Journal Article

Habitat differentiation among three Nigeria–Cameroon chimpanzee (Pan troglodytes ellioti) populations

Mounga, Albert, Doudja, Roger, Ambahe, Ruffin, Morgan, Bethan J., Fotso, Roger C., Kentatchime, Fabrice, Venditti, Dana M., Mitchell, Matthew W., Ketchen, Marcel E., Fosso, Bernard, Abwe, Ekwoge E., Teguia, Eric, Gonder, Mary Katherine, Tchiengue, Barthelemy

2019

Overview

Ecological niche models (ENMs) are often used to predict species distribution patterns from datasets that describe abiotic and biotic factors at coarse spatial scales. Ground‐truthing ENMs provide important information about how these factors relate to species‐specific requirements at a scale that is biologically relevant for the species. Chimpanzees are territorial and have a predominantly frugivorous diet. The spatial and temporal variation in fruit availability for different chimpanzee populations is thus crucial, but rarely depicted in ENMs. The genetic and geographic distinction within Nigeria–Cameroon chimpanzee (Pan troglodytes ellioti) populations represents a unique opportunity to understand fine scale species‐relevant ecological variation in relation to ENMs. In Cameroon, P. t. ellioti is composed of two genetically distinct populations that occupy different niches: rainforests in western Cameroon and forest–woodland–savanna mosaic (ecotone) in central Cameroon. We investigated habitat variation at three representative sites using chimpanzee‐relevant environmental variables, including fruit availability, to assess how these variables distinguish these niches from one another. Contrary to the assumption of most ENM studies that intact forest is essential for the survival of chimpanzees, we hypothesized that the ecotone and human‐modified habitats in Cameroon have sufficient resources to sustain large chimpanzee populations. Rainfall, and the diversity, density, and size of trees were higher at the rainforest. The ecotone had a higher density of terrestrial herbs and lianas. Fruit availability was higher at Ganga (ecotone) than at Bekob and Njuma. Seasonal variation in fruit availability was highest at Ganga, and periods of fruit scarcity were longer than at the rainforest sites. Introduced and secondary forest species linked with anthropogenic modification were common at Bekob, which reduced seasonality in fruit availability. Our findings highlight the value of incorporating fine scale species‐relevant ecological data to create more realistic models, which have implications for local conservation planning efforts. We examined specific abiotic factors and biotic conditions predicted by ecological niche models (ENMs) to differentiate two distinct genetically distinct populations of the Nigeria–Cameroon chimpanzee (Pan troglodytes ellioti) at a fine geographic scale using chimpanzee‐relevant variables, such as fruit availability. The results revealed that while ENMs are useful for understanding habitat suitability at a broad scale, more attention needs to be given to incorporating species‐specific requirements at a spatial and temporal scale that is biologically relevant for the species.

• Publisher: John Wiley & Sons, Inc,John Wiley and Sons Inc,Wiley
• Subject: Anthropogenic factors / Availability / Biotic factors / Chimpanzees / Density / Distribution patterns / ecological niche models / Ecological niches / Ecology / ecotone / Forests / Fruits / ground‐truthing / Habitats / human‐modified landscape / Introduced species / Lianas / Niches / Original Research / Pan troglodytes / Pan troglodytes ellioti / Population genetics / Populations / Rainfall / rainforest / Rainforests / Seasonal variations / Temporal variations / Woodlands