Assessment of the relationship between rainfall patterns and human-elephant conflict in Nochchiyagama and Vanathavilluwa, Sri Lanka

Abstract

Wilpattu National Park (WNP), the largest and oldest national park in Sri Lanka, spans across eight Divisional Secretariats (DS), where Human-Elephant Conflict (HEC) remains a significant concern. This research investigates the HEC in areas surrounding WNP and examines its correlation with rainfall patterns. A questionnaire survey was conducted in Nochchiyagama, the most densely populated of the eight DS divisions, to capture farmers’ perspectives on HEC. The HEC data were collected from the Department of Wildlife Conservation from 2015 to 2022 across the eight DS divisions and the highrisk and low-risk areas were identified. Additionally, rainfall data of Nochchiyagama and Vanathavilluwa DS divisions from 2015 to 2022 were examined to explore any potential relationship between rainfall and HEC incidents. Findings indicated that Cheddikulam and Karuwalagaswewa are high-risk divisions for HEC, while Rajanganaya is the lowest risk division. According to the survey, 71.3% of respondents believe that elephants invade villages searching for food where 45.5% of total responses indicate that coconut is the most attractive crop to elephants. Mangoes were the second most preferred crop (36.4%), followed by Kurakkan and paddy (26.4% each), and pumpkin, corn, and sugarcane (22.3%, 19.8%, and 16.5%, respectively). All respondents were familiar with elephant repellent methods, with "ali Vedi" being the most prominent. Additionally, 47.2% of respondents suggested establishing an electric fence to minimize conflict, while constructing ditches and using shotguns were recommended by 30.4% and 22.4% of respondents, respectively. Rainfall patterns in Nochchiyagama and Vanathavilluwa showed minor variations, with January-March and JuneSeptember being relatively dry periods, and March-June and September-December being rainy months. Despite 56% of survey respondents indicating that elephant incursions predominantly occur during the dry season, statistical analysis (Spearman test, p = 0.260, p = 0.347) found no significant correlation between HEC and rainfall in either division over the study period. In summary, while the study highlights areas and crops most affected by HEC and identifies community-preferred mitigation strategies, no significant correlation was found between rainfall patterns and HEC incidents. Although there is no direct relationship between rainfall and HEC, the HEC is influenced by the other proximate factors related with food availability which are in turn affected by the rainfall. Therefore, there might be an indirect relationship between rainfall and HEC in Nochchiyagama and Vanathavilluwa. Further research is recommended to confirm this idea and investigate seasonal variations in elephant movements and behaviors in other areas surrounding WNP to develop more effective mitigation strategies.