Most Indian birds declining, finds new report using citizen science data

For millennia, birds have been inherently intertwined in Indian culture, playing prominent roles in mythology, religion, art, and other aspects of human life. A new comprehensive report on the state of India’s birds, released this week at the 13th Conference of Parties to the Convention on Migratory Species in Gandhinagar, reveals that most Indian birds have been declining, particularly raptors such as vultures and eagles. On the other hand, populations of species like peafowls are increasing while sparrows are stable.

The overall health of Indian birds has been unknown because research tends to focus on a handful of bird species, typically those that are larger, more threatened and charismatic. But now, scientists from ten research and conservation organisations within the country, spanning both governmental and non-governmental institutions, collaborated to assess the distribution range, abundance, and conservation status for 867 bird species that regularly occur in India.

“We really did not know the status of our common species,” Ashwin Viswanathan, one of the study authors from the National Conservation Foundation told Mongabay-India. This report sheds light on “habitats that may require attention now,” he said, warning that “so many common species that we thought were doing okay require attention from researchers, scientists and conservationists and policymakers.”

For the pioneering report, the researchers harnessed data contributed by more than 15,500 birdwatchers across the country, comprising over 10 million bird observations, uploaded to the online platform eBird India. Recognising the power of such data, the researchers stressed the need for greater collaborations with birdwatchers and naturalists.

“The public is doing great now by showing so much interest in birds and by sharing observations on a public platform and so that is quite amazing,” said Viswanathan, emphasising that if the public continues to share their observations, “then that is really as good as it gets.”

Data-backed classification of Indian birds

Using the information on range size along with IUCN Red List Categories, the researchers classified 101 species of ‘High Conversation Concern’ in India. Of these, 48 species are endemic to India (found nowhere else in the world) and among them, 12 have ranges restricted to the Western Ghats. Worryingly, these Western Ghats endemics have suffered an almost 75 percent drop since 2000—even common species such as Crimson-backed Sunbird and Yellow-browed Bulbul.

Sutirtha Dutta from the Wildlife Institute of India, who was involved in the study, said we do not know the underlying causes and can only speculate at this stage. “The strong long-term decline of the whole range of Western Ghats endemics may suggest that the drivers of their decline possibly operate at a regional scale,” he said, adding that further studies are needed.

“The State of Indian Birds is possibly the most exhaustive document yet produced on Indian birds that is focused on conservation,” said Ghazala Shahabuddin, a scientist at the Dehradun-based not-for-profit organisation Centre for Ecology, Development and Research, who was not connected to the study. She added the report “makes the leap from speculation and informed guesses to rigorous data-based inferences.”

Among the 101 species of High Conservation Concern, 34 species have not been listed as globally threatened in the IUCN Red List. “Some of those species depend greatly on India in terms of their global range and for those species, their status should be changed because their status in India is their global status in a sense but for many species that have much larger ranges across the world and only a small part of their range is in India, the Indian assessment can feed into the global assessment,” explained Viswanathan.

Fall in raptors

While 48 percent of species have remained stable or increasing in the long term (over more than 25 years), 79 percent have been decreasing over the past five years. Although worrying, these results are not surprising, stated Viswanathan, as they are in line with global assessments. A study from North America published last year also reported a staggering decline in bird populations.

Groups that have seen more than 50 percent decline over the long-term include scavenging and open country raptors, migratory shorebirds, gulls and terns, forest and grassland specialists, long and short distance migrants, Western Ghats endemics, and carnivores.

Observing a sharp drop in raptors that depend on open habitats like grassland and scrub, Viswanathan pointed out that such habitats have been generally neglected in terms of conservation efforts and policies. “We need to immediately focus on research and conservation efforts on understanding what is happening with the raptors to understand why they are declining. That would be a focus on grassland habitats, focus on prey, understanding whether pesticide use has an effect.”

The Great Indian Bustard is a grassland species and is the largest among four bustard species in India, all of which have declined in population. Over the past five decades, its populations and distribution range has plunged by around 90 percent. Collision with power lines has proven deadly and institutions such as Bombay Natural History Society, BirdLife International, Wildlife Institute of India and other organisations are working to develop ways to make infrastructure conservation-friendly.

Vultures have suffered catastrophic declines over the past few decades, owing to the use of the anti-inflammatory drug diclofenac in livestock. Consistent with the results of a monitoring study by the Bombay Natural History Society and Royal Society for the Protection of Birds, the report finds that White-rumped Vulture suffered the steepest decline since 2000, followed by Indian Vulture.

Shahabuddin said that these findings have “strong implications for policy and conservation action.” The Indian government, she suggests, should “take urgent note of these findings and prioritise conservation of forests, wetlands, coasts, grasslands and other ecosystems so that further biodiversity losses can be stalled immediately.”

She further noted: “One lacuna in this report is the lack of attention to agricultural habitats as an important repository of bird diversity. For the species that appear not to be affected as much by the onslaught of habitat change and decline, it is possible that the bird-friendly agricultural habitats have been acting as a refuge.”

Peafowls flourishing, house sparrows stable overall 

But the findings are not all that grim. The team found that 126 species are stable or increasing in the long-term. Peafowl, India’s national bird distributed across hills and plains, has increased in population both in the long-term and over the past five years.

Although the reasons are unclear due to lack of information, a recent study from the wet state of Kerala noted the increasing expansion of peafowls in the state where they were formerly absent, explained Viswanathan. They could be increasing because of a drying trend due to climate change in parts of the Western Ghats, he speculated, adding that there may be various reasons and this is just one possibility. “Another possibility could be better protection because peafowls are Schedule I of the Wildlife Protection Act.”

There has been widespread concern that House Sparrows are disappearing in India, especially in urban areas, and it was suspected that a drop in both insect populations and nest sites might be contributors. Even radiation emitted from mobile phone towers was thought to be a cause, but there is no evidence to support this theory, the report stated. Indeed, the study noted that their abundance in large metro cities—Bengaluru, Chennai, Delhi, Hyderabad, Kolkata and Mumbai—has declined gradually. But when considering their entire range over India, they have remained stable over the past 25 years.

These surprising results “underline the importance of large numbers of observations undertaken over large spatial scales, over the long term, and in a range of habitats,” stressed Shahabuddin, noting that previous observations were limited to urban environments.

The authors called for research efforts to be stepped up immediately to identify causes of the decline of the 101 species of High Conservation Concern and accordingly implement appropriate conservation actions to halt and reverse the downward trend.

 

Banner image: Among all Indian vulture species, white-rumped vultures have suffered the sharpest decline. Photo by Davidvraju/Wikimedia Commons.