The Bird that climbed Everest

You may not have heard of them, in fact I very much doubt you have, but I just want to say that the bar-headed goose is an absolute marvel of nature. This goose can fly over Mount Everest. That means they fly almost 9000 metres up in the air. The bar-headed goose (Anser indicus). Image credit: Noel Reynolds ( Wikimedia Commons ) "Whoop-de-doo" you might think. After all, they can fly so it shouldn’t be that hard. Wrong! Flying is already tough enough as it is. I mean I can’t do it, can you? (and no planes do not count). Flying is an incredibly tiring activity under normal circumstances, but this goose faces further adversity from chilly winds and oxygen starvation. The only question now is 'how do they do it?' The problem A big problem with flying as high as the bar-headed goose does is that the air is very thin. But what does this even mean? Mount Everest. Image credit: Ocrambo ( Wikimedia Commons ) I'd like you to imagi...