• Chimpanzee population structure in Cameroon and Nigeria is associated with habitat variation that may be lost under climate change

      Sesink Clee, Paul R.; Abwe, Ekwoge E.; Ambahe, Ruffin D.; Anthony, Nicola M.; Fotso, Roger; Locatelli, Sabrina; Maisels, Fiona; Mitchell, Matthew W.; Morgan, Bethan J.; Pokempner, Amy A.; et al. (2015)
      Background: The Nigeria-Cameroon chimpanzee (Pan troglodytes ellioti) is found in the Gulf of Guinea biodiversity hotspot located in western equatorial Africa. This subspecies is threatened by habitat fragmentation due to logging and agricultural development, hunting for the bushmeat trade, and possibly climate change. Although P. t. ellioti appears to be geographically separated from the neighboring central chimpanzee (P. t. troglodytes) by the Sanaga River, recent population genetics studies of chimpanzees from across this region suggest that additional factors may also be important in their separation. The main aims of this study were: 1) to model the distribution of suitable habitat for P. t. ellioti across Cameroon and Nigeria, and P. t. troglodytes in southern Cameroon, 2) to determine which environmental factors best predict their optimal habitats, and 3) to compare modeled niches and test for their levels of divergence from one another. A final aim of this study was to examine the ways that climate change might impact suitable chimpanzee habitat across the region under various scenarios. Results: Ecological niche models (ENMs) were created using the software package Maxent for the three populations of chimpanzees that have been inferred to exist in Cameroon and eastern Nigeria: (i) P. t. troglodytes in southern Cameroon, (ii) P. t. ellioti in northwestern Cameroon, and (iii) P. t. ellioti in central Cameroon. ENMs for each population were compared using the niche comparison test in ENMtools, which revealed complete niche divergence with very little geographic overlap of suitable habitat between populations. Conclusions: These findings suggest that a positive relationship may exist between environmental variation and the partitioning of genetic variation found in chimpanzees across this region. ENMs for each population were also projected under three different climate change scenarios for years 2020, 2050, and 2080. Suitable habitat of P. t. ellioti in northwest Cameroon / eastern Nigeria is expected to remain largely unchanged through 2080 in all considered scenarios. In contrast, P. t. ellioti in central Cameroon, which represents half of the population of this subspecies, is expected to experience drastic reductions in its ecotone habitat over the coming century.
    • Do large birds experience previously undetected levels of hunting pressure in the forests of Central and West Africa?

      Whytock, Robin C.; Buij, Ralph; Virani, Munir Z.; Morgan, Bethan J. (2016)
      ...Village-based surveys of hunter offtake and surveys of bushmeat markets have shown that mammals and reptiles are affected most, followed by birds. However, hunters also consume some animals in forest camps and these may have been overlooked in surveys that have focused on bushmeat extracted from the forest....
    • Genetic signatures of a demographic collapse in a large-bodied forest dwelling primate (Mandrillus leucophaeus)

      Ting, Nelson; Astaras, Christos; Hearn, Gail; Honarvar, Shaya; Corush, Joel; Burrell, Andrew S.; Phillips, Naomi; Morgan, Bethan J.; Gadsby, Elizabeth L.; Raaum, Ryan; et al. (2012)
      It is difficult to predict how current climate change will affect wildlife species adapted to a tropical rainforest environment. Understanding how population dynamics fluctuated in such species throughout periods of past climatic change can provide insight into this issue. The drill (Mandrillus leucophaeus) is a large-bodied rainforest adapted mammal found in West Central Africa. In the middle of this endangered monkey's geographic range is Lake Barombi Mbo, which has a well-documented palynological record of environmental change that dates to the Late Pleistocene. We used a Bayesian coalescent-based framework to analyze 2,076 base pairs of mitochondrial DNA across wild drill populations to infer past changes in female effective population size since the Late Pleistocene. Our results suggest that the drill underwent a nearly 15-fold demographic collapse in female effective population size that was most prominent during the Mid Holocene (approximately 3-5 Ka). This time period coincides with a period of increased dryness and seasonality across Africa and a dramatic reduction in forest coverage at Lake Barombi Mbo. We believe that these changes in climate and forest coverage were the driving forces behind the drill population decline. Furthermore, the warm temperatures and increased aridity of the Mid Holocene are potentially analogous to current and future conditions faced by many tropical rainforest communities. In order to prevent future declines in population size in rainforest-adapted species such as the drill, large tracts of forest should be protected to both preserve habitat and prevent forest loss through aridification.
    • Regional Action Plan for the Conservation of the Nigeria-Cameroon Chimpanzee (Pan troglodytes ellioti)

      Morgan, Bethan J.; Adeleke, Alade; Bassey, Tony; Bergl, Richard; Dunn, Andrew; Fotso, Roger; Gadsby, Elizabeth; Gonder, Mary Katherine; Greengrass, Elisabeth; Koulagna, Denis Koutou; et al. (IUCN/SSC Primate Specialist Group and Zoological Society of San Diego, 2011)
      This document represents the consensus of views from forestry and wildlife conservation agencies in Nigeria and Cameroon, local and international nongovernmental conservation organizations, and university-based researchers who met at a series of workshops in Cameroon and Nigeria to formulate a set of actions that, if implemented, will increase the long-term survival prospects of the Nigeria-Cameroon chimpanzee.
    • Regional Action Plan for the Conservation of the Nigeria–Cameroon Chimpanzee (Pan troglodytes ellioti)

      Morgan, Bethan J.; Adeleke, Alade; Bassey, Tony; Bergl, Richard; Dunn, Andrew; Fotso, Roger; Gadsby, Elizabeth; Gonder, Mary Katherine; Greengrass, Elisabeth; Koulagna, Denis Koutou; et al. (IUCN/SSC Primate Specialist Group and Zoological Society of San Diego, 2011)
      This document represents the consensus of views from forestry and wildlife conservation agencies in Nigeria and Cameroon, local and international nongovernmental conservation organizations, and university-based researchers who met at a series of workshops in Cameroon and Nigeria to formulate a set of actions that, if implemented, will increase the longterm survival prospects of the Nigeria-Cameroon chimpanzee, Pan troglodytes ellioti. The Nigeria-Cameroon chimpanzee is the most endangered of all currently recognized chimpanzee subspecies, with a total remaining population of between 3,500 and 9,000 living in forested habitat to the north of the Sanaga River in Cameroon, the eastern edge of Nigeria, and in forest fragments in the Niger Delta and southwestern Nigeria
    • Revised Regional Action Plan for the Conservation of the Cross River Gorilla (Gorilla gorilla diehli) 2014–2019

      Dunn, Andrew; Bergl, Richard; Byler, Dirck; Eben-Ebai, Samuel; Etiendem, Denis Ndeloh; Fotso, Roger; Ikfuingei, Romanus; Imong, Inaoyom; Jameson, Chris; Macfie, Elizabeth J.; et al. (IUCN/SSC Primate Specialist Group and Wildlife Conservation SocietyNew York, NY, USA, 2014)
      This plan outlines measures that should ensure that Cross River gorilla numbers are able to increase at key core sites, allowing them to extend into areas where they have been absent for many years.
    • The population genetics of wild chimpanzees in Cameroon and Nigeria suggests a positive role for selection in the evolution of chimpanzee subspecies

      Mitchell, Matthew W.; Locatelli, Sabrina; Ghobrial, Lora; Pokempner, Amy A.; Sesink Clee, Paul R.; Abwe, Ekwoge E.; Nicholas, Aaron; Nkembi, Louis; Anthony, Nicola M.; Morgan, Bethan J.; et al. (2015)
      Chimpanzees (Pan troglodytes) can be divided into four subspecies. Substantial phylogenetic evidence suggests that these subspecies can be grouped into two distinct lineages: a western African group that includes P. t. verus and P. t. ellioti and a central/eastern African group that includes P. t. troglodytes and P. t. schweinfurthii. The geographic division of these two lineages occurs in Cameroon, where the rages of P. t. ellioti and P. t. troglodytes appear to converge at the Sanaga River. Remarkably, few population genetic studies have included wild chimpanzees from this region.