Using measurements of naturally occurring stable isotopes in feathers to determine avian origin and migratory patterns is well established. However, isotopically determining nutritional origins of lipids, a major migratory fuel, has not been attempted. This study explores isotopic links between diet and stored lipids in captive white-throated sparrows (Zonotrichia albicollis) by providing isotopically distinct mixtures of carbohydrates/oils and drinking water and assessing the δ¹³C and δ²H values of stored lipid, breath CO₂ (δ¹³C) and breath water vapour (δ²H). Stored lipid δ¹³C and δ²H values correlated with the isotopic values found in dietary carbohydrates/oils and drinking water treatments, respectively, indicating a clear traceable transfer of environmental dietary isotopic signals into body lipids. Dietary oils and carbohydrates contributed 80–82% of carbon and 44–46% of hydrogen, respectively, to stored lipids. Drinking water contributed 18–28% of hydrogen to stored lipids. Isotopic relationships were quantifiable using linear calibration algorithms which provide the basis for the construction of tissue isoscapes for migratory passerines. Breath CO₂ δ¹³C values and breath water vapour δ²H values for fed and fasted birds reflected dietary sources. Breath CO₂ δ¹³C values were higher for fasted birds than for fed birds by an average of 4.5‰ while breath water vapour δ²H values were lower for fasted birds by an average of 48.9‰. These results indicate that lipids and metabolites from their subsequent breakdown for fuel isotopically reflect dietary sources but complicate interpretation of such data, especially for wild migrating birds. Applications and limitations of these findings to the creation of “liposcapes” are examined.

使用羽毛中天然存在的稳定同位素的测量结果来确定禽类起源和迁徙模式已经很成熟。但是，尚未尝试通过同位素确定脂质（一种主要的迁徙燃料）的营养来源。本研究探讨（饮食和圈养白喉麻雀存储脂质之间同位素链接Zonotrichia albicollis）通过提供碳水化合物/油的同位素不同的混合物和饮用水并评估δ ¹³ C和δ ^2个存储脂质h的值，呼吸CO ₂（δ ¹³ C）和呼吸水蒸气（δ ² H）。存储脂质δ ¹³ C和δ ²与同位素值相关联ħ值中的膳食的碳水化合物/油和饮用水处理分别发现，指示环境膳食同位素信号的清晰可追踪转移入体的脂质。膳食油和碳水化合物分别为储存的脂质贡献了80-82％的碳和44-46％的氢。饮用水为储存的脂质贡献了18-28％的氢。同位素关系可以使用线性校准算法进行定量，该线性校准算法为迁徙雀形目的组织等景线的构建提供了基础。呼吸CO ₂ δ ¹³ C值和呼吸水蒸气δ ^2个ħ值进食和禁食鸟类反射膳食来源。呼吸CO ₂ δ^13个C值由平均4.5‰同时呼气水蒸气分别为禁食鸟类比馈送鸟类更高δ ^2个ħ值平均为48.9‰分别为禁食鸟类更低。这些结果表明，脂质和代谢物随后分解为燃料的同位素反映了饮食来源，但使此类数据的解释复杂化，尤其是对于野生迁徙鸟类。这些发现的应用和局限性被创造出来。