Indian bird species decline a source of concern

Released on August 25, the State of India’s Birds 2023 (SoIB) sets off several warning bells. As the report’s website states, the study assessed 942 species of Indian birds after processing 30,000,000 observations by birdwatchers that then form the basis of the analyses. The report alarmingly finds that 39% of species show clear declines over the past decades, while 178 species classified as of High Conservation Priority, and require immediate attention. Birds in India are known to be affected by factors including (but not limited to) land-use change, urbanisation, ecosystem degradation, monocultures, disease, infrastructure development, pet trade, hunting, pollution, and climate change. Wild bird populations and assemblages can be impacted by these threats in complex ways and at different spatial scales.

The State of India’s Birds report was created to assess the conservation status of the majority of species that regularly occur in the country, the website points out. Worldwide, common and widespread species are declining; but in India, lack of information has meant that conservation attention has been focussed on only a few species (usually large, charismatic and threatened).

The report, in its second iteration, fills this gap by using over 30 million observations uploaded to the eBird platform by more than 30,000 birdwatchers to evaluate the distribution range size of 942 Indian birds, and their trends in abundance in both the long term (over 25+ years) and currently (since 2015). Using these three measures, plus information from the IUCN Red List of global threat status, this report places Indian species into Low, Moderate and High categories of Conservation Priority for India. A large number of species that are thought to be common and widespread find themselves as of High Conservation Priority.

After a gap of three years, this second edition provides an update based on a much larger information base – with a mammoth 30 million field observations from over 30,000 birdwatchers spanning across the country, thus enabling more species to be assessed. In this edition, new sections have been introduced to emphasize the importance of systematic monitoring of birds as well as the various threats to birds in India. SoIB 2023 extends and updates the assessments presented in SoIB 2020 by adding four years of data, amounting to 20 million additional data points. This has enabled a larger number of species to be evaluated (867 in 2020 versus 942 in this report) and has been accompanied by several refinements in analytical methodology.

The overall outcome of these assessments largely reflects the global trend: some generalist species are doing well, while the many bird species show various degrees of decline. The International Union for Conservation of Nature (IUCN) Red List shows that 49% of bird species worldwide are declining in population, compared with only 6% increasing. In India, generalist species like feral Rock Pigeon, Ashy Prinia, Asian Koel and Indian Peafowl are doing very well. Other common species like the Baya Weaver and Pied Bushchat are relatively stable.

But the larger picture is grim: 60% of species show long-term declines (out of 348 species that could be assessed for Long-term Trend), and 40% of species are declining currently (out of 359 species assessed for Current Annual Trend). The declines are not spread uniformly across different types of species; examining differences across groups of species that share common characteristics reveals informative patterns.

The report finds that habitat specialists – particularly birds of grasslands and other open habitats, wetlands, and woodlands – are declining rapidly. In terms of diet, carnivores, insectivores, and granivores are declining more rapidly than omnivores or fruit- and nectar-eaters. Separately, migratory species appear to be under greater threat than non-migrants. And species endemic to the Western Ghats–Sri Lanka region are faring worse than others.

Certain groups of birds are faring particularly poorly, including open habitat species like bustards and coursers, riverine sandbar-nesting birds like skimmers and some terns, coastal shorebirds, open-country raptors, and a number of ducks. The finding that a large number of common species are in trouble is a cause for concern. Equally worrying is that a considerable number of species lack the data to be assessed.

Insufficiency of data meant that of the 942 species covered in this report, Long-term Trend could not be calculated for 44% and Current Annual Trend could not be estimated for 31% of the species. The report summarises implications that flow from the findings and makes broad recommendations for bird conservation in the country.