"[♪]" "[David Suzuki]:" "The west of Canada contains the most diverse range of habitats found anywhere in the country." "[♪]" "It's a place of extremes." "The rugged Rocky Mountains form a vast barrier that sets the west apart from the rest of the country." "Rain pours off the mountains, forming waterfalls and raging torrents, and flows west into the deep inlets of the Pacific Coast." "These waters, both fresh and salt, support the largest temperate rainforest on the planet." "The region is home to the greatest variety of animals in all of Canada." "[♪]" "[Bear growls]" "[Wolf howls]" "The land appears rugged and untamed." "But it's not pure wilderness." "Human hands have influenced it more than we might realize." "The source of the West's riches lies in the sea." "Pacific salmon have been coming here for some six million years." "They were here before the beginning of the last ice age and long before the arrival of human beings." "Every summer, hundreds of millions make one of the planet's greatest migrations, from deep in the Pacific Ocean swimming far inland to spawn in the exact spot where they themselves were hatched." "Their journey defines the entire West." "The West Coast rises abruptly from the deep ocean, and its nutrient-rich waters attract animals of all kinds." "Marine mammals like killer whales come here and intercept the migrating salmon." "This is one of the richest coastlines in the world." "But there is another reason why life proliferates here..." "These flat-bottomed silty coves may seem unremarkable, but they are not entirely natural." "We now know that ancient people began to create them thousands of years ago to encourage one particular animal to flourish." "The clues lie buried." "But crows, highly intelligent birds, dig them out." "Clams need this silty substrate to live in, but they can't escape the crows." "Digging them out is only half the job." "The birds then have to get rid of the shell, and they know just how to do that." "[Crack]" "At low tide, they are easy to spot because they squirt water through their siphons." "That's how they breathe, eat, and eliminate waste." "We have only recently come to understand why the clams are here in such numbers." "Recent aerial surveys carried out at the very lowest tide showed repeated patterns of rocks." "But because these rocks are usually under water, no scientist had paid any attention to them." "Only when the First Nationss People living on the coast were questioned did the answer become clear." "Their ancestors had been farming the sea." "They built a wall which created an artificial cove." "Once silt accumulated behind it, the clams had a huge area in which to breed and proliferate." "At the lowest tides, the people reaped the rewards... collecting the clams, but also the whelks and seaweed growing on the rocks." "The first peoples along the coast had perfected sophisticated ways of cultivating wild food in their environment." "Although the settlements where people lived for thousands of years are gone, the walls they built still serve their purpose." "And it's not only humans that benefit from them." "Raccoons have particularly sensitive and dextrous paws equipped with thin hairs that enable them to sense prey before they actually touch it." "Mink, on the other hand, rely on their very sharp eyes to detect their prey." "It's easy to forget that the landscape of this coast is not all natural." "It's physically different than it would have been without humans." "There are almost 300 clam beds in this small area of coastline." "These human-built features have undoubtedly increased the abundance and diversity of Canada's West Coast." "People have been here on this coast for a very long time." "At the end of the last ice age, this was the main human migration route from Siberia into the continent." "People came south by skirting along this coast." "Here, there were fish, mammals, and plants to eat..." "And easier travelling conditions than across the ice-covered interior." "And the salmon, swimming up the rivers, would have been an easy target." "As they wait in the estuaries, they stop eating, and their bodies begin to deteriorate." "As salmon leave the saltwater, their bodies undergo major changes to get ready for spawning." "They've got a limited time to reach their spawning ground, and some of them have a long way to go." "And there are many dangers ahead." "[Wolf howl echoes]" "Rainforest wolves prowl along coastal inlets." "These are rich hunting grounds." "Wolves are mostly nocturnal, so it's rare to see them out in the open in broad daylight." "A pack has been attracted by the prospect of feasting on the salmon in this intertidal zone." "At low tide, there's less water, which makes the task easier." "It seems as if the wolves are killing more than they can ever eat." "A single pack can land more than 200 salmon in a few hours." "But there's a good reason for them to do so... the wolves won't eat the flesh of salmon, as it may contain parasites that can kill them." "But they do like to eat the heads." "The brains are very rich, and free of the deadly parasite." "But the most nutritious part of the salmon is the skin, rich in fat, and this is hard to get at without eating the flesh." "So the wolves let other animals prepare it for them." "They deliberately leave their catch on the side of the river in plain sight of the scavengers." "The ravens and eagles then come in for easy pickings." "They eat the fresh flesh, but leave behind the skin and bones." "When the remains are sufficiently decomposed, the wolves come back and eat the healthy leftovers." "Wherever they go, the salmon nourish the wildlife on the coast." "There are more than 200 species in these forests that feed on the salmon." "[Wolf howls]" "[Howling continues]" "Once they are past the wolves, they still have a long journey ahead of them." "Salmon have an amazing sense of smell." "They are able to detect one particle in a billion that may be characteristic of the river where they hatched." "As they head upstream, the current gets stronger." "But with some sections, the river becomes so fast and steep they can no longer swim against it." "They have to leave the water to get through." "With special cameras, this action is slowed down 80 times its regular speed." "At this speed, it's evident how they use their tails as rudders to help keep them upright and on track." "[♪]" "These jumps are the equivalent of a human leaping over a four-storey building." "The precision of their jumps and the exact point of re-entry can make the difference between life and death here." "But if they are to reach their spawning grounds, they have to get through." "[♪]" "Salmon are heading upstream to spawn at the exact point where they themselves were hatched, and it's a very perilous journey." "Bald Eagles nest near the rivers, waiting for the salmon." "[♪]" "They have very sharp eyesight..." "And powerful talons." "There are other predators here too." "Some 150,000 Black bears live in British Columbia alone." "Huge numbers of them head for the rivers to intercept the salmon." "Like humans, bears have a very varied diet." "During the rest of the year, they are mostly vegetarian." "This is the only time they can get high-protein food." "But the salmon, at this stage of their journey, are still full of energy, and they are not easy to catch." "[♪]" "Eventually, the bear's persistence pays off." "[♪]" "When they catch a particularly big salmon, bears often take it into the forest to eat it under cover." "In British Columbia, bears and scavengers carry thousands of tons of salmon into the forest each year." "When there are lots of salmon available, bears usually only eat about a quarter of a fish, selecting the fatty parts." "The rest of the body and the bones rot away and nourish the trees..." "And they grow into some of the tallest in the world." "Salmon carcasses make the best fertilizer, providing up to 80% of the marine-based nitrogen in these forests." "Spruce trees here can be three times larger than those growing close to rivers where there are no salmon." "There are six different species of Pacific salmon, including Steelhead trout, that run inland at different times of the year." "This one is the sockeye." "The survivors have reached the spawning grounds." "The females make nests in the gravel to lay their eggs." "The males, swimming alongside, fertilize them." "[♪]" "Some of the salmon used to get a helping hand from the locals." "The Heiltsuk, who call themselves the Salmon People, know the salmon's spawning behaviour very well and had remarkable ways of helping them." "As soon as the eggs were laid and fertilized, they were gathered and carefully placed in cedar bentwood boxes lined with moss to keep them moist." "They were then taken away and put in a different free-running river." "This helped populate new streams." "And the effects were long lasting, as salmon always return to the place where they hatched to lay their eggs." "So new groups of salmon were created that fed communities, both humans and wildlife, for generations to come." "This great forested landscape of huge coniferous trees is living proof of how successful they were." "The world's largest temperate rainforest still flourishes largely due to the nutrients provided by returning salmon." "[♪]" "Conditions in the mountains inland are tougher than the coastal forests." "It's harder to get around." "There is less plant life, less water, and so fewer animals." "But the wildlife that lives here has adapted to these extreme conditions." "Dall sheep like tall, steep mountain peaks where they feel safe." "But they have to come down to lower altitudes to eat." "And here, predators await them." "The secretive and solitary lynx is rarely seen in the day." "But grizzly bears are bolder." "[♪]" "[♪]" "The adult sheep are too nimble to be caught here..." "During the spring lambing season, the newborns are particularly vulnerable and have to learn quickly about how to move up and down the mountain." "[♪]" "And they must keep close to mom, as there's danger everywhere." "But their greatest threat is hardest to spot." "Golden Eagles can spot a newborn lamb from two kilometres away." "They can pick up more than their own body weight and fly off with it in their talons." "But the lambs grow fast." "Within a few weeks, they will be too heavy for the eagles to lift." "The lambs will be safe as long as they stay with their mothers." "But the swooping eagle tries to separate them." "[Guttural-sounding "baas"]" "Away from the main herd, a lamb is in real danger." "[Lamb squealing]" "[Lamb squeals echo]" "[♪]" "Surviving in the mountains requires special skills." "The European settlers called the rockies the "impenetrable peaks"" "and needed the expertise of the local people to guide them through." "Many of the First Nations of British Columbia were completely at home in the western mountains." "Entire families would trek for weeks to get through these ranges to reach the coast." "There, they traded furs and skins for fish oil and seaweed." "[♪]" "While humans could move out of the mountains in winter, the wildlife here has to adapt to the changing conditions." "Bighorn sheep head to high, remote, windswept areas." "Here, they can easily scrape away snow and ice to expose buried grasses." "Bighorn sheep often split into gender groups... females with shorter horns, and males with large, curled horns." "These horns can weigh 15 kilograms and have growth rings from which you can determine the age of the animal, rather like rings in the trunk of a tree." "Those with the largest horns have the highest status." "Having fed all summer, the rams are in peak condition." "Inhaling pheromones in a female's urine, they can determine her breeding readiness." "But first, they have to sort out mating rights." "They start with playground-like taunts." "With kicks and shoves, the weaker rams are tested, and their social rank determined." "[♪]" "At last, one big male peels off, and that lays the gauntlet down to all the others." "Anyone who feels strong enough now needs to fight to prove it." "[♪]" "They charge at 30 kilometres an hour, and the impact is titanic." "Skulls are double-layered to protect their brains." "These clashes can go on for a full 24 hours." "The winner now has the mating rights for the entire herd." "The lambs will be born in spring, timed to coincide with the arrival of the lush new growth of grass." "But before then, times will be hard." "[♪]" "[Wind whistles]" "In the west of Canada, temperatures are falling, and conditions are about to get much tougher." "Summer's rich bounty has come to an end." "But one last wildlife spectacle will play out before the full force of winter arrives, and it happens in a most unlikely place." "This is the Northern Yukon Territory in november, near the Arctic Circle." "It is extremely unusual to see trees of this size at such northern latitudes." "The secret can be found in this river." "It has an underground spring that keeps it from freezing." "The whole area is transformed as a result." "This late-season open water supports a salmon spawning migration." "And as in the temperate rainforest thousands of kilometres further south, salmon carcasses allow these spruce trees to flourish." "These chum salmon have travelled thousands of kilometres to get here." "For every thousand or so eggs laid here, only one adult salmon will return." "They are now at death's door and easy pickings for any predator that can get here so late in the year." "[♪]" "[♪]" "Grizzly bears have only a limited period to eat." "Even though it looks like an easy feast, this is actually a desperate struggle for survival." "They need to devour huge amounts of salmon to ensure that they'll get through the long, cold, northern winter." "They may eat 40 kilograms of fish, then gain up to two kilograms in body weight in a single day." "Any salmon will do, alive or dead." "In a matter of weeks on this rich, fatty diet, the shape of the bears is completely transformed." "Grizzlies stay out late here, braving the -20 degree temperatures." "Ice forms on their thick, insulated coats." "The Vuntut Gwitchin First Nations used to call them "Armour Bears,"" "as they thought arrows could never pierce the thick shards of ice." "Grizzlies are usually solitary." "But around here, 40 bears gather quite closely together to share the feast." "There is a strict hierarchy here, based not only on size, but temperament." "[Bear growling]" "This is a unique event." "Never before have grizzly bears been shown thriving on the Arctic Circle, eating salmon that spent most of their lives far away in the Pacific Ocean." "But there is an additional reason for this extraordinary sight." "The Vuntut Gwitchin First Nations group here have always revered this place and protected it." "They agreed among themselves that no one should be allowed to exploit or destroy it." "They recognized it as a place where food could always be found, even in the depths of winter." "Today, it's a territorial park, and the grizzlies are left in peace." "From the Arctic to the rainforest, this part of Canada is filled with astonishing wildlife spectacles." "It is this co-existence and interdependence of animals, people, and the landscape that makes this place the true wild west."