BENGALURU: Recent scientific findings show how shade-grown coffee supports as many as 204 bird species, including 13 endemic birds of the Western Ghats. The other plants that also support these species are areca and rubber.
In one of the largest scientific assessments of tropical birds in the world, a two-year study in Karnataka has found that coffee plantations were supporting a higher diversity of birds.
Covering an area of 30,000 sq km in seven Western Ghats districts, researchers evaluated that coffee plantations were richer in bird species compared to rubber and areca plantations. Further, it showed how along with protected areas (PAs), privately-owned plantations were also playing a pivotal role in conserving avian diversity.
Author of the paper Dr Krithi K Karanth, Associate Conservation Scientist, Wildlife Conservation Society, New York, said, “The effort involved intensive research in 187 plantations. The study was restricted to dry season but excluding migrant bird species. The sampled agroforests ranged between seven and 800 acres. This was one of the largest field-based assessments of bird species outside PAs in the Asian tropics.”
The study found that bird densities were highest in coffee for low canopy, mid-canopy and high canopy guilds (a group of plants) and this may be due to more native shade trees as in PAs. Thirteen endemic species found in these agroforests belonged to the high canopy variety.
Leading ornithologist and co-author of the paper Shashank Dalvi added, “Large-bodied frugivores (fruit eating species) such as pigeons and hornbills were found in much higher densities in coffee. These birds play an important role in seed dispersal and maintenance of forest trees in the region.”
Role of plantation crops
Karnataka contributes 69 per cent of coffee production, 53 per cent of areca and 3 per cent of rubber production to the country. With PAs covering less than 9 per cent area of the 1.6 lakh sq km of the Western Ghats, it becomes critical to assess the role of agroforests in biodiversity conservation.
Habitat support
Coffee is grown in mid-high elevations and are shade grown under a mixture of native and exotic tree canopy. Areca is grown in mid-low elevations and inter-cropped with coconut, banana and cocoa. Rubber on the other hand is found at low elevations and mono-cropped with no native or introduced species.
Conserving wildlife
Plantations and agroforests host a diversity of insects, amphibians, reptiles, mammals, birds and bats. In the Western Ghats, small and isolated PAs are embedded in a matrix of multiple land uses, most of which include agroforests. These are being increasingly recognised for their supplementary role in conserving wildlife.