Migratory Wonders of the Wild
Happier of happy though I be, like them
I cannot take possession of the sky,
Mount with a thoughtless impulse and wheel there
One of a mighty multitude, whose way
And motion is a harmony and dance
Magnificent…
~William Wordsworth
Nothing describes the wonder of flight better than these words from Wordsworth. Winter is still here (thankfully!) and our feathered friends continue to fascinate us with their aerial antics, we can literally feel these joyful words as we look up to the skies. I often dwell upon the almost mystical abilities of these birds to stay airborne for hours, and cannot help but feel a sense of wonder at the most amazing antic- that of migration. Humans have learnt to go beyond boundaries in the true sense maybe since the past decade or two, but these birds, they have pioneered a tradition of cross-geography travels and wistful journeys since times immemorial! Truly, there must be something magical about this ability of theirs, and I thought of delving into the what, why and how of the migration magic.
Why do birds migrate?
The reason for migration is back to the basics- to maximise resource availability i.e. birds move from a region of low resources to a region of high resources. Birds have a very simple definition of resources unlike us humans, it boils down to the abundance of food and nesting locations. Geographic conditions such as cold weather also determine the nature of migration- it can be short-distance or long-distance. What truly mesmerizes is the phenomenon of long-distance migrations, where these tiny beings gather all their brawn and brains to fly thousands of kilometres, every year. And to make things even more magical, much of this migratory flight is a result of the genetic makeup of these birds, passed on over generations. So, if we humans take pride in visiting our ancestral home-towns during vacation, it would be noteworthy to know that birds do the same without the adequate tools like compasses, Google Maps or scheduled flights, as we humans have. Birds independently find their perfect summer homes in tropical retreats, enjoying the abundance of insect life and sunny cheer!
How do birds migrate?
What triggers migration is exactly not known. Migratory behaviour is much an ingrained behaviour, may be triggered by changes in the day length, temperatures, dwindling of food supplies etc. In fact, the onset of an “urge to migrate” has been given a scientific name by German scientists- Zugunruhe or “migratory restlessness”. It is breath-taking how these tiny beings follow the same aerial paths as their forefathers, even without having seen those paths before! And to think they achieve this milestone feat without the due resources that man has come to depend on. But hey, nature has its own way of equipping and empowering a resourceful life for these beings. The sun and stars act as the compass, the earth’s magnetic field acts as a direction determiner, so much so that landmarks seen during the day are believed to egg them on year after year! Some studies also indicate that smell is an important contributor to the migration accuracy. What’s more, they are intelligent enough to sometimes modify their routes depending on resource availability- eBird* data has revealed that many small birds take different routes in spring and fall. Truly, our underestimated little birdies are navigational experts of their own accord, unlike what any fighter jet place or sci-fi rocket could ever achieve!
Of course, such a phenomenal act cannot be undertaken without effort and grit. Migration is no walk (or flight) in the park, it demands nerves of steel. It is a test of birds’ physical and mental capabilities. They face the risks of starvation, weather changes and mortality due to human intervention during already arduous tasks. Despite this, long-distance migratory birds somehow know that this is their only way of life- to have a summer home and then a winter home. Without this, their kith and kin would be susceptible to resource-depletion, death and maybe even, extinction. And so, they uphold this tradition, year after year.
Birds can Definitely Boast of Bravado!
Birds have it in them to boast about their theatrics. Here are some interesting species with even more interesting migratory stories!
- Bar Headed Goose is one of the highest-flying bird in the world. They migrate to India every winter season. They fly right over the lofty Himalayas and reports have indicated them flying over Makalu – the fifth highest mountain on earth at 8,481 m (27,825 ft) above sea level to enjoy some warm weather in the tropical states from Assam to Tamil Nadu.
- A wonder of long-distance migration is the Sooty Shearwater, which migrates a distance of about 64,000 miles from New Zealand to the North Pacific Ocean every summer.
- Another enviable specimen of long-distance migration is the Arctic Tern, which is believed to fly a million kilometres – nearly three times the distance from the Earth to the moon during its lifetime of about 25 years.
Migration and humans: A delicate link
Much of migration happens in set patterns i.e. set paths and set timelines. This predictability factor has made it easy for humans to anticipate and intervene in this natural wonder. One eye-opening example is the case of the Amur Falcon, a small raptor which shot to fame due to its rampant hunting-down during its migratory stop in Nagaland. Every year, this small bird leaves its breeding grounds in Siberia and China to move to Africa, taking a pitstop in the luscious hills of North East India. After all, it is not easy to complete an estimated journey of 22,000 kilometres without a refuelling and energizing break. But this pitstop turned out to be a fatal stop for the resilient birds, for their resilience and bravery could not stand the onslaught of human beings. The tribal folk of Nagaland developed a habit of anticipating these bird’s stop-over and laying down nets to ensnare the unsuspecting birds and kill them. Falcon meat is considered a delicacy in Nagaland, and this was literally an easy annual catch. It was only in 2012 that an estimate was put to the number of Amur Falcon deaths- 120,000 to 140,000 birds done-to-death in a jiffy. Human intervention at the better end i.e. from the Nagaland Forest department, conservationists and the government realised this annual pattern and through extensive education and communication encouraged the masses to protect and not annihilate the beautiful species. This is a classic example of how migration can make birds susceptible to threats, and how only the right measures can keep this awe-inspiring phenomenon kicking and alive. We must understand that these aerial beauties are at their vulnerable best during their migratory phase, and if we humans do not aid them in their life-endeavours, this wonder comes to an end. What a pity that would be- not just a death of denizens, but a death of bravery and beauty.
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Aparna Mondal
Beautiful piece of writing !would love to read many more like this. Very informative indeed.