitat left to survive. Not quite enough to be secure.

[00:40:58]In the same hammocks for a few weeks each spring, a butterfly that was declared extinct and then rediscovered glides between the torchwood and wild lime trees it cannot breed without.

[00:41:12]The Shia's swallow tail is one of the rarest butterflies in North America, and its survival depends on the same old growth hammock that the white crowned pigeon [music] and the woodrat need. a triangle of dependence connecting a bird, a mammal, and an insect on a strip of limestone islands that the ocean is slowly reclaiming.

[00:41:36]Smaller and rarer still, the Miami blue butterfly was presumed extinct for nearly a decade [music] before a tiny population was found in the Florida Keys.

[00:41:49]It is now one of the most endangered butterflies in the world, hanging on in a pocket of coastal [music] scrub so small it can be crossed on foot in a few minutes. Dependent on specific host plants that grow in the kind of habitat that developers have spent a century eliminating.

[00:42:12]Back in the marsh where the open water meets the sawrass, something the size of a large rat is doing. What the manity does at enormous scale, but in miniature.

[00:42:25]The roundtailed muskrat grazes on aquatic vegetation [music] in the freshwater marshes of the Everglades and builds floating platforms of plant material just above the water line. Small enough to overlook, numerous enough to be found across almost every open water marsh in the system when [music] conditions are right.

[00:42:50]And at the very bottom of the chain, [music] smaller than a thumbnail and louder than its size suggests, the little grass frog holds the grass [music] stems over every open marsh in the Everglades.

[00:43:05]It is the smallest frog in North America, and it calls at a pitch so high that older observers sometimes cannot hear it at all. a thin peeping from the grass that means the marsh is still healthy enough to support [music] the bottom of the food web. The first thing that disappears when the water chemistry changes and the last thing people think to check.

[00:43:30]The water that moves through the Everglades takes months to travel from Lake Okichchobee to the sea, slowing through saw grass and slough and mangrove [music] until it finally reaches the Gulf. And everything in this film lives somewhere along that path.

[00:43:49]The alligator holds the center of it.

[00:43:54]The panther walks its edge.

[00:43:58]And the sparrow nests in the margins where the water [music] level is decided by a committee sitting in an office building 200 km away.

[00:44:08]The dry season will come again.

[00:44:12]The sloughs will shrink and the gator holes will fill with everything that [music] has nowhere else to go.

[00:44:22]The same cycle that has run here for [music] thousands of years. Running now on borrowed time and a narrowing margin.

[00:44:32]This is Everglades National Park, a land of untamed beauty and wildlife at every turn. Now, if you don't want to miss the most extraordinary wildlife of the Congo, check out this video.