The Eternal Goose
The eternal goose, Anser invictus, is a close cousin of the bar-headed goose. Breeding annually in the high plateaus of the Himalaya, the birds spend most of the year flying at extremely high altitudes. Several eye-witnesses have reported sightings of the geese from commercial airliners from all over the world.
Scientists have been interested in the eternal goose for a long time, especially the mechanisms that allow it to fly at heights of up to 10'000 meters (~33'000 feet), and the selective pressures that have pushed them to choose this lifestyle. In recent years, the geese have been tracked year round, and the data obtained showed that the animals were even more amazing than thought at first.
If before it was believed that 10'000 meters was their maximum altitude, it has now been shown that it is in fact their cruising altitude. Indeed, after their short reproductive period, the animals will fly off, quickly reaching their cruising altitude, at which they will remain until it is time to breed again.
Analysis of flight routes, as well as wind patterns, show that the geese, once they reach their desired height, barely have to make any effort at all. The wind currents will simply let them glide along, until, nine months later, they once again arrive at their breeding grounds. While the birds are at high altitude, they reduce their metabolism to a minimum, consuming almost no energy at all. The cold of the upper reaches of the atmosphere, combined with a special protein that prevents ice-crystals from forming, helps prevent cellular damage. And of course, the high altitude makes sure that they are safe from most, if not all, predators.
Due to the fact that they spend most of their time in a form of suspended hibernation, eternal geese are among the most long-lived animals on the planet. How long exactly they can live has not yet been determined, because since the studies begun, over sixty years ago, most of the animals that survived their first year have stayed alive.
Today, however, the geese face a growing threat from climate change. The changes in temperatures provoked by global warming affect the air currents, and leave the geese either caught up in the gales, and unable to descend at their destination, or stranded in unfamiliar lands at irregular intervals. Wether this will cause the extinction of the species, or allow them to colonize new habitats, remains to be seen.
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