Natural History Wanderings

The Environment New Network has a story on how Bar-headed Geese can fly at 23, 000 with so little oxygen. At this high altitude is air is only made up of 7% oxygen, compared with 21% at sea level. Researchers found that the geese had a remarkable tolerance of low oxygen conditions both at rest and while they were exercising for 15 minutes at top speed. The key seems to be that bar-headed geese are able to oxygen to their heart muscles at a much faster rate than other species. The more they can supply, the faster they can beat their hearts and keep the supply of oxygen to the rest of the body going. ead more at:  Wildlife and Habitat Conservation News: At more than 23,000 feet, why don’t bar-headed geese get hypoxic?.