Dwindling bird diversity in city a cause for concern

Dwindling bird diversity in city a cause for concern

The Hindu

Several changes have contributed to the decrease in birdlife


Bangalore: "Can anyone measure the aesthetic value, the songs and colours, that birds add to the world around us?" asked Zafar Futehally, a senior ornithologist. How often is it that one gets to hear the chirps and twittering of birds? Seems like ages ago.

Ornithologists have expressed concern over the dwindling bird diversity in the city. Most of them blame it on the changes in the city's landscape and the increase in all kinds of pollution.

Speaking to The Hindu, Dr. Futehally said the city had not been planned from an ecological point of view. Several exotic trees from other countries, which had no natural base, such as nectar, seeds and fruits that were essential for birds to survive, had been planted in many parts of the city.

"If the city's planners had planted local trees, such as tamarind, neem and mango, we would not be facing such a situation. However, there has been an increase in the number of scavenger birds such as Pariah Kites and House Crow. We still have not learned to dispose of our rubbish in a proper manner," he said.

In 1996, a group of bird watchers came out with an annotated checklist of all birds that were spotted within a 40-km radius of the Vidhana Soudha. The group had documented over 220 species of birds, Dr. Futehally said.

Reasons for reduction

Bird diversity increases as one moves from one gradient to the other, such as core urban, urban, rural-urban and rural, experts say.

"The life of a lake is in the shore line. This is where insects and small amphibians such as crabs breed. But with the cementing of shores of lakes in the city, we are depriving the birds of their food," said M.B. Krishna, an ornithologist.

Shore birds, such as sand plowers and sandpipers, were the most affected.

He also said that though the city grew, the green spaces had decreased tremendously. Valleys that were repositories of water had been flattened for development of layouts.

A.M. Annaiah, Deputy Conservator of Forests (Urban), said the unchecked growth of aquatic weeds, increase in the use of pesticides, and release of industrial effluents had drastically increased pollution in tanks, which were responsible for the decrease in the oxygen levels in the water bodies.

Change in vegetation, in terms of reduction in shrubbery and smaller plants, decrease in the number of houses with gardens, cementing of courtyards, increase in sound pollution and construction activity in and around lakes have contributed to the decrease in birdlife.

Though several ornithologists affirm the reduction in birdlife in the city, A.K. Verma, Principal Chief Conservator of Forests (Wildlife), maintained that there had been no serious reduction in the number of birds over the past two-three years.

"However, there definitely has been a reduction when compared to the situation during the 1970s," he said.

Samuel Jacob, an amateur bird watcher, said, "If we cannot save a simple species such as House sparrow, it is indicative of our failure. Having birds around impacts the way we perceive our environment. We cannot afford to live in our cocoon. We have to see other life around us."

Birds that were more sensitive to the changes in the eco system were the most affected. "If we create habitats that are conducive for the growth of scavenger birds, we will be able to spot only them in the skies, which is the case in some parts of the city already," he said.