(After gathering the data for the study from 2013 to 2015, Dr. Karanth co-founded a coffee company, Wild Kaapi. Charlotte Chang, an ecologist at Princeton University and another author on the paper who is not associated with the company, said Dr. Karanth’s enterprise became active after the data gathering and interpretation was completed.)
The researchers counted 204 species of birds on the coffee plantations, including at-risk species, such as the Alexandrine parakeet, the grey-headed bulbul and the Nilgiri wood-pigeon.
Anand Mandyam Osuri, a postdoctoral research scientist at Columbia University’s Earth Institute, who was not involved in the work, said it provided new insights into how changes to the coffee crop affect bird diversity.
“Even this seemingly subtle land transition can decrease the diversity of bird species that are important for conservation,” Dr. Osuri said in an email, but “the arabica-robusta transition might have relatively small impacts on bird communities in comparison to other land transitions in the Western Ghats.”
The findings show that farming is not incompatible with wildlife protection, said Jai Ranganathan, a conservation biologist and senior fellow at the National Center for Ecological Analysis and Synthesis, at the University of California, Santa Barbara, who was not involved in the research.
“Is it possible for humans and nature to thrive together? The Western Ghats says the answer can be yes,” he said, noting that the rain forests of the Western Ghats are a global hot spot for biodiversity. “There are many other examples of win-win situations in Western Ghats, which have naturally developed.”
While ethical farming has taken off in the United States and other Western countries, Dr. Karanth said she is trying to promote the idea in India, where people are not yet used to spending a premium to ensure that their consumer goods are produced in an environmentally sound way.
That premium, she said, could provide the economic incentive for farmers to keep growing coffee, rather than switching to a commodity like rubber, which requires them to cut down trees, and therefore hurts wildlife. “As long as people keep trees on their land, birds will be fine,” she said.
An earlier version of this article misstated the number of bird species counted by researchers. It was 204, not 106.