@misc{FotangBroeringRoosetal., author = {Fotang, Chefor and Br{\"o}ring, Udo and Roos, Christian and Enoguanbhor, Evidence Chinedu and Dutton, Paul and T{\´e}donzong, Luc R. D. and Willie, Jacob and Yuh, Yisa Ginath and Birkhofer, Klaus}, title = {Environmental and anthropogenic effects on the nesting patterns of Nigeria-Cameroon chimpanzees in North-West Cameroon}, series = {American Journal of Primatology}, volume = {83}, journal = {American Journal of Primatology}, number = {9}, issn = {1098-2345}, doi = {10.1002/ajp.23312}, pages = {12}, abstract = {Environmental conditions and human activity influence the selection of nest sites by chimpanzees and may have serious conservation implications. We examined the characteristics of nesting trees preferred by chimpanzees, investigated the effect of vegetation composition and topography on nest site locations and seasonality on nesting heights of chimpanzees, and verified the effect of predator occurrence and human activity on the nesting behavior of the Nigeria-Cameroon chimpanzee (Pan troglodytes ellioti) in Kom-Wum Forest Reserve (KWFR) and surrounding unprotected forest in Cameroon. We recorded 923 nests, 502 signs of human activity, and 646 nesting trees along line transects and recces (reconnaissance) for two seasons. We found that chimpanzees constructed more arboreal nests on tall primary trees with high lowest branch height and large diameter at breast height. Moreover, they oriented their nests within trees in the slope direction when the nesting trees were located on slopes. Additionally, the occurrence of chimpanzee nests was positively related to increasing elevation and slope and decreased with distance to primary forest. In contrast, the number of nests increased with distance to secondary forest, open land, and villages, and nesting height was not influenced by seasons. While we recorded no signs of large nocturnal chimpanzee predators at nesting trees, we found signs of hunting activity at nesting locations. Nesting high in trees is likely a way of avoiding hunting, while nest orientation within trees in slope direction shortens escape routes from human hunters. Our findings suggest that chimpanzees select safe trees (tall trees with high lowest branch height) located in nesting areas (primary forest, high elevation, and steep slopes) that are not easily accessible by humans. Therefore, conservation efforts should focus on protecting primary forests at high elevation and steep slopes and reducing human impact.}, language = {en} } @misc{FotangBroeringRoosetal., author = {Fotang, Chefor and Br{\"o}ring, Udo and Roos, Christian and Enoguanbhor, Evidence Chinedu and E. Abwe, Ekwoge and Dutton, Paul and Schierack, Peter and Angwafo, Tsi Evaristus and Birkhofer, Klaus}, title = {Human activity and forest fragmentation threaten populations of the Nigeria-Cameroon Chimpanzee (Pan troglodytes ellioti) in Western Cameroon}, series = {International Journal of Primatology}, volume = {42}, journal = {International Journal of Primatology}, number = {1}, issn = {1573-8604}, doi = {10.1007/s10764-020-00191-2}, pages = {105 -- 129}, abstract = {Increased human activities such as commodity-led deforestation, extension of agriculture, urbanization, and wildfires are major drivers of forest loss worldwide. In Cameroon, these activities cause a loss of suitable primate habitat and could ultimately threaten the survival of chimpanzees (Pan troglodytes). We derived independent estimates of the population size of the Endangered Nigeria-Cameroon chimpanzee (Pan troglodytes ellioti) in Kom-Wum Forest Reserve, Cameroon, and surrounding unprotected forest areas through 1) direct observations, 2) camera trapping, 3) distance sampling, 4) marked nest counts, and 5) standing crop nest counts. In addition, we georeferenced signs of chimpanzee and human activity along line transects. We used a generalized linear mixed model to predict the occurrence of chimpanzees in response to edge length (measured as the perimeter of core forest patches), core area of forest patches (measured as area of forest patches beyond an edge width of 100 m), habitat perforation (measured as the perimeter of nonforested landscape within core forest patches), patch size(measured as area of forest patches), and forest cover. Chimpanzee density estimates ranged from 0.1 (direct observation) to 0.9 (distance sampling) individuals km-2 depending on estimation method with a mean nest group size of 7 ± 5.4 (SD). The mean encounter rate for signs of chimpanzee activity was significantly higher in mature forests (2.3 signs km-1) than in secondary forests (0.3 signs km-1) and above 1000 m elevation (4.0 signs km-1) than below 1000 m (1.0 signs km-1). The mean encounter rate for signs of human activity was significantly higher in secondary (8.0 signs km-1) than in mature forests (0.9 signs km-1). Secondary forests, habitat perforation, and edge length had a significant negative effect on the occurrence of chimpanzee signs. Overall, human activity and forest degradation affected the number of observed chimpanzee signs negatively. Regular antipoaching patrols and reforestation programs in degraded areas could potentially reduce threats to populations of endangered species and may increase suitable habitat area.}, language = {en} }