ABSTRACT Stable isotope data from durable, sequentially grown tissues (e.g. hair, claw, and baleen) is commonly used for modelling dietary niche breadth. The use of tissues grown over multiple months to years, however, has the potential to complicate isotopic niche breadth modelling, as time-averaged stable isotope signals from whole tissues may obscure information available from chronologically resolved stable isotope signals in serially sectioned tissues. We determined if whole samples of brown bear guard hair produced different isotopic niche breadth estimates than those produced from subsampled, serially sectioned samples of the same tissue from the same set of individuals. We sampled guard hair from brown bears (Ursus arctos) in four regions of Alaska with disparate biogeographies and dietary resource availability. Whole hair and serially sectioned hair samples were used to produce paired isotopic dietary niche breadth estimates for each region in the SIBER Bayesian model framework in R. Isotopic data from serially sectioned hair consistently produced larger estimates of isotopic dietary niche breadth than isotope data from whole hair samples. Serial sampling captures finer-scale changes in diet and when cumulatively used to estimate isotopic niche breadth, the serially sampled isotope data more fully captures dietary variability and true isotopic niche breadth.

中文翻译：

---

分裂毛发：使用连续生长组织的稳定同位素分析进行​​饮食生态位宽度建模

摘要 来自耐用、连续生长的组织（例如头发、爪子和鲸须）的稳定同位素数据通常用于对饮食生态位宽度进行建模。然而，使用生长数月至数年的组织有可能使同位素生态位宽度建模复杂化，因为来自整个组织的时间平均稳定同位素信号可能会掩盖从连续切片组织中按时间顺序解析的稳定同位素信号可用的信息。我们确定整个棕熊护毛样本是否产生了不同的同位素生态位宽度估计值，与从同一组个体的同一组织的子采样、连续切片样本中产生的那些估计值是否不同。我们在阿拉斯加的四个地区采集了棕熊 (Ursus arctos) 的护毛样本，这些地区具有不同的生物地理和饮食资源可用性。全头发和连续切片的头发样本用于为 R 中 SIBER 贝叶斯模型框架中的每个区域生成配对的同位素饮食生态位宽度估计值。 连续切片头发的同位素数据始终比全头发的同位素数据产生更大的同位素饮食生态位宽度估计值样品。连续采样捕获饮食中更精细的变化，当累积用于估计同位素生态位宽度时，连续采样的同位素数据更全面地捕获饮食变异性和真正的同位素生态位宽度。来自连续切片头发的同位素数据始终比来自全头发样品的同位素数据产生更大的同位素饮食生态位宽度估计值。连续采样捕获饮食中更精细的变化，当累积用于估计同位素生态位宽度时，连续采样的同位素数据更全面地捕获饮食变异性和真正的同位素生态位宽度。来自连续切片头发的同位素数据始终比来自全头发样品的同位素数据产生更大的同位素饮食生态位宽度估计值。连续采样捕获饮食中更精细的变化，当累积用于估计同位素生态位宽度时，连续采样的同位素数据更全面地捕获饮食变异性和真正的同位素生态位宽度。