A little cock sparrow sat on a tree, and he chirrupped and he chirrupped so merrily"
This
nursery rhyme was part of one's lexicon during the formative years. Its
main protagonist, the sparrow, was equally a delight to watch and hear
early mornings. But today, as one marks the "World Sparrow Day" on March
20, one wonders where these little passerines have disappeared.
Some
say radiation from the host of modern-day gadgets and their
transmission infrastructure have taken a toll on them. Other say they
are vanishing due to lack of habitat in the city and dearth of food --
mainly insects on which the little ones feed.
According to the
World Wide Fund for Nature (WWF), house sparrows had evolved with humans
instead of forests. Both had peacefully co-existed till not so long ago
-- in houses and gardens. "But in the last two decades, their
population is on the decline in almost every city," the fund said.
"As
green spaces in our cities give way to more concrete constructions, the
house sparrows loses its foraging ground, affecting the availability of
seeds and worms," WWF said, prompting Nature Forever Society of India
and the Eco-Sys Action Foundation of France to get them back home.
The
fund also said with an increase in human population in cities, there
also come other species -- such as domestic cat, which is a top predator
of the house sparrow. Also on the rise are preying birds like kites and
owls, which now pose a serious threat to the fragile sparrow habitat.
One
research into dwindling population of sparrows prompted a 12-year-old
girl in Mumbai, Mehek Mehta, entitled "The Sparrow Project: Decline of
Sparrow Population in Urban Areas" won her the silver medal at the Homi
Bhabha Bal Vaidyanic Competition held recently.
"I came across a
newspaper article stating that radiation from mobile towers affected
sparrows and other birds. I found this very shocking: If tiny birds like
sparrows are affected by mobile towers, then what silent effects would
it have on humans?" she queried
"This prompted me to select this
topic for my research project," Mehta said. Her conclusion: The
electro-magnetic waves emitted from mobile towers don't have any
alarming effect on the habitat of sparrows and other birds.
She
concluded her project by saying the diminishing sparrow population in
Mumbai and other areas was a factor of environmental and ecological
changes which are yet to be perceived by humans. But predominantly, it
is the loss of food and nesting places that are the culprits.
This young girl was guided by experts in radiology Prof. Mahendra Karkare and her father Dr Mehool Mehta.
Since
there was also a belief that mobile tower radiations interfere with the
auditory mechanism of sparrows and disturb their habitat, Mehek
specifically researched on the frequencies of such emissions and found
the range was between 900 MHz and 1800 MHz.
She conducted her
research by visits to more than 21 places, with and without mobile
towers. She particularly found that the range of radiation far exceeded
the upper limit of the hearing range of sparrows, which is 250 Hz to 18
Khz.
Mehta also found that house sparrows are usually found close
to human habitation and cultivation and that the frequencies in mobile
towers and handsets fall in the non-ionizing category and a sound beyond
this range is ineffective in causing changes in the behavior of
sparrows.
(Aparajita Gupta can be reached at [email protected])
