If you thought rising pollution was harming only humans, give a thought to our winged friends.
The deteriorating air and water quality in the National Capital Region ( NCR) has forced many species to disappear altogether, while the rest are facing extinction.
Ornithologists claim only 20 per cent of birds that earlier existed are now present. The rest have either migrated towards open, cleaner areas or have died.
"Birds are very sensitive. They can thrive only in clean air and require highly clean water. Any contamination leads to their death in 90 per cent of cases.
Like humans, they are susceptible to diseases and are infected with similar ailments," Parichit Gautam, ornithologist and director of the fresh water and wetlands programme, WWF India, said.
"At almost all bird sanctuaries, the number of birds is fast depleting. Even at the Okhla Bird Sanctuary along Delhi, the number of birds coming from Central Asia has reduced," he added.
"Of the 100 cases that come to my notice, 80 per cent suffer from ailments caused by air pollution.
Since the respiratory tracts of birds are sensitive, they catch diseases very quickly," said Dr Deepak Chaudhary, ornithologist and veterinary surgeon of western UP's largest bird hospital - Jain Bird Hospital, Kavi Nagar.
"All respiratory diseases are life- threatening as they affect the entire breathing process.
The survival rate of birds suffer- ing from respiratory diseases is just 5 per cent," he said.
Birds are most prone to Ranikhet viral disease, in which either their neck gets twisted or moves only in one direction.
Birds are also highly vulnerable to foul pox, which has the same symptoms as chicken pox in humans. Birds develop rashes on the beak, legs and the whole body.
Birds are also diagnosed with bronchitis, bronchiolitis and tuberculosis. " We have to keep such birds in separate enclosures to keep other birds safe," Chaudhary said.
Polluted air also causes loss of appetite, pneumonia, eyeinfection, chronicle coryza disease( cold, cough) and laryngitis in birds.
"We give antibiotics for bacterial infections. There are also some medicines available for viral diseases but there's no remedy for chronic diseases," he said.
Contamination in drinking water causes diarrhoea.
Some of the migratory birds most vulnerable to pollution include the Siberian cranes, greater flamingo, ruff, blackwinged stilt, common greenshank, northern pintail, yellow & white wagtail, northern shoveler, gadwall, black- tailed godwit, spotted redshank, starling and long- billed pipi. Birds such as Asian koel, black- crowned night heron, Eurasian golden oriole, comb duck, bluecheeked and blue- tailed beeeater also tend to catch diseases fast, specialists said.
Among the resident birds, common hoopoe, purple sunbird, little cormorant, Indian roller, white- throated kingfisher, spot billed duck, rose- ringed parakeet, red- collared dove, laughing dove and greater coucal are highly prone to respiratory ailments.
Respiratory tract infections and chronic ailments in animals are also widely reported from Noida, Ghaziabad and surrounding areas.
"The breathing mechanism of animals ceases to function as a result of intensive pollution and chokes their respiratory organs completely, eventually leading to death. The death rate in animals, particularly dogs is also rising," Chaudhary said.