Abstract
Elephants influence the structure and composition of African woodlands and, sometimes, damage cultivated trees in farms of local communities. Here, we evaluate the impact of elephant debarking on cultivated cashew trees (Anacardium occidentale) as the friction between farmers and elephant conservation is increasing. We quantified the effects of elephant debarking on tree survival, crown defoliation, and nut production by visiting elephant-damaged farms with cashew trees (n = 47 farms) along Sasawara National Forest (Tanzania). We also compared defoliation and nut production with nearby control trees (undamaged) in a paired designed. Our results reveal that elephants debarked a significant proportion of trees (36% of farms had some cashew trees damaged by elephants, with a mean of 17.3% damaged trees per farm), with a preference for medium-large tree sizes (> 20 cm of diameter at breast height). Tree mortality due to elephants was 4 trees (4.2% of the affected trees), which represents around 0.1% of the total number of trees in the affected farms. In the year of damage, elephant debarking caused no effect on defoliation whereas nut production was reduced only in trees with very high intensity of damage (> 60% of trunk circumference affected). However, a year after the damage, both defoliation and nut production were negatively affected but this effect was strongly dependent on the intensity of damage and tree diameter. These results may help reduce the social discomfort of cashew farmers and contribute to enhance human-elephant coexistence. However, further studies should analyze the future vulnerability of damaged trees to fires, pathogens or pests.
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The data that support the findings of this study is available as Supplementary information in Table S4.
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Acknowledgements
We would like to thank TAWIRI (Tanzanian Wildlife Research Institute) and the Tanzanian Commission for Science and Technology (COSTECH) for granting permission for the implementation of the study. We also thank Saidi Halifa Amigo (Village Game Scout of Chingoli WMA) for his assistance in the field and Universidad Politécnica de Madrid-Funded Research, Development and Innovation Program for making it possible.
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This work was supported by Universidad Politécnica de Madrid-Funded Research, Development and Innovation Program (specifically the Funding for pre-doctoral contracts for the completion of doctoral degrees at UPM schools, faculties, and R&D centers).
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María Montero Botey: investigation, conceptualization, formal analysis, and writing original draft. Ramón Perea: methodology, writing-review and editing, and supervision.
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Montero-Botey, M., Perea, R. An increasing human-elephant conflict? Impact of African elephant on cultivated cashew trees. Eur J Wildl Res 69, 5 (2023). https://doi.org/10.1007/s10344-022-01629-z
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DOI: https://doi.org/10.1007/s10344-022-01629-z