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Average wildlife harvesting rates of large mammals (>1 kilogram adult body mass) in tropical forests are about 6.0 animals per square kilometer per year in
Southeast Asia (2 studies), 17.5 animals in Africa (2 studies), and 8.1 animals in Latin America (5 studies) according to data derived from J. Robinson and E. Bennett, Eds., Hunting for Sustainability in Tropical Forests (Columbia University Press, New York, 1999). Chart and photo of a young gorilla in Gabon by Rhett A. Butler.
These rough estimates, showing that millions of animals are killed each year in Africa, Asia, and the Amazon for subsistence hunting and the bushmeat trade, are extrapolated from J. Robinson and E. Bennett (1999) data, forest cover figures from the U.N. Food and Agricultural Organization for 2005, and numbers in J. Robinson and K. Redford, Eds., Neotropical Wildlife Use and Conservation (University of Chicago Press, Chicago, IL, 1991);. The numbers include mammals, birds, and reptiles. Estimation, chart and photo of a red howler monkey in Colombia by Rhett A. Butler. Please note that these are only rudimentary estimates -- there are presently no reliable projections for the number of animals hunted each year.
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The wildlife harvest takes a staggering number of animals: every year in the Brazilian Amazon alone, where 9.6 to 23.5 million mammals, birds, and reptiles are harvested. The annual harvest in the tropical forests of Africa may be 6-12 times that amount, since
Wreathed Hornbill (Rhyticeros undulatus). Hornbills are important seed dispersers in many forests yet they are often targeted by hunters. Click image for more photos of hornbills. (Photo by R. Butler)
Review questions
:
- Why are tigers endangered?
- How can alien or invasive species impact the environment?
Continued / Next: Unsustainable tourism
Davis, K. ("Goodall: Illegal Hunting is Biggest Threat to Chimpanzees" A.P. 12/10/97) and McRae, M. ("Road Kill in Cameroon." Natural History. Vol. 107, No. 1, Feb 1997.) provides an overview of the African bushmeat trade.
Wildlife harvesting in logged tropical forests is surveyed in Robinson, J.G. et al. "Wildlife harvest in logged tropical forests," Science Vol. 284 (5415): 595, 1999
In "Strapped for Cash, Asians Plunder their Forests and Endanger their Future," Effects of the Asian Economic Crisis series, AsiaPacific Issues No. 39, April 1999, Donovan examines the effect of the Asian economic recession on wildlife harvest and concludes that the depressed market conditions spurred an increase in hunting and wildlife collection.
Epstein, J. ("For sale: creatures great and small," SF Chronicle 10-7-99) and Saunders, J. ("S.African Police Crack Reptile Smuggling Syndicate," Reuters 10/20/97) explore the illegal pet trade.
James, H.F. and S.L. Olson ("Descriptions of thirty-two species of birds from the Hawaiian Islands: part II. Passeriformes," Ornithology Monogr. 46:1-88, 1991) note that 62 bird species have gone extinct since the arrival of the Polynesians in the Hawaiian islands.
According to Wagner, W.L., Herbst, D.R., Sohmer, S.H., in Manual of the Flowering Plants of Hawaii, Honolulu: University of Hawaii Press and Bishop Museum Press, 1990, today Hawaii has more alien plant species than native ones.