The relationship between the abundance of the Nigeria-Cameroon chimpanzee (Pan troglodytes ellioti) and its habitat: a conservation concern in Mbam-Djerem National Park, Cameroon

Serge Alexis Kamgang,Mary Katherine Gonder,Brice Sinsin,Kadiri Serge Bobo,Désiré Edgar Ambassa Ongono,Paul Johnson,Ruffin Dupleix Delarue Ambahe,Fiona Maisels,Jorgelina Marino

doi:10.1186/s12898-018-0199-3

Abstract

BackgroundUnderstanding the relationship between great apes and their habitat is essential for the development of successful conservation strategies. The chimpanzee Pan troglodytes ellioti is endemic to Nigeria and Cameroon, and occupies an ecologically diverse range of habitats from forests to forest-savannah mosaic in Mbam-Djerem National Park (MDNP) in Cameroon. The habitat variation in chimpanzees is poorly understood in MDNP which provides an excellent opportunity to assess ecological factors that shape the abundance and distribution patterns of P. t. ellioti over a small geographic scale.ResultsWe counted 249 nests along 132 km of transects in total. Of these, 119 nests along 68 km occurred in dense forest and 130 nests along 64 km in forest-savannah mosaic. Chimpanzee density was 0.88 [95% CI (0.55–1.41)] individuals/km2 in the dense forest and 0.59 [95% CI (0.19–1.76)] in the forest-savannah mosaic. Nest abundance varied with vegetation type and was higher in areas with dense canopy cover, steeper slopes and relatively higher altitudes.ConclusionsOur estimates of chimpanzee densities were lower than reported in other studied populations in the range of the Nigeria-Cameroon chimpanzee. However, we found that habitat features, slope and altitude likely play a role in shaping patterns of chimpanzee nesting ecology. Further studies need to be focused on nest decay rates and phenology of useful plants in order to model chimpanzee abundance and distribution in Mbam-Djerem National Park.

Highlights

Understanding the relationship between great apes and their habitat is essential for the development of successful conservation strategies
The larger error associated with the chimpanzee density estimate might be explained by the use of a non-site specific nest decay rate as the later depends on the environmental variables of the study site [12] and the intrinsic limitations attributed to the survey method
This study provides the first systematic assessment of the effect of habitat variability on the density of chimpanzees in the Mbam-Djerem National Park (MDNP), revealing that gallery forest and colonising forest are preferred by chimpanzees in the core area, while highlighting characteristics of habitat that are positively associated with nest abundance and high conservation importance

Summary

Introduction

Understanding the relationship between great apes and their habitat is essential for the development of successful conservation strategies. The chimpanzee Pan troglodytes ellioti is endemic to Nigeria and Cameroon, and occupies an ecologically diverse range of habitats from forests to forest-savannah mosaic in Mbam-Djerem National Park (MDNP) in Cameroon. The habitat variation in chimpanzees is poorly understood in MDNP which provides an excellent opportunity to assess ecological factors that shape the abundance and distribution patterns of P. t. The Mbam-Djerem National Park (MDNP) in Cameroon offers an excellent opportunity to assess ecological factors shaping the abundance and distribution of the Nigeria-Cameroon chimpanzee (Pan troglodytes ellioti) over a small geographic extent in the core zone of the protected area, which includes both dense forest, colonizing forest and savannah ecosystems. As the forest is currently expanding [6] and replacing savannah in MDNP [7], understanding how chimpanzees use different habitats can inform conservation efforts by providing key monitoring parameters on behalf of this species

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