2 ms·

Is there another 'reason' they fly so high(predator avoidance, optimum energy usage, etc), apart from what the article mentions about the Himalayas shooting up

• jacquesm 7y ago
  The same reason why jets fly that high? After all, rarefied air offers less resistance and if there is one thing that birds are adept at it is figuring out how to more efficiently use the air. It would be interesting to see if they only do this when the jetstream is to their advantage or also when it is neutral or even disadvantageous.
  • tim333 7y ago
    The fact that they hug the terrain and go down when they can implies they prefer it lower and only climb that high to clear the mountains. For planes doing 500+ mph air resistance is more of a thing. Then again the jet stream could be handy for them if blowing the right way.
• ngcc_hk 7y ago
  Suppose those who can get breeding advantage somehow and should be in your list of reasons.