THE LONG-TERM EFFECTS OF TIGER POACHING ON POPULATION VIABILITY
THE LONG-TERM EFFECTS OF TIGER POACHING ON POPULATION VIABILITY
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DOI：
10.1046/j.1523-1739.1995.9051116.x-i1
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发表时间：
1995-10-01
影响因子：
6.3
通讯作者：
MCDOUGAL, CW
中科院分区：
文献类型：
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作者：
KENNEY, JS;SMITH, JLD;MCDOUGAL, CW
偷猎老虎，主要是为了它们的骨头，已经成为世界各地野生老虎种群持续存在的最新威胁。传闻表明了这一新威胁的严重性。然而，重要的是要对偷猎行为进行定量分析，作为采取强有力政策行动的基础。因此，我们创建了一个老虎模拟模型，以探讨现实水平的偷猎对种群生存能力的影响。该模型是一个基于个人的随机空间模型，是基于广泛的数据集从尼泊尔皇家奇旺国家公园。我们发现，随着偷猎继续随着时间的推移，种群灭绝的概率增加sigmoidally;存在一个临界区，其中一个小的，增量增加偷猎大大增加灭绝的概率。这意味着偷猎可能一开始不会被视为一种威胁，但可能会突然成为一种威胁。此外，即使偷猎被有效地制止，老虎种群仍然很脆弱，并可能由于人口和环境的随机性而灭绝。我们的模型还表明，偷猎减少了遗传变异，这可能会进一步降低人口的生存能力，由于近亲繁殖的抑郁症。偷猎持续的时间越长，种群就越容易受到这些随机事件的影响。根据目前报告的偷猎率，我们的分析表明，许多野生老虎种群将在20世纪90年代后半期灭绝。
Poaching tigers, primarily for their bones, has become the latest threat to the persistence of wild tiger populations throughout the world. Anecdotal information indicates the seriousness of this new threat. It is important, however, to provide a quantitative analysis of poaching as a basis for strong policy action. We therefore created a tiger simulation model to explore the effects of realistic levels of poaching on population viability. The model is an individually based stochastic spatial model that is based on the extensive data set from Royal Chitwan National Park, Nepal. We found that as poaching continues over time, the probability of population extinction increases sigmoidally; a critical zone exists in which a small, incremental increase in poaching greatly increases the probability of extinction. The implication is that poaching may not at first be seen as a threat but could suddenly become one. Moreover, even if poaching is effectively stopped, tiger populations will still be vulnerable and could go extinct due to demographic and environmental stochasticity. Our model also shows that poaching reduces genetic variability, which could further reduce population viability due to inbreeding depression. The longer poaching is allowed to continue the more vulnerable a population will be to these stochastic events. At currently reported rates of poaching our analysis indicates that many wild tiger populations will be extirpated during the latter half of the 1990s.