Flying High Without Oxygen

Let's start by over-stating some basics. First, we depend on oxygen to survive. Down around sea level, the pressure is fine and we can get what we need. You go up the mountains, the air is thinner. Death Valley is below sea level, so don't be in a great hurry to go from there to Denver, the "Mile High City". (Baseball players don't always cotton to playing up there.) Mountain climbers need to take extra precautions, as do pilots. (For that matter, your big ol' jet airliner trip was in a pressurized cabin.) Fighter pilots have oxygen masks. Taking your dog with you on a bombing mission can be bad news if you're both unprepared; going up too high too fast, or just too high at all, can be disastrous.

Attaining high altitudes can cause difficulty for many creatures, and even be lethal. So, how do birds comfortably survive altitudes that we can't handle?
Whitney Smith, the 53rd Wing honorary commander
US Air Force photo / Sara Vidoni
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So how is it that birds can easily fly at altitudes that would be lethal to humans? Evolutionary explanations are obviously pure guesswork, and the best (and obvious) explanation is that birds are designed by their Creator with hearts and respiratory systems to deal with the situations.
If dogs were meant to fly, they would have bodies designed for it. Flying at altitudes so high that the lack of oxygen is a serious problem requires bodies specifically equipped for breathing thin air. This need is illustrated by an amazing German Shepherd named Antis that flew in combat missions during World War II at altitudes of up to 16,000 feet. How did this dog survive flying in oxygen-starved altitudes?
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What about high-flying birds that have no such oxygen mask? How can they survive elevations of 15,000 feet and sometimes higher without a supplemental source of oxygen? Many bird migrations occur at extremely high elevations: 21,000 feet for the mallard duck, 27,000 feet for swans, even 36,000 feet for vultures!
To read the interesting story about Antis as well as information about bird design, click on "High-Altitude Flying Is for the Birds".