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Friday, February 12, 2010

IS IT THE SWAN SONG FOR SIBERIAN CRANES

Swan song : means a final gesture or performance, given before dying.


Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. These however are usually irregular or in only one direction and are termed variously as nomadism, invasions, dispersal or irruptions. Migration is marked by its annual seasonality.
The first natural historian to write about migration as an observable fact was Aristotle. Aristotle was an astute observer and is known to have recorded the times of departure of some species from Greece, and listing Pelicans, Turtle Doves, Swallows, Quail, Swans and Geese correctly as migrants he accurately observed that all migrating birds fatten themselves up before migrating. Scientific investigation of bird migration began in 1802 when birds were tagged with metal leg bands. The numbering of the rings is controlled by a national body in most countries and the rings have a contact address on them. Hundreds of thousands of birds are banded around the world each year, by amateurs and professionals. In India, it was only in the 1960s that effective bird ringing projects became possible.

Now coming back to ‘swan song’ – the term is derived from the legend that, swans remain mute throughout their life time but sing beautifully and mournfully just before they die. Though swan song is figuratively used to refer celebrated performers making their farewell tours or final performances, this isn't true in reality as even the inaccurately named Mute Swans, have a variety of vocal sounds and they don't sing before they die. But to ornithologists, the spotting of Siberian cranes in India is amiss and perhaps the cranes had had a swan song.

The Siberian Crane, Grus leucogeranus, also known as the Siberian White Crane or the Snow Crane, is a bird of the family Gruidae, the cranes. This species breeds in arctic Russia in Yakutia and western Siberia. It is a long distance migrant. The eastern population winters on the Yangtze River and Lake Poyang in China, the central population at Keoladeo National Park, India and the western population in Fereydoon Kenar in Iran. It breeds and winters in wetlands, where it feeds on the shoots, roots and tubers of aquatic plants.

This is a large white crane, typically 4.9-8.6 kg (10.8-19 lbs), 140 cm (55 in), and 210–230 cm (83–91 in) across the wings. Large males can exceed 152 cm (60 inches) and weigh over 10 kg (22 lbs). Adults are all white, except for a dark red mask extending from the bill to behind the eye and black primary wing feathers. It has a yellow iris and reddish legs. The male is slightly larger than the female. Juveniles have a feathered mask and buff or cinnamon plumage. The voice is flute-like and musical. On an examination of specimens, researchers found aquatic plants in their stomach, however, they are noted to pick up beetles and birds eggs.
At the time of bombing at Afghan areas by US fighter jets in pursuance of rooting out the taliban regime in 2001 – the cranes could still find their way to India but alas the last Siberian Crane in India was not to be seen thereafter.

When it comes to migration, the Arctic Tern has the longest-distance migration of any bird, and sees more daylight than any other, moving from its Arctic breeding grounds to the Antarctic non-breeding areas. One Arctic Tern, ringed (banded) as a chick on the Farne Islands off the British east coast, reached Melbourne, Australia in just three months from fledging, a sea journey of over 22,000 km (14,000 miles). A few seabirds, such as Wilson's Petrel and Great Shearwater, breed in the southern hemisphere and migrate north in the southern winter. Seabirds have the additional advantage of being able to feed during migration over open waters.
In this context, the majestic Siberian cranes skipping India this winter (actually for the tenth consecutive year) makes a sad reading. Experts apprehend that the Siberian Cranes are unlikely to ever come to the Bharatpur region of Rajasthan again as they have apparently changed their centuries-old migratory route from Siberia to India. The bird lovers and ornithologists trying for a glimpse of the bird have been in for disappointment. All along their route to India was though Afghanistan. The dwindling size of the most endangered species have also added to this – as per authoritative international estimates, there are barely 3200 siberian cranes left in the world. The central population which used to come to India during winter is now considered extinct – the eastern population has around 3000 and it is also under threat owing to changes in their wintering areas in China, attributable to construction of huge Three Gorges Dam.

Reports state that at its peak, in 1965, Bharatpur hosted over 200 Siberian Cranes. Less than 30 years later, in 1993, only five were sighted there. Then, after a gap of three years, four were spotted in 1996. That was reduced to barely a pair of these birds by the late 1990s, following by the last pair seen in 2001.

The predominant cause could well the loss of natural habitat and there are reports of hunting of these huge birds in Afghan & Pakistan.  The famed winged travelers of long distance in trying to escape the cold winter of Siberia flying over Russia, Kazakhstan, Uzbekistan, Afghanistan, Pakistan and then to northwestern India with a brief halt at Abi-I-Istada Lake in Afghanistan reaching Bharatpur in around eight week could bleakly turn to be a thing of the past.

Unfortunately this could add one more to the long list of extinct birds and animals brought more about by man’s greed to encroach everywhere and spoil the environ without any concern.

S. Sampathkumar.

2 comments:

  1. Hello,
    This is a really good read for me. Must admit that you are one of the best bloggers I ever saw. Thanks for posting this useful article.

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  2. Hei really itneresting... great read.. you are a fine blogger. alisha from tehran with love

    ReplyDelete