B Sivakumar, TNN | Feb 10, 2014, 05.51AM ISTFifteen species of birds seen in India have been declared critically endangered by the International Union for Conversation of Nature (IUCN) for 2013. The endangered birds, including the Great Indian Bustard, Siberian Crane, White backed Vulture and Red-headed Vulture, are on the decline, said a report of IUCN updated till December 2013.

The major reasons for the decline in the population of these birds include loss, modification, fragmentation and degradation of habitat, environmental contaminants, poaching and land use changes, particularly conversion of large areas for crop cultivation. Also, changes in cropping pattern due to various reasons, including implementation of irrigation schemes, increased pesticide usage, livestock-grazing, high levels of disturbance and developmental activities like mining and hydel projects resulted in marginal fall in their population, said the report.

Threats posed by infrastructure development, such as collisions with vehicles, power-lines and wind turbines pose danger to the birds.

The other birds in the revised list are Baer's Pochard, Forest Owlet, Bengal Florican, Spoon-billed Sandpiper, Sociable Lapwing, Jerdon's Courser, Whitebellied Heron, Slender-billed Vulture, Indian Vulture, Himalayan Quail and Pink-headed Duck.

Studies by Bombay Natural History Society (BNHS) and similar organisations on what contributes most to the decline of several bird species revealed that just like wetlands, most other habitats such as grasslands and forests also faced severe threat due to development pressures. Destruction of deciduous forests in central India has led to the decline in Forest Owlet numbers.

Destruction of forests in the Western Ghats and the Himalayas continues to endanger many other species, an official of BNHS said.

Replying to a query in the Rajya Sabha , Union environment minister Veerappa Moily said India was a signatory to several major international conventions relating to conservation and management of wildlife, including endangered species of birds. "Financial and technical assistance is provided to state/Union territory governments for protection and management of protected areas as well as other forests under centrally-sponsored schemes," he said.

The government has banned the veterinary use of diclofenac drug that has caused rapid population decline of Gypsy vulture across the Indian subcontinent . Conservation breeding programmes to protect these vulture species have been initiated at Pinjore (Haryana), Buxa (West Bengal) and Rani, Guwahati (Assam) by the Bombay Natural History Society, he said.

The Siberian Crane, one of the longest migratory crane species, visits the Keoladeo National Park in Rajasthan during winter. It used to travel 3,500 miles every winter to the park but has been missing in the last few years. Similarly, other migratory birds from other parts of the world, which come to India during winter have declined, said BNHS official.