Some mammals make use of cashew nut plantations in the Sindhudurg district of Maharashtra, reveal camera trap images from a new study that for the first time examines the presence of wildlife from nearby forests in cashew plantations in the Western Ghats.
“Our findings are important because they give us hope that if cashew farms near forests are sustainably managed, then both people and wildlife can coexist,” said Anushka Rege, lead author of the study and doctoral student at Nanyang Technological University, Singapore. “This could pave the way for developing sustainability initiatives for cashew crop, like what has been done for coffee and cocoa.”
There is much more work needed to make this a reality, Rege points out. Increasing our understanding of how various taxa respond to cashew land use and prioritising the needs of local landowners is important, emphasises Rege. One of the world’s eight ‘hottest hotspots’ of biodiversity, the Western Ghats is a 1,600 km-long chain of mountains running parallel to India’s western coast and stretches across the states of Kerala, Tamil Nadu, Karnataka, Goa, Maharashtra and Gujarat. The study took place in the northern Western Ghats in the state of Maharashtra.
As more and more forested land is converted for agriculture and plantations, the long-term persistence of animals depends on how they use modified landscapes along with the ability of people to coexist with wildlife. While protected areas are important, they are limited in spatial extent and a “lot of wildlife persists in human-dominated landscapes, which are far larger and widespread,” Rege said.
“This study reiterates the importance of production landscapes interspersed with remnant forests for biodiversity conservation in the Western Ghats,” said Anand Osuri, a scientist at the Nature Conservation Foundation who was not involved in the study. Cashew is an “important plantation crop that tends to get ignored in discussions on conservation in the Western Ghats and elsewhere in the tropics,” he notes.
Native to Brazil, cashews are cultivated in 33 countries across the tropics with India and Vietnam being top producers of the nuts. In India, the states of Maharashtra, Andhra Pradesh and Odisha have the largest land areas under cashew cultivation.
Cashew nut trees (Anacardium occidantale) are perennial and grow to adult heights of about 5 to 14 metres in 7 to 10 years. Cashew plantations often have a layer of understory bushy growth, which is periodically removed to facilitate harvesting.
The case of wild pigs
The study took place in a mixed forest-cashew landscape in the Tillari region of Dodamarg tehsil in the Sindhudurg district of Maharashtra from January to April 2016. The landscape is located on a large mammal corridor between three protected areas. Sindhudurg district was chosen because it has the highest area under cashew cultivation in the state of Maharashtra. Ranging in elevation from 50 to 1,030 metres above sea level, vegetation in the Tillari region comprises moist deciduous forests with semi-evergreen forests along riparian patches.
With the help of local field assistant Narayan Desai, Rege deployed trail cameras over an area of 25 sq km, which was divided into 100 grid cells of 0.25 sq km each. In each grid cell, six trail cameras were installed for a period of 24 hours.
The cameras captured 11 species in forests and nine of these were recorded in cashew plantations. The nine species included sambar, Indian crested porcupine, wild pig (wild boar), gaur, Indian hare, Indian gray mongoose, small Indian civet, leopard and common palm civet.
Apart from porcupines, wild pigs and sambar, all other species had very low capture rates, which suggest that only a few generalist species can flourish in human-modified landscapes. Capture rates for the Indian crested porcupine, Indian gray mongoose, Indian hare and gaur were higher in cashew plantations than in forests.
With the guidance of coauthors Girish Arjun Punjabi, Devcharan Jathanna and Ajith Kumar, Rege analysed the results and modelled the probability of habitat use of the three most photographed species—Indian crested porcupine, sambar and wild pig—with respect to the type of habitat, distance to the forest edge and other characteristics. Wild pigs were more likely to use cashew nut plantations near human settlements and away from forest edges. However, the use of farms by wild pigs is not a new phenomenon said Rege, adding that they have been recorded in human-dominated areas across the world.
Wild animals, especially pigs, could be using cashew nut plantations for multiple reasons: loss of nearby forests, access to cashew nuts for food or to avoid predation. Cashew nuts are strewn on the soil during harvest season (February to May) so they are easy to consume, Rege says, noting that wild animals have been known to bite into the hard and caustic cashew nut shells and fruits as reported by farmers in the study. “Cashews may have weedy undergrowth and bushes, which might be food for some ungulates,” adds Rege.
Osuri agrees with the authors calling for more research on other kinds of animals in order to develop a more comprehensive understanding of the conservation potential of cashew plantation landscapes. “It would also be important to understand existing and emerging threats to biodiversity in cashew plantations, such as changes in cultivation practices that might impact habitat quality or land-use conversion from cashew to less biodiversity-friendly habitats,” he adds.
Working with locals to ensure coexistence and wildlife-friendly farms
While researchers are reporting these findings, locals are living with these realities for ages and are aware of them, says Rege, who emphasises engaging with locals and tapping into their knowledge. “The combined powers of these two streams of knowledge would be best to come up with plans on how to foster coexistence,” she proposed.
“We need to come up with a way to ensure the farmers receive a fair minimum price for their organic produce, and in turn, they can grow organic cashew with some wildlife-friendly farm characteristics such as keeping the native trees in their farms intact, not hunting, and so on.” In addition, the agriculture and forest departments can work with locals to think of ways to minimise losses whilst ensuring wildlife is protected, Rege adds.
One of Rege’s next projects involved interviewing cashew farmers about their land management practices and interactions with wildlife. In a study that is yet to be published, her team found that sambar, gaur, porcupine and wild pig contributed the most to crop loss. “We also see that some farmers were aware that deforestation and rapid cashew expansion were bad in the longer run, but there is a conflict of this thought with the need to expand farms, produce higher yields and earn more.”
Rege is now mapping cashew plantations using remote sensing tools and working on using bioacoustics tools to understand biodiversity levels across privately-owned forests, Reserved Forests and cashew plantations.