Occurrence and ecological niche modelling of Irvingia gabonensis at cross river state, Nigeria


  • Akwaji Patrick Ishoro Department of Plant and Ecological Studies, Faculty of Biological Sciences, University of Calabar, P.M.B. 1115, Calabar, Cross River State, Nigeria
  • Ugbogu Omokafe Alaba Department of Forest Conservation and Protection, Forestry Research Institute of Nigeria (FRIN), Jericho Hills, Ibadan, Oyo State, Nigeria
  • Chukwuma Emmanuel Chukwudi Department of Forest Conservation and Protection, Forestry Research Institute of Nigeria (FRIN), Jericho Hills, Ibadan, Oyo State, Nigeria
  • Tanimu Yahuza Department of Botany, Ahmadu Bello University, Zaria, Kaduna State, Nigeria
  • Soyewo Temitope Luke Department of Forest Conservation and Protection, Forestry Research Institute of Nigeria (FRIN), Jericho Hills, Ibadan, Oyo State, Nigeria




Biodiversity, climate change, conservation


The African bush mango, Irvingia gabonensis Baill, 1884 (Aubry-lecomte ex o’rorke) is a diverse species whose edible seeds are commonly used as a delicacy in soups and as a main source of income throughout Cross River State, Nigeria. Given its enormous economic value for the rural population, we investigated current and future occurrence, geographic distribution, and suitable and unsuitable habitats in the face of unsustainable use and changing climate scenarios. Our study assessed and marked the occurrence of I. gabonensis using Global Positioning System (GPS) software in 36 forested areas encompassing northern, central and southern geographical zones of Cross River State, Nigeria. Maximum Entropy (MaxEnt) was applied to forecast the ecological niche of I. gabonensis currently and in the future under the AfriClim (RCP 8.5) 2070 scenario. The performance of the MaxEnt model was gauged by the ‘area under the receiver operating characteristic curve’ (ROC) and the complementary ‘area under the curve’ (AUC), ‘variable contribution rate, ‘jackknife tests’ and true skill statistics (TSS). MaxEnt results set quadruple BioClim variables (‘BIO 6 - minimum temperature of coldest month’, ‘BIO 12 - annual precipitation’, ‘BIO 13 - precipitation of coldest month’, and ‘BIO 14 - precipitation of driest month’ as most important decisive variables playing a role in the geographic distribution of the species. Currently, 94.79% of Cross River State is suitable habitat for I. gabonensis, with future projections showing a significant 79.59% reduction in suitable habitat at the ‘minimum training presence’ threshold. Only a few secure areas (20.41%); Afi Mountain Wildlife Sanctuary (central zone), Cross River National Park, Okwangwo Division (central zone) and Oban Division (southern zone) will continue to exist as suitable habitats for the species. The results achieved call attention to the need to protect, cultivate breed and initiate the species in the preferred areas.


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How to Cite

Ishoro, A. P. ., Omokafe Alaba, U. ., Chukwudi, C. E. ., Yahuza, T. ., & Temitope Luke, S. . (2023). Occurrence and ecological niche modelling of Irvingia gabonensis at cross river state, Nigeria . Journal of Wildlife and Biodiversity, 7(supplementary issue), 96–127. https://doi.org/10.5281/zenodo.10023259