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Dr. John Fa vom Durrell Wildlife Conservation Trust
spricht auf unsere Einladung hin im Biologischen Kolloquium der Uni Bielefeld. Er leitet im Artenschutz-Zoo von Jersey das International Trainings Centre.
Termin: Di., 6. Februar 2001, in Hörsaal 14, 17:15 Uhr. Gäste willkommen!
There is mounting evidence that defaunation of the world's remaining tropical forests is a major cause of biodiversity loss, in some cases more important than deforestation. Forest vertebrates that are hunted for subsistence or commercial purposes are particularly affected. Such forest meat, game meat, or bushmeat, has long been a critical component of the diet of forest dwellers in tropical forest regions, often representing more than half of the animal protein intake. However, continuous offtake of game meat can only be sustained when hunting-induced mortality of target species does not exceed production. Yet, wild meat consumption has become more intensive in many moist tropical forest regions. This is largely because of rapidly increasing human populations, improved hunting technologies and a greater emphasis on commercialisation. Increases in game extraction can aggravate pressures on local faunas, especially on large-bodied forest vertebrates, in some cases driving them to local extinction.
Game hunting is the single most geographically widespread form of resource extraction in South America and Africa, and can affect the core of even the largest and least accessible nature reserves. Studies that have calculated sustainability of game harvests in these continents have almost invariably found that rates of extraction far exceed those of production, even in the case of traditional aborigine societies still using rudimentary hunting technology.Such uncontrolled exploitation will no doubt threaten to bring about marked population declines, and eventually the extinction of a number of game species. Coupled with threats from habitat loss, even from historical deforestation, global extinctions of the most sensitive species such as primates are likely to occur as an accumulation of local disappearances. This may result in long-term changes in tropical forest dynamics through the loss of seed-dispersers, large granivores and frugivores, and "habitat landscapers" such as large forest mammals.
Numerous international conservation organisations believe that tropical forest faunas are seriously endangered from current extraction levels of subsistence and commercial hunting. However, few studies have quantified this at the scale of regions or continents. Such a broader picture would help to understand the extent of the problem and serve to highlight differences and similarities between different geographical areas. Moreover, inter-continental comparisons of consumption and extraction rates can shed light on the interaction between ecosystem productivity, harvestable game biomass and human consumers.
In this talk I will review the patterns of mammalian harvest in tropical moist forests in South America and Africa. I will limit comparisons to these environments to maximise comparability in habitat structure. I will discuss similarities and differences between primary consumer biomass in both continents and estimate the numbers and biomass of game animals harvested each year in the two continents. I will focus on mammals because this class of vertebrates comprises a large proportion of hunting kills in both continents. To that end, I will use data collected from different hunting studies within the major forest blocks in the two regions, the Amazon and Congo Basins.
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