Bar-headed geese make one of the most dramatic migrations on the planet. The species epic trek is more impressive than the march of the penguins; it puts the monarch’s winter jaunt to Mexico to shame.
Every year as snow and ice descend upon the Mongolian plains, bar-headed geese leave their breeding grounds and fly over the tallest mountain range in the world to southeastern Tibet and India. And new research suggests they have an unique way of scaling the Himalayas.
Most biologists assumed the geese borrowed the strategy of a jet plane, ascending to incredibly high altitudes and cruising until their descent on the other side. But after scientists implanted a group of geese with tracking devices, researchers realized the birds never actually fly far from the ground.
“The logical assumption is, they would spend a lot of time flying very high,” study co-author Charles Bishop, a zoologist at Bangor University in Whales, told LiveScience. “When we went to measure it, we found they seldom seemed to be that high above the ground.”
The tracking devices showed that the birds ascended and descended with the contours of the mountains, pitching and yawing, rising and falling, diving and rolling — like a roller-coaster.
The reasons for this are two-fold, Bishop and his colleagues found.
Because the thinner air at high altitudes creates less drag, some scientists previously believed flying way up there might be less stressful. But the tracking devices — which measured the animals’ heart rates in addition to altitude — proved the birds had to work twice as hard and flap their wings twice as fast to create lift. The workout would have been too much to sustain for a long period of time.
And descending on the other side of each mountain crest not only saves precious energy, it also improves the birds chances of catching an updraft.
“By staying close to the ground they can maximize those opportunities,” Bishop told NPR. “It’s smart, isn’t it? Nature seems to always select animals to do things economically, and do it the best way.”
Started in year 2010, ‘Climate Himalaya’ initiative has been working on Mountains and Climate linked issues in the Himalayan region of South Asia. In the last five years this knowledge sharing portal has become one of the important references for the governments, research institutions, civil society groups and international agencies, those have work and interest in the Himalayas. The Climate Himalaya team innovates on knowledge sharing, capacity building and climatic adaptation aspects in its focus countries like Bhutan, India, Nepal and Pakistan. Climate Himalaya’s thematic areas of work are mountain ecosystem, water, forest and livelihood. Read>>