Eagles: The Kings of the Sky | Free Documentary Nature

The eagle, a heraldic bird, the epitome of the majestic, whether in Alaska or the Dolomites. Eagles are simply the sovereigns of the air. Alaska, the most northerly of the United States, is famous for its eagles. And yet that bird became the symbol for the whole of the United States, the bald eagle. Nowhere are there as many of these majestic creatures as on the Chilkat River, right in the south of Alaska. The river is bounded by the Takshanuk Mountains, that also feed it regularly through their many glaciers. In the summer, this river acts like a magnet to attract brown bears. They look as if they're waiting for something. The mother bear and her cubs are afraid of the males. But he is after something completely different. A different member of the group is more fortunate. Salmon are the reason why they have all come to the river, whether they are large or small. Waiting for the fish to arrive one after another in the breeding grounds can be a tedious business. The younger generation has found an alternative pastime. But before they're able to catch their own salmon, they'll be a year older. Even experienced bears' salmon fishing skills are overshadowed by those of the bald eagles. And even herbivores, such as the moose, benefit from the salmon in a roundabout way. As many as four times in a year, chum salmon migrate up the Chilkat River. After spawning, the fish will die and are then even easier prey for the eagles and bears. Their remains fertilise the soil, which helps the lush vegetation to flourish. Besides the bears and eagles, the Chilkat has other attractions to offer. And they also act as landscape designers. Canadian beavers. They're larger than their European cousins. And there is even discussion about whether or not they are a species in their own right. Thanks to their powerful flat tails and webbed feet, they're perfectly adapted to a life in and around the water. The entrances to their lodges are always underwater to provide protection. To make sure the entrances remain underwater, beavers build the dams they're famous for. Kids stay with their parents for two years before they set off in search of a home of their own. But the main attraction along the rivers is the bald eagles that also rear their young here. With a wingspan of up to two and a half metres, they're among the most impressive of the eagles. As many as 400 pairs live in Chilkat State Park all year round. And in 2017, 80 eries were counted. The young remain in the erie for nearly a quarter of a year. However, by September at the latest, they must leave the nest because Alaska's summer is a short one. The northern lights against the clear, starry sky are the harbinger of winter. The countryside will often change abruptly overnight and temperatures fall to below minus 20 degrees Celsius. Mist provides a mystic touch over the landscape, an unusual feature where the temperatures generally cause all water of any kind to freeze. This is equally puzzling. In some places, increasing numbers of eagles are congregating. What do they expect to find here in this snowy wilderness? Oddly enough, the river is not completely frozen over. This is the reason why mist rises above the water, which is now warmer than the surrounding land. And the eagles? They are waiting, just as they did in the summer together with the bears. The bears have started their hibernation phase, otherwise they would surely be here too. The ice sheet has a secret. There are salmon migrating under it. This is the fourth and final salmon migration of the year, and nowhere else does it take place so late in the year. The fish migrate around 40 kilometres upstream as far as the ice-free regions. As if by magic, the river meanders completely free of ice for around 10 kilometres through the surrounding frozen countryside. The answer to the mystery lies in the volcanic activity in the region. Hot springs feed various small tributaries of the Chilkat. Sources of life. But not for the salmon. The warm water does mean that they can spawn here, but for them, the Chilkat is the river of death, as it's often referred to. There are thousands of dead fish floating in the water. As is true after every salmon run, the exhausted salmon will die after spawning. However, for this young eagle, the combination of ice-free water and dead fish means only one thing. Life. And that does not only apply to him. 3,000 to 4,500 eagles gather along the Chilkat at this time every year, unparalleled anywhere else in the world. The visitors outnumber the permanent residents by three to one. Many come from regions hundreds of kilometres away, and some will even travel 2,000 kilometres from the state of Washington. They're all here because of the salmon, dead or alive. With such an abundance to choose from, they can afford to pick out the finest specimens. Their claws are deadly weapons that hardly anything will escape from, and the mighty beak is an excellent filleting tool. The brown head and dark beak identify this one as a young bird, and the brownish-white spotted underbody means it's at least two years old. Nowhere other than by the Chilkat does such a young bird have such a good chance of surviving the winter. Many fledgerings elsewhere do not survive their first winter. Eagles do not sport the yellow beak and white head until they are six years old. Exhausting flights in search of prey are not required here. The older eagles benefit most. The pecking order is clearly defined. Fledgerings give way to their elders. The salmon's spawning season is nearing its close. The last survivors are completely exhausted. About five to seven years ago, these salmon hatched here and then swam down the Chilkat into the Pacific. There they grew until it was time for them to tackle the long, tiring journey back to their nursery. Under the ice sheet, they were safe. But here there are eagles everywhere. Salmon that get caught too early are unable to fulfil the object of their travels, spawning. And those that do spawn are still bound to die here. Throughout the entire migration, the fish have gone without food. Their fate is sealed. A fully grown salmon can weigh up to four kilos, almost as much as the bald eagle itself. Dragging the fish from the water is a feat of strength even for North America's second largest bird of prey. Only the condor is larger than the eagle. And there are some cheeky scavengers that are not frightened off at all by the imposing eagles. Wily ravens will always find a suitable moment to hop in and pinch something. Bald eagles are actually more akin to ravens than they may appear at first sight. They too are carrion scavengers, although the bald eagle is also a skilled hunter and fisher. In the winter, though, this activity burns up large amounts of energy. So what could be more tempting than to feed off carrion? There's hardly any other location where carrion is offered in such abundance at this time of year. These days of gluttony are numbered. The spawning period is over and the number of salmon depleted. There's fierce competition over the last dead fish. A young eagle makes an audacious attack on one of the elder ones, but fails. It's often the raven that benefits from the quarrel. A mere bone is hardly a replacement. Some birds of prey can indeed eat and digest bones, but the bald eagle is not one of them. These winter visitors will soon be leaving the Chilkat. The binge is coming to an end, and yet, come spring, the melting snow and ice will release many a deep-frozen fish supper that will allow the bald eagle to tuck in once again as the most impressive resident of this unique river that provides it with food and life nearly all year round. Many thousands of kilometres away, there's a mountainous country that can certainly claim to be on a par with the Alaskan Tashanuk Mountains in many respects, the Dolomites, a range of mountains in the south-east of the Alps. This is the home of the golden eagle, Europe's largest bird of prey, and of its prey, marmots... and chamois. In the Poes Geisler Nature Reserve in south Tyrol, the eagles begin breeding in mid-March, which coincides with the marmots leaving their burrows after several months of hibernation. Soon after they wake up, they begin their mating rituals. After all, they have to make sure their cubs are large enough and strong enough before the next winter begins. They keep a constant lookout. The eagle is their greatest enemy. Marmots make up 60% of its food requirements. But ptarmigan are also on its list of favourites. These are still well camouflaged. To make sure their camouflage continues to work after the snow has melted, they will soon acquire brown plumage. Slow movements to avoid attracting attention and the watchful eye on the skies help to prolong individual survival. Only the males sport red eyebrows. The females are less obviously colourful. When the eagle is highlighted by the rays of the sun, it's easy to see why it's called the golden eagle. Its eerie is at an altitude of 2,000 metres in the north-facing wall of the geyser group. The female has laid two eggs. A typical clutch is from one to three eggs. While the female broods, the male goes hunting and supplies his mate with food. However, some sightings claim that the partners take it in turn to brood. As they glide on the lookout for prey or carrion, these birds make use of thermal upwinds. The female's wingspan is over 2.20 metres, but the males are smaller. The male alpine ibex, which is the other wild goat species in the Alps alongside the chamois, need not fear the eagle. Even the smaller females are too large for that bird of prey, but things will soon be different when the next kids are born. The females tend to live separately from the males, and they only come together in the winter during the mating period. The safest places for the goats that are very sure-footed are the steep slopes, which in the Dolomites are plentiful, where the eagles have great difficulty attacking. One and a half months later, a single eagle chick hatches. Since the eggs are laid one after the other, they do not all hatch at the same time, but it looks here as if the second egg was not fertilised. The male delivers the prey to the nest for the female and chick and then returns to the mountains for more. It's the duty of the female to tear the food into bite-size pieces for the chick. Not always an easy task. Getting the size right requires practice and a good eye. When a six-kilo mother and a featherweight chick share the same cramped space, the mother has to be very careful how she manoeuvres. At regular intervals, the mother will warm the chick, but as it grows, she will be able to leave the nest more frequently to join in the hunt for food. In marmot families, some of the members are set to keep guard. Vigilance is particularly important because there are now youngsters around too. The pups are already large enough to go and explore their surroundings. At no other time in their life are they so at risk. While they are engrossed in their playful fights, they only have eyes and ears for each other. The watchman has detected the enemy. But they check first to see if flight is the best option. After all, running uses up valuable energy. The older animals now know it's time to move. In the meantime, the chick in the erie is busy with itself. But then suddenly it's faced with a most unusual apparition. Like the phoenix rising from the ashes, a much-maltreated marmot appears right up here in the wall. There can only be one explanation. Presumably, it had been caught and plucked by one of the parents and then deposited in the nest. It has now recovered from its comatose state. But the plucky animal does not intend to give up without a fight. The fledgling defends itself bravely. Perhaps the parents will hear the clamour and rush back to help. Finally, the chick comes out of hiding. The marmot's strength has obviously been sapped. One thing is for sure, there is no escape from the erie. A dramatic encounter that has probably never been filmed before. Spring arrives late and quickly transitions into early summer, the most beautiful time on the mountain meadows. The chamois now also have kids. Within a very short time, they are remarkably sure-footed. For mountain goats, this is the best time of the year, with abundant supplies of juicy food. The bond with the mother is still very close, but the babies grow quickly. They're not yet large enough to be safe from the eagle's talons. Strolling around alone can be a dangerous activity. The eagle chick is now seven weeks old and developing well. The flight and covert feathers are already showing through the downy coat. The chick is able to serve itself now. Despite its sturdy-looking legs, standing up is still a wobbly affair. A fall from this height would be fatal. The mother is now bringing larger prey. This chamois kid obviously didn't get into a safe place in time. Being fed is still the preferable option at this age and the most effective. The parents will feed their chick around 25 kilograms of meat while it's still a nestling. Hardly surprising that they have to keep going out hunting for more. The short summer is drawing to a close. The eaglet is now two and a half months old. And is vigorously exercising its flight muscles. But some time will pass before it can hunt on its own. The father brings home a chamois kid. These impressive birds can carry up to 15 kilograms, more than double their own weight. The young eaglet will soon leave the Erie, even though the parents will continue to feed it for some weeks. Golden eagles have conquered almost the entire Northern Hemisphere, from the west coast of North America to the east coast of China. But the hunting grounds belonging to this young eagle must be among the most beautiful. The Dolomites. As majestic as the sovereigns of the air.