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Long-Term Urban Market Dynamics Reveal Increased Bushmeat Carcass Volume despite Economic Growth and Proactive Environmental Legislation on Bioko Island, Equatorial Guinea.

Cronin DT, Woloszynek S, Morra WA, Honarvar S, Linder JM, Gonder MK, O'Connor MP, Hearn GW - PLoS ONE (2015)

Bottom Line: Attempts to limit bushmeat sales, including a 2007 ban on primate hunting and trade, were only transiently effective.The hunting ban was not enforced, and was quickly followed by a marked increase in bushmeat hunting compared to hunting rates prior to the ban.Our results emphasize the negative impact that rapid development and unenforced legislation have had on Bioko's wildlife, and demonstrate the need for strong governmental support if conservation strategies are to be successful at preventing extinctions of tropical wildlife.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Drexel University, Philadelphia, Pennsylvania, United States of America; Department of Biodiversity, Earth and Environmental Science, Drexel University, Philadelphia, Pennsylvania, United States of America; Bioko Biodiversity Protection Program, Malabo, Bioko Norte, Equatorial Guinea.

ABSTRACT
Bushmeat hunting is extensive in west and central Africa as both a means for subsistence and for commercial gain. Commercial hunting represents one of the primary threats to wildlife in the region, and confounding factors have made it challenging to examine how external factors influence the commercial bushmeat trade. Bioko Island, Equatorial Guinea is a small island with large tracts of intact forest that support sizeable populations of commercially valuable vertebrates, especially endemic primates. The island also has a low human population and has experienced dramatic economic growth and rapid development since the mid-1990's. From October 1997 - September 2010, we monitored the largest bushmeat market on Bioko in Malabo, recording over 197,000 carcasses for sale. We used these data to analyze the dynamics of the market in relation to political events, environmental legislation, and rapid economic growth. Our findings suggest that bushmeat hunting and availability increased in parallel with the growth of Equatorial Guinea's GDP and disposable income of its citizens. During this 13-year study, the predominant mode of capture shifted from trapping to shotguns. Consequently, carcass volume and rates of taxa typically captured with shotguns increased significantly, most notably including intensified hunting of Bioko's unique and endangered monkey fauna. Attempts to limit bushmeat sales, including a 2007 ban on primate hunting and trade, were only transiently effective. The hunting ban was not enforced, and was quickly followed by a marked increase in bushmeat hunting compared to hunting rates prior to the ban. Our results emphasize the negative impact that rapid development and unenforced legislation have had on Bioko's wildlife, and demonstrate the need for strong governmental support if conservation strategies are to be successful at preventing extinctions of tropical wildlife.

No MeSH data available.


Primate carcass rates raw data, fitted, and predicted values.Values are as estimated in the intervention analysis via ARIMA (2,0,0,)x(1,0,0)12. Significant interventions are numbered at: 1) 2/1998 –political uprising; 2) 3/2002 –bushmeat roundtable; 3) 11/2003 –Law 7/2003; 4) 11/2007 –Decree 72/2007.
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pone.0134464.g003: Primate carcass rates raw data, fitted, and predicted values.Values are as estimated in the intervention analysis via ARIMA (2,0,0,)x(1,0,0)12. Significant interventions are numbered at: 1) 2/1998 –political uprising; 2) 3/2002 –bushmeat roundtable; 3) 11/2003 –Law 7/2003; 4) 11/2007 –Decree 72/2007.

Mentions: The pre-intervention SARIMA model consisted of a second order autoregressive term (ϕ = 0.343 (SE = 0.078) and 0.301 (0.078)) and a first order seasonal autoregressive term with period 12 (0.208 (0.084)): ARIMA(2, 0, 0)x(1, 0, 0)12. The model indicated that four out of the five notable events during the study period significantly altered market dynamics (RMSE 0.323; AIC 115.03) (Table 1; Fig 3). Intervention 2/1998 consisted of only a downward pulse, a momentary deviation that rapidly returned to baseline; whereas, 3/2002 and 11/2003 began as a downward pulse, but were followed by a step, a permanent shift in the mean of the series. The primate hunting ban was the most dramatic market intervention, decreasing the primate carcass rate by 87.81% (95% CI: 79.75, 95.88) between October and November 2007 (Fig 3) via an initial pulse. Its time lag parameter, beginning at a local minimum caused by the pulse function, determines the number of time steps required to reach the significantly increased mean carcass rate at the end of the series, determined by the step function; that is, the lag accounts for the gradual increase in primate carcass rates from11/2007 through 9/2010 (Table 1; Fig 3).


Long-Term Urban Market Dynamics Reveal Increased Bushmeat Carcass Volume despite Economic Growth and Proactive Environmental Legislation on Bioko Island, Equatorial Guinea.

Cronin DT, Woloszynek S, Morra WA, Honarvar S, Linder JM, Gonder MK, O'Connor MP, Hearn GW - PLoS ONE (2015)

Primate carcass rates raw data, fitted, and predicted values.Values are as estimated in the intervention analysis via ARIMA (2,0,0,)x(1,0,0)12. Significant interventions are numbered at: 1) 2/1998 –political uprising; 2) 3/2002 –bushmeat roundtable; 3) 11/2003 –Law 7/2003; 4) 11/2007 –Decree 72/2007.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4521855&req=5

pone.0134464.g003: Primate carcass rates raw data, fitted, and predicted values.Values are as estimated in the intervention analysis via ARIMA (2,0,0,)x(1,0,0)12. Significant interventions are numbered at: 1) 2/1998 –political uprising; 2) 3/2002 –bushmeat roundtable; 3) 11/2003 –Law 7/2003; 4) 11/2007 –Decree 72/2007.
Mentions: The pre-intervention SARIMA model consisted of a second order autoregressive term (ϕ = 0.343 (SE = 0.078) and 0.301 (0.078)) and a first order seasonal autoregressive term with period 12 (0.208 (0.084)): ARIMA(2, 0, 0)x(1, 0, 0)12. The model indicated that four out of the five notable events during the study period significantly altered market dynamics (RMSE 0.323; AIC 115.03) (Table 1; Fig 3). Intervention 2/1998 consisted of only a downward pulse, a momentary deviation that rapidly returned to baseline; whereas, 3/2002 and 11/2003 began as a downward pulse, but were followed by a step, a permanent shift in the mean of the series. The primate hunting ban was the most dramatic market intervention, decreasing the primate carcass rate by 87.81% (95% CI: 79.75, 95.88) between October and November 2007 (Fig 3) via an initial pulse. Its time lag parameter, beginning at a local minimum caused by the pulse function, determines the number of time steps required to reach the significantly increased mean carcass rate at the end of the series, determined by the step function; that is, the lag accounts for the gradual increase in primate carcass rates from11/2007 through 9/2010 (Table 1; Fig 3).

Bottom Line: Attempts to limit bushmeat sales, including a 2007 ban on primate hunting and trade, were only transiently effective.The hunting ban was not enforced, and was quickly followed by a marked increase in bushmeat hunting compared to hunting rates prior to the ban.Our results emphasize the negative impact that rapid development and unenforced legislation have had on Bioko's wildlife, and demonstrate the need for strong governmental support if conservation strategies are to be successful at preventing extinctions of tropical wildlife.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, Drexel University, Philadelphia, Pennsylvania, United States of America; Department of Biodiversity, Earth and Environmental Science, Drexel University, Philadelphia, Pennsylvania, United States of America; Bioko Biodiversity Protection Program, Malabo, Bioko Norte, Equatorial Guinea.

ABSTRACT
Bushmeat hunting is extensive in west and central Africa as both a means for subsistence and for commercial gain. Commercial hunting represents one of the primary threats to wildlife in the region, and confounding factors have made it challenging to examine how external factors influence the commercial bushmeat trade. Bioko Island, Equatorial Guinea is a small island with large tracts of intact forest that support sizeable populations of commercially valuable vertebrates, especially endemic primates. The island also has a low human population and has experienced dramatic economic growth and rapid development since the mid-1990's. From October 1997 - September 2010, we monitored the largest bushmeat market on Bioko in Malabo, recording over 197,000 carcasses for sale. We used these data to analyze the dynamics of the market in relation to political events, environmental legislation, and rapid economic growth. Our findings suggest that bushmeat hunting and availability increased in parallel with the growth of Equatorial Guinea's GDP and disposable income of its citizens. During this 13-year study, the predominant mode of capture shifted from trapping to shotguns. Consequently, carcass volume and rates of taxa typically captured with shotguns increased significantly, most notably including intensified hunting of Bioko's unique and endangered monkey fauna. Attempts to limit bushmeat sales, including a 2007 ban on primate hunting and trade, were only transiently effective. The hunting ban was not enforced, and was quickly followed by a marked increase in bushmeat hunting compared to hunting rates prior to the ban. Our results emphasize the negative impact that rapid development and unenforced legislation have had on Bioko's wildlife, and demonstrate the need for strong governmental support if conservation strategies are to be successful at preventing extinctions of tropical wildlife.

No MeSH data available.