In the far north-west of the American continent stretches a land some one and a half million square kilometres in size.
In the far north-west of the American continent stretches a land some one and a half million square kilometres in size. Only six hundred thousand people inhabit this region where the frozen tundra, the coniferous forests and the mountains dominate a landscape which, in some places, has never been trodden by man.
The start of the melt announces the resurgence of life in Alaska. With the vegetation, food returns, and the largest of Alaska's land carnivores, the grizzly bear, awakes from its winter sleep. The grizzly bear belongs to the same species as the European bear, but its better diet enables it to grow much bigger. A Pyrenean bear weighs around 300 kilos and stands two metres tall, while on Kodiak island some bears can weigh almost 1,000 kilos and measure 3 metres. The grizzlies are solitary animals, and at the start of spring hunger makes them even more dangerous. In times of hunger the adult bears are capable of killing and eating young of their own species.
All of them are waiting for the salmon to arrive, their only hope in this cold, hostile land. Each year thousands of salmon return to the rivers where they were born, providing the local wildlife with the food they need to build up the reserves necessary to survive the long, harsh winter. They are manna from the sea, the reserves of protein and fat everyone is waiting for. The salmon, quite simply, are life.
The salmon have finally reached the land they originally came from, but their odyssey has just begun. Now, they have to face seagulls, eagles, otters, and above all the great predator of Alaska, the largest land carnivore in the world the grizzly bear.
The indefatigable salmon again set off on their journey home. But their bodies must undergo major transformations, sexual glands have been developed and prevent them from eating. They will have to conquer the rapids, leap up waterfalls and escape from their predators without eating a single thing.
at this time of summer, fishing has become almost a game, and they don't even eat the majority of those they catch. Along the riverbanks float hundreds of dying salmon, and the bodies of those who were unable to survive this demanding test.
The salmon also benefit from this natural selection. The fact this test is so demanding means only the fittest will make it to the end. Moreover, the number of salmon that come to these coasts every year is such that, if they all reached their final destination, the rivers would be saturated. The last to arrive destroy eggs previously laid by others, and prepare their own nests right there. The population needs to be controlled, and that is precisely the role the predators perform.
Finally, after many hardships, the salmon make it to their respective spawning grounds. After choosing a suitable place, the salmon prepare their nests.