Resource exploitation and competition for food are important selective pressures in animal evolution. A number of recent investigations have focused on linkages between diversification, trophic morphology and diet in bats, partly because their roosting habits mean that for many bat species diet can be quantified relatively easily through faecal analysis. Dietary analysis in mammals is otherwise invasive, complicated, time consuming and expensive. Here we present evidence from insectivorous bats that analysis of three-dimensional (3-D) textures of tooth microwear using International Organization for Standardization (ISO) roughness parameters derived from sub-micron surface data provides an additional, powerful tool for investigation of trophic resource exploitation in mammals. Our approach, like scale-sensitive fractal analysis, offers considerable advantages over two-dimensional (2-D) methods of microwear analysis, including improvements in robustness, repeatability and comparability of studies. Our results constitute the first analysis of microwear textures in carnivorous mammals based on ISO roughness parameters. They demonstrate that the method is capable of dietary discrimination, even between cryptic species with subtly different diets within trophic guilds, and even when sample sizes are small. We find significant differences in microwear textures between insectivore species whose diet contains different proportions of ‘hard’ prey (such as beetles) and ‘soft’ prey (such as moths), and multivariate analyses are able to distinguish between species with different diets based solely on their tooth microwear textures. Our results show that, compared with previous 2-D analyses of microwear in bats, ISO roughness parameters provide a much more sophisticated characterization of the nature of microwear surfaces and can yield more robust and subtle dietary discrimination. ISO-based textural analysis of tooth microwear thus has a useful role to play, complementing existing approaches, in trophic analysis of mammals, both extant and extinct.

中文翻译：

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通过食虫哺乳动物牙齿微磨损的 3D 纹理分析得出的行会内饮食歧视


资源开发和食物竞争是动物进化中重要的选择压力。最近的许多研究都集中在蝙蝠的多样化、营养形态和饮食之间的联系，部分原因是它们的栖息习性意味着对于许多蝙蝠物种来说，饮食可以通过粪便分析相对容易地量化。否则，哺乳动物的饮食分析是侵入性的、复杂的、耗时且昂贵的。在这里，我们提供来自食虫蝙蝠的证据，表明使用国际标准化组织 (ISO) 源自亚微米表面数据的粗糙度参数对牙齿微磨损的三维 (3-D) 纹理进行分析，为研究营养资源提供了额外的强大工具对哺乳动物的剥削。我们的方法（如尺度敏感分形分析）比二维 (2-D) 微磨损分析方法具有相当大的优势，包括研究的稳健性、可重复性和可比性方面的改进。我们的结果构成了基于 ISO 粗糙度参数的肉食哺乳动物微磨损纹理的首次分析。他们证明，该方法能够进行饮食区分，甚至在营养行会内饮食略有不同的神秘物种之间，甚至在样本量很小的情况下也是如此。我们发现饮食中含有不同比例的“硬”猎物（如甲虫）和“软”猎物（如飞蛾）的食虫物种之间的微磨损纹理存在显着差异，并且多变量分析能够仅根据不同饮食来区分具有不同饮食的物种。他们的牙齿微磨损纹理。 我们的结果表明，与之前对蝙蝠微磨损的二维分析相比，ISO 粗糙度参数提供了对微磨损表面性质的更复杂的表征，并且可以产生更强大和微妙的饮食歧视。因此，基于 ISO 的牙齿微磨损纹理分析在对现存和灭绝的哺乳动物的营养分析中可以发挥有用的作用，补充现有的方法。