They weren't nearly that tall then though. E.g.: > “The bar-heads have done that migration for millions of years before the Himalayas were as tall as they are

They weren't nearly that tall then though. E.g.: > “The bar-heads have done that migration for millions of years before the Himalayas were as tall as they are now, and the birds have been pushed as the mountains have moved up to go higher and higher,” says coauthor Julia York, now a graduate student at the University of Texas at Austin, in an interview with the Times. York, who played foster parent to seven geese, adds, “They’re amazing athletes.” https://www.the-scientist.com/news-opinion/bar-headed-geese-slow-their-metabolism-to-soar-over-everest-66386 https://www.the-scientist.com/news-opinion/bar-headed-geese-...