Natures wonders: Migrating geese conserve energy (Introduction)

by David Turell , Sunday, January 18, 2015, 19:29 (3595 days ago) @ David Turell

Flying low when they can, but flying over the Himalayas when they have to:-http://www.livescience.com/49470-roller-coaster-goose-flight.html?cmpid=558956-" The tracking data also showed that the birds flapped their wings more frequently at higher altitudes, where the air is less dense. But more important, a small increase in the wingbeat frequency was strongly correlated with a large increase in the heart rate. For example, a 5 percent increase in the wingbeat rate produced a 19 percent change in the birds' heart rate, Bishop said.-"This all suggests that as the birds increased their altitude, they had to flap their wings harder to generate the same amount of lift, and this used up a lot of energy. Thus, it makes more sense for the birds to swoop down to lower altitudes when the ground dips down, Bishop explained."