A comparison of scat-analysis methods to assess the diet of the wolf Canis lupus
A comparison of scat-analysis methods to assess the diet of the wolf Canis lupus
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DOI：
10.2981/wlb.1996.006
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发表时间：
1996-01-01
期刊：
影响因子：
1.9
通讯作者：
Guy, Ilaria
中科院分区：
文献类型：
--
作者：
Ciucci, Paolo;Boitani, Luigi;Guy, Ilaria
对六种粪便分析方法进行了比较和测试，以对意大利北部亚平宁山脉的狼饮食进行差异评估。使用标准化实验室技术对 217 只狼粪便样本进行分析，并根据以下饮食测量对回收的未消化残留物进行量化：出现频率、干重（估计和测量）、相对体积和摄入的生物量（两种方法）。除其中一种生物质方法外，所检查的程序之间没有显着的分歧。然而，不同方法的排名之间的一些差异表明了应考虑的偏差来源，以避免误导性结论。可以纠正频率数据以减少一些相关形式的偏差，而按重量和体积排名似乎受到未消化残留物结构的影响。尽管程度不同，但所有根据未消化残留物的直接测量（即按频率、重量和体积）对食物进行排序的方法都会受到不同猎物尺寸的表面积与体积比偏差的影响。线性回归生物量模型可以纠正表面/体积偏差，但应用它们时存在一些缺点，并且仅限于哺乳动物猎物。生物量模型的适用性应根据饮食成分和猎物大小进行评估，并与其他现场收集的信息相结合仔细解释结果。通过比较两种或多种方法获得的结果，将大大增强对粪便分析数据的解释，以评估狼以及其他食肉动物的饮食。
Six scat-analysis methods were compared and tested for differential assessment of a wolf Canis lupus diet in the Northern Apennine Mountains, Italy. A sample of 217 wolf scats was analysed using standardised laboratory techniques, and the recovered undigested remains were quantified according to the following diet measurements: frequency of occurrence, dry weight (estimated and measured), relative volume, and biomass ingested (two methods). With the exception of one of the biomass methods, there was no significant disagreement between the procedures examined. However, some discrepancies between rankings from different methods indicated the sources of bias that should be accounted for to avoid misleading conclusions. Frequency data can be corrected to reduce some of the associated forms of bias, whereas rankings by weight and volume appear affected by the structure of undigested remains. Although to different extents, all the methods which rank food items according to direct measures of the undigested remains, i.e. by frequency, weight, and volume, suffer from the surface to volume ratio bias of varying prey sizes. Linear-regression biomass models correct for the surface/volume bias, but there are some drawbacks when applying them, and they are limited to mammalian prey. Applicability of the biomass models should be evaluated on the basis of diet composition and prey sizes, and results carefully interpreted in concert with other field-collected information. Interpretation of scat-analysis data in order to assess the diet of wolves, as well as of other carnivores, would be greatly enhanced by comparing results obtained with two or more methods.