Nesting Ecology of a Small Montane Population of the Nigerian/Cameroon Chimpanzee (Pan troglodytes ellioti) in Nigeria

Abstract

Understanding nest site choice by chimpanzees has implications for ecology, anthropology, and in the collection of census data, yet it remains controversial. Here we provide the first information on environmental factors affecting nest site choice in a montane population of the rare and relatively understudied Nigerian/Cameroon chimpanzee (Pan troglodytes ellioti) in Ngel Nyaki Forest Reserve, Nigeria. The forest is small, isolated, and visited by researchers, community members, and hunters. We also tested the hypothesis that people (researchers) walking along forest trails collecting data on a regular basis since 2005 will have changed nesting behaviour in the vicinity of the trails. Along the trails searched for nests, the chimpanzees used a subset of 35 (28.5%) of all available tree species. The top 5 nest tree species represented 16% of all non-nest tree species. The nest trees were on steeper than average slopes and the trees themselves were shorter and had a smaller DBH (diameter at breast height) than trees without nests. We found no evidence to suggest a change in nesting behaviour along trails compared with off trails; however, the average nest height today is considerably higher than it was in 2004, which may indicate a change in behaviour across the whole forest.

Nesting behavior of the savanna chimpanzee (Pan troglodytes verus) in the non-protected area of Bantankiline (Kedougou, Senegal)

“…Ainsi, le dénombrement des nids est couramment utilisé par les chercheurs pour estimer la taille des populations, en particulier le chimpanzé, et pour identifier les sites et espèces végétales qu'ils utilisent pour la nidification. Il permet aussi d'avoir des informations sur l'alimentation, le repos nocturne, les couloirs de migration empruntés, etc… (Pruetz et al, 2002 ;Kühl et al, 2008 ;Hernandez-Aguilar, 2009 ;Ukpong et al, 2013 ;Hakizimana et al, 2015 ;Dutton et al, 2016 ;McGrew, 2007).…”

Nest-Building Behaviour by Chimpanzees (Pan troglodytes verus) in the Non-Protected Area of Diaguiri (Kedougou, Senegal): Implications for Conservation

“…However, it is generally difficult to observe wild great apes in their natural habitat. Thus, nest count surveys are commonly used by researchers (1) to estimate great ape population sizes and (2) to determine habitats used for nesting and related aspects of nesting behaviour, especially for unhabituated apes [Pruetz et al, 2002;Kühl et al, 2008;Hernandez-Aguilar, 2009;Ukpong et al, 2013;Hakizimana et al, 2015;Dutton et al, 2016;McGrew, 2017].…”

“…In Lagoas de Cufada Natural Park, in Guinea, chimpanzees made 52.7% of their nests in Dialium guineense [Carvalho et al, 2015]. In Bagnomba (Senegal), 63% of the chimpanzee nests were in Diospyros mespiliformis and Pterocarpus erinaceus [Badji et al, 2018] [Dutton et al, 2016]. In Bwindi National Park (Uganda), chimpanzees make nests in 38 of 163 tree species, and 72.1% of nests (n = 2,463) were constructed in just 4 species: Cassipourea sp., Chrysopyllum gorungosanum, Drypetes gerrardii and Teclea nobilis [Stanford and O'Malley, 2008].…”

The montane trees of the Cameroon Highlands, West-Central Africa, with Deinbollia onanae sp. nov. (Sapindaceae), a new primate-dispersed, Endangered species

“…About 80% of the seedlings survived, and they grew 4.5–5.5 cm over the 3 months ( Matthesius, Chapman & Kelly, 2011 ). Deinbollia “pinnata” is one of 28 identified tree species used by chimpanzees as nesting trees at Ngel Nyaki, but is not among the preferred top five ( Dutton, Moltchanova & Chapman, 2016 ).…”