At least ten birds endemic to the Western Ghats – a biodiversity hotspot – are more under threat than previously thought, an international study has found.
The International Union for Conservation of Nature (IUCN) draws up a Red List that assigns a threat status – from critically endangered to least concern – to various species which results in countries taking efforts towards their conservation.
Now a new study has said IUCN “greatly underestimates threat levels of endemic birds in the Western Ghats” by over estimating the geographic range of the habitat of birds resulting in underestimating threat. Assessing 18 endemic bird species of the Western Ghats the study has revealed that threat status for at least 10 birds needs to be up-listed, and range maps of 17 birds has been over estimated to a large extent.
IUCN releases it classification of threat levels for birds based upon range maps prepared by BirdLife International (BLI), a global partnership of conservation organisations. Species found in larger areas are deemed less threatened than species found in smaller areas. The study found that more than half of the species were not found in over 60% of the areas mapped by BLI.
For instance, the Nilgiri pipit should be classified as ‘endangered’ from the IUCN status as ‘vulnerable’. Even its geographical range has been over estimated – it has a range of less than 1392 sqkms as compared to BLI’s range of 11,000 sqkms.
Similarly, the Wynaadlaughingthrush should be up-listed from its present ‘least concern’ category to ‘near threatened’ with its range over estimated by 85% - BLI’s range is 1, 54, 095 sqkms as against 24,557 sqkms as estimated in the study.
“There are many areas where birds don’t occur today. Areas where there are townships and developmental projects have been considered as part of the BLI range,” Vijay Ramesh, lead author, a spatial and computational ecologist at the US-based Cary Institute of Ecosystem Studies told HT in an email interview. Columbia University, Cornell University, and Duke University were also part of the study.
Researchers said that unlike BLI that does not consider environmental information that drive the distribution of the species, their study has considered temperature, precipitation, elevation, land cover and environmental features. “Upon comparison, we realized that most of these ranges are inaccurate and the true ranges for these birds are much smaller than previously thought,” said Ramesh. “Such a study is important because we need to know where these birds are actually found today so that we can conserve these natural habitats for the future. In a landscape like the Western Ghats, which has undergone rapid transformation, it is important that we conserve crucial habitats for the future.”
The four-member team prepared maps for the 18 endemic birds based on data from eBird, the online birding checklist started by the Cornell Lab of Ornithology that based on sightings by millions of citizen scientists and compared them with maps used by IUCN.
Co-author Trisha Gopalakrishna, who was at Duke University at the time of the study said this new approach to range modelling could have broad-reaching implications for multiple stakeholders. “With accurate ranges, scientists will be able to better study the effects of human disturbance and climate change on bird habitat,” said Gopalakrishna. “Conservation planners can have greater confidence in the areas that they are managing. In the policy arena, our findings could inform future delineation of parks, high-value conservation areas, and community forests.”
