Hey guys you are not quite correct...birds can fly at the level of commercial airlines that fly around 34,000 feet. Here is something I found on the bird pages:
"The highest-flying bird ever recorded was a Ruppell's griffon, a vulture with a wingspan of about 10 feet; on November 29, 1975, a Ruppell's griffon was sucked into a jet engine 37,900 feet above the Ivory Coast--more than a mile and a half higher than the summit of Mount Everest. The plane was damaged, though it landed safely.
In 1924 a yellow-billed chough, a crowlike bird that's among the highest-nesting species, followed a climbing expedition's food scraps to 26,500 feet on Everest. The avian altitude record in North America is held by a mallard, which collided with an airplane on July 9, 1963, at 21,000 feet above Elko, Nevada.
Several other bird species regularly brave extreme altitudes. Among them are whooper swans, which were once observed by a pilot at 27,000 feet over the Atlantic Ocean between Iceland and the European continent, and bar-tailed godwits, which have been spotted at almost 20,000 feet. And then there's the occasional hardy individual that makes a high-altitude cameo.
cheers
Andy