Nilgiri pipit seeks better status as habitat shrinks

  • As the threat of Nilgiri pipit going locally extinct looms large, bird researchers are urging the IUCN to uplist the status of the bird from ‘vulnerable’ to ‘endangered’.
  • A new study highlights the urgent need to actively restore montane grasslands and encourage conservation efforts to save the unique bird and its shrinking habitat. 
  • The authors note that underestimating the threat levels of range-restricted endemic species may further imperil the existence of threatened species.

If there’s one avian resident of the Western Ghats that has captured the imagination of both birders and researchers alike, it’s the Nilgiri pipit. Not for its flamboyant plumage, mind you. Indeed, if aesthetic allure is what you seek in a bird, then the Nilgiri pipit would largely disappoint. However, this seemingly unremarkable bird stands out for its distinctive ecological niche. Endemic to montane grasslands of the Western Ghats, it is a specialist in its habitat preferences. Typically found at high altitudes of 1,600 metres or above, the Nilgiri pipit (Anthus nilghiriensis) is highly range-restricted which makes it vulnerable to multiple threats from climate change to habitat fragmentation and degradation.

Grasslands with restricted distributions are found in montane regions across the tropics, where they often form a mosaic with tropical montane forests. These tropical montane grasslands host unique and endemic species which makes its conservation all the more crucial.

Habitat loss as an immediate threat

As grasslands continue to diminish across India, species like the Nilgiri pipit face the looming spectre of habitat loss. Researchers are increasingly concerned that it may be one of the endemic species of the montane shola grasslands of the Western Ghats teetering on the brink of extinction due to this drastic environmental degradation. Some ecologists like V.V. Robin, associate professor at IISER-Tirupati, confirms the bird faces high extinction rate from habitat loss. Nilgiri-based naturalist and restoration practitioner Vasanth Godwin Bosco observes that he is seeing fewer numbers of the bird which makes local extinction a possibility but only anecdotally. “In the absence of data and evidence, we cannot claim that,” he remarks.

But much to the chagrin of bird researchers, despite this imminent risk, Nilgiri pipit is listed as “vulnerable” on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. In their latest study, scientists Robin, Abhimanyu Lele and team try to make a case for uplisting its status to “endangered” by highlighting that the montane grassland fragmentation, degradation and shrinkage has left the Nilgiri pipit with less than 500 km2, even using the most conservative threshold.

Nilgiri pipit is unique for its choice of habitat, the montane grasslands. Photo by Abhimanyu Lele.

Robin and Lele in an email correspondence with Mongabay-India say that the study sends out a larger conservation message that the Nilgiri pipit is under more threat than has previously been recognised, and that both the species and its habitat are in urgent need of protection. They highlight that the threat has mostly come from the spread of woody invasives such as Acacia into native montane grasslands and there is an urgent need to address it. “Luckily, we have evidence that sustained efforts can effectively restore montane grassland habitat,” they write.

Bosco concurs. During his decade-long grassland restoration effort in the Nilgiris, Bosco has noticed the bird visiting restored patches at an altitude of about 2,000 metres. “They don’t reside in those patches, but visit frequently,” he points out. This has secured his belief in the potential of grassland restoration.

Global warming challenges bird survival

The threat of global warming too looms large on the high elevation montane species. Robin and team address this in their  2014 paper saying that the species is occurring more frequently in grasslands above 1,900 metres, spread over just two mountain-tops, making this species one of the most range-restricted birds in India.

Bosco sees global warming as a larger threat now as the grassland degradation has reached a saturation point. He has also observed invasive species like Tithonia diversifolia or Mexican sunflower responding quickly to warming, moving up and colonising the areas previously occupied by native species. “Native species in higher altitudes are so scarce now,” he notes.

Habitat degradation and climate change are threatening the survival of the highly range-restricted  Nilgiri pipit. Photo by Abhimanyu Lele.

Dependence on eBird data for range estimation of high altitude birds is another tricky area that the paper addresses. While the authors agree on eBird data being a valuable resource for assessing the distribution of a species, they warn against the pitfalls. They urge that the data be approached with caution as it has been found to use larger and sometimes flawed estimates. “We identified several reasons why ebird data may be problematic for the Nilgiri pipit, including spatial bias in sampling and difficulty in separating the Nilgiri pipit from other pipits that may appear similar to an observer unfamiliar with the species,” they inform. Avian ecologist Vijay Ramesh who uses eBird data in his studies believes that by applying the right filters and accounting for biases, the data can be useful to bird researchers. He highlights the example of the recent State of India’s Birds report that relied extensively on eBird data. However, in the case of elusive, range-restricted species like Nilgiri pipit, the authors recommend a range estimate based on expert surveys as more robust.

Previous attempts by researchers to uplist the bird have been overlooked due to lack of quantitative backing. The paper argues that “accurately assessing the range and distribution of range-restricted endemic species is critical in creating valid threat assessments; underestimating threat levels may further imperil the existence of threatened species.” As a key conservation action for the bird and its habitat, the authors recommend restoration of grasslands via sustained removal efforts, as well as careful and long-term management of the restored patches.

Read more:  [Book Review] A walk down the Nilgiri hills 


Banner image: A Nilgiri pipit in the montane grasslands. One of the endemic species to the high altitudes of the Nilgiris, the bird faces an imminent threat of local extinction. Photo by Abhimanyu Lele.

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