Browsing by Author "Greengrass, E"

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    Assessing Africa-Wide Pangolin Exploitation by Scaling Local Data
    (Conservation Letters, 2018-03) Ingram, DJ; Coad, L; Abernethy, KA; Maisels, F; Stokes, EJ; Bobo, KS; Breuer, T; Gandiwa, E; Ghiurghi, A; Greengrass, E; Holmern, T; Kamgaing, TOW; Ndong Obiang, AM; Poulsen, JR; Schleicher, J; Nielsen, MR; Solly, H; Vath, CL; Waltert, M; Whitham, CEL; Wilkie, DS; Scharlemann, JPW
    Copyright and Photocopying: © 2017 The Authors. Conservation Letters published by Wiley Periodicals, Inc. Overexploitation is one of the main pressures driving wildlife closer to extinction, yet broad-scale data to evaluate species’ declines are limited. Using African pangolins (Family: Pholidota) as a case study, we demonstrate that collating local-scale data can provide crucial information on regional trends in exploitation of threatened species to inform conservation actions and policy. We estimate that 0.4-2.7 million pangolins are hunted annually in Central African forests. The number of pangolins hunted has increased by ∼150% and the proportion of pangolins of all vertebrates hunted increased from 0.04% to 1.83% over the past four decades. However, there were no trends in pangolins observed at markets, suggesting use of alternative supply chains. The price of giant (Smutsia gigantea) and arboreal (Phataginus sp.) pangolins in urban markets has increased 5.8 and 2.3 times respectively, mirroring trends in Asian pangolins. Efforts and resources are needed to increase law enforcement and population monitoring, and investigate linkages between subsistence hunting and illegal wildlife trade.
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    Impact of simian immunodeficiency virus infection on chimpanzee population dynamics.
    (PLoS Pathog, 2010-09-23) Rudicell, RS; Jones, JH; Wroblewski, EE; Learn, GH; Li, Y; Robertson, JD; Greengrass, E; Grossmann, F; Kamenya, S; Pintea, L; Mjungu, DC; Lonsdorf, EV; Mosser, A; Lehman, C; Collins, DA; Keele, BF; Goodall, J; Hahn, BH; Pusey, AE; Wilson, ML
    Like human immunodeficiency virus type 1 (HIV-1), simian immunodeficiency virus of chimpanzees (SIVcpz) can cause CD4+ T cell loss and premature death. Here, we used molecular surveillance tools and mathematical modeling to estimate the impact of SIVcpz infection on chimpanzee population dynamics. Habituated (Mitumba and Kasekela) and non-habituated (Kalande) chimpanzees were studied in Gombe National Park, Tanzania. Ape population sizes were determined from demographic records (Mitumba and Kasekela) or individual sightings and genotyping (Kalande), while SIVcpz prevalence rates were monitored using non-invasive methods. Between 2002-2009, the Mitumba and Kasekela communities experienced mean annual growth rates of 1.9% and 2.4%, respectively, while Kalande chimpanzees suffered a significant decline, with a mean growth rate of -6.5% to -7.4%, depending on population estimates. A rapid decline in Kalande was first noted in the 1990s and originally attributed to poaching and reduced food sources. However, between 2002-2009, we found a mean SIVcpz prevalence in Kalande of 46.1%, which was almost four times higher than the prevalence in Mitumba (12.7%) and Kasekela (12.1%). To explore whether SIVcpz contributed to the Kalande decline, we used empirically determined SIVcpz transmission probabilities as well as chimpanzee mortality, mating and migration data to model the effect of viral pathogenicity on chimpanzee population growth. Deterministic calculations indicated that a prevalence of greater than 3.4% would result in negative growth and eventual population extinction, even using conservative mortality estimates. However, stochastic models revealed that in representative populations, SIVcpz, and not its host species, frequently went extinct. High SIVcpz transmission probability and excess mortality reduced population persistence, while intercommunity migration often rescued infected communities, even when immigrating females had a chance of being SIVcpz infected. Together, these results suggest that the decline of the Kalande community was caused, at least in part, by high levels of SIVcpz infection. However, population extinction is not an inevitable consequence of SIVcpz infection, but depends on additional variables, such as migration, that promote survival. These findings are consistent with the uneven distribution of SIVcpz throughout central Africa and explain how chimpanzees in Gombe and elsewhere can be at equipoise with this pathogen.
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    Synthesising bushmeat research effort in West and Central Africa: A new regional database
    (Biological Conservation, 2015-01-01) Taylor, G; Scharlemann, JPW; Rowcliffe, M; Kümpel, N; Harfoot, MBJ; Fa, JE; Melisch, R; Milner-Gulland, EJ; Bhagwat, S; Abernethy, KA; Ajonina, AS; Albrechtsen, L; Allebone-Webb, S; Brown, E; Brugiere, D; Clark, C; Colell, M; Cowlishaw, G; Crookes, D; De Merode, E; Dupain, J; East, T; Edderai, D; Elkan, P; Gill, D; Greengrass, E; Hodgkinson, C; Ilambu, O; Jeanmart, P; Juste, J; Linder, JM; Macdonald, DW; Noss, AJ; Okorie, PU; Okouyi, VJJ; Pailler, S; Poulsen, JR; Riddell, M; Schleicher, J; Schulte-Herbrüggen, Björn; Starkey, M; van Vliet, N; Whitham, C; Willcox, AS; Wilkie, DS; Wright, JH; Coad, LM
    © 2014 Elsevier Ltd. Unsustainable hunting threatens both biodiversity and local livelihoods. Despite high levels of research effort focused on understanding the dynamics of bushmeat trade and consumption, current research is largely site specific. Without synthesis and quantitative analysis of available case studies, the national and regional characteristics of bushmeat trade and consumption remain largely speculative, impeding efforts to inform national and regional policy on bushmeat trade. Here we describe the structure and content of the West and Central African bushmeat database which holds quantitative data on bushmeat sales, consumption and offtake for 177 species from 275 sites across 11 countries in two regions, spanning three decades of research. Despite this wealth of available data, we found important biases in research effort. The majority of studies in West and Central Africa have collected market data, which although providing a useful record of bushmeat sales, are limited in their ability to track changes in hunting offtake. In addition, few data exist for West Africa, and few studies have tracked changes over time, using repeat sampling. With new initiatives in the regions to track bushmeat hunting, this database represents an opportunity to synthesise current and future data on bushmeat hunting, consumption and trade in West and Central Africa, identify gaps in current understanding, and systematically target future monitoring efforts.