College of Wildlife Resources, Northeast Forestry University, No. 26, Hexing Road, Xiangfang District, Harbin 150040, China.
Forensic Sci Int. 2011 Apr 15;207(1-3):61-5. doi: 10.1016/j.forsciint.2010.09.001. Epub 2010 Oct 8.
Wildlife has been utilized by humans throughout history and demand continues to grow today. Farming of wildlife can supplement the supply of wild-harvested wildlife products and, in theory, can reduce pressure on free-ranging populations. However, poached wildlife products frequently enter legal markets where they are fraudulently sold as farmed wildlife products. To effectively close this illegal trade in wild-captured wildlife, there is a need to discriminate wild products from farmed products. Because of the strong market demand for wild-captured frog meat and the resulting strong downward pressure on wild populations, we undertook research to develop a method to discriminate wild from farmed Dybowski's frog (Rana dybowskii) based on femur bone density. We measured femur bone density (D(f)) as the ratio of bone mass to bone volume. D(f) of wild frogs revealed a slightly increasing linear trend with increasing age (R(2)=0.214 in males and R(2)=0.111 in females, p=0.000). Wild males and wild females of age classes from 2 to ≥ 5 years had similar D(f) values. In contrast, 2-year-old farmed frogs showed significantly higher D(f) values (p=0.000) among males (mean D(f)=0.623 ± 0.011 g/ml, n=32) than females (mean D(f)=0.558 ± 0.011 g/ml, n=27). For both sexes, D(f) of wild frogs was significantly higher than that of farmed frogs (p=0.000). Among males, 87.5% (28 of 32 individuals) of farmed frogs were correctly identified as farmed frogs and 86.3% (69 of 80 individuals) of wild frogs were correctly identified as wild frogs. These results suggest that femur bone density is one reliable tool for discriminating between wild and farmed Dybowski's frog. This study also highlights a novel strategy with explicit forensic potential to discriminate wild from captive bred wildlife species.
野生动物在历史上一直被人类利用，如今的需求仍在不断增长。野生动物养殖可以补充野生采集野生动物产品的供应，并且从理论上讲可以减轻对自由放养种群的压力。但是，偷猎的野生动物产品经常进入合法市场，在这些市场中，它们被欺诈性地作为养殖野生动物产品出售。为了有效制止这种非法的野生捕获野生动物贸易，有必要区分野生产品和养殖产品。由于对野生捕获的青蛙肉的强烈市场需求以及对野生种群的强烈下行压力，我们着手研究开发一种基于股骨骨密度区分野生和养殖杜氏蛙（Rana dybowskii）的方法。我们将股骨骨密度（D(f)）测量为骨量与骨体积的比值。野生青蛙的 D(f)随着年龄的增长呈现出略微增加的线性趋势（雄性的 R(2)=0.214，雌性的 R(2)=0.111，p=0.000）。年龄在 2 至≥5 岁的野生雄性和野生雌性的 D(f)值相似。相比之下，2 岁的养殖青蛙的 D(f)值明显更高（p=0.000），雄性的平均值 D(f)=0.623±0.011 g/ml，n=32）高于雌性（平均值 D(f)=0.558±0.011 g/ml，n=27）。对于雌雄两性，野生青蛙的 D(f)均明显高于养殖青蛙（p=0.000）。在雄性中，87.5%（32 个个体中的 28 个）的养殖青蛙被正确识别为养殖青蛙，86.3%（80 个个体中的 69 个）的野生青蛙被正确识别为野生青蛙。这些结果表明，股骨骨密度是区分杜氏蛙野生和养殖的可靠工具之一。本研究还突出了一种具有明确法医学潜力的新颖策略，可用于区分野生动物和人工饲养的野生动物物种。
