Isotopic ecology of coyotes from scat and road kill carcasses: A complementary approach to feeding experiments.
Isotopic ecology of coyotes from scat and road kill carcasses: A complementary approach to feeding experiments.
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DOI：
10.1371/journal.pone.0174897
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Koch PL
中科院分区：
文献类型：
--
作者：
Reid RE;Koch PL
粪便经常被用来研究动物饮食，因为它很容易找到和收集，但一个问题是粪便分析 (GFA) 技术夸大了小型猎物对哺乳动物中捕食者饮食的重要性。为了利用 Scat 的优势，我们建议分析 Scat 碳和氮同位素值（δ13C 和 δ15N）。这项技术为研究人员提供了一种非侵入性的方法来收集短期饮食信息。我们进行了三项相互关联的研究，以验证郊狼粪便中同位素值的使用：1) 我们确定了道路杀伤动物 (n = 4) 郊狼的组织间表观 C 和 N 同位素富集因子（ε13* 和 ε15*）； 2）我们得出土狼的饮食与粪便同位素区分因素； 3）我们使用现场收集的土狼粪便（n = 12）来比较稳定同位素混合模型对土狼饮食比例的估计与两种 GFA 技术的估计。在采样的组织中，Scat 的 δ13C 和 δ15N 值始终最低。我们得出郊狼饮食与粪便的 Δ13C 值为 -1.5‰ ± 1.6‰，Δ15N 值为 2.3‰ ± 1.3‰。土狼粪便 δ13C 和 δ15N 值根据辨别力进行调整，一致地绘制在已知饮食项目创建的同位素混合空间内。与 GFA 结果相比，我们发现土狼饮食比例的混合模型估计低估了小型猎物的重要性。因此，土狼粪便 δ13C 和 δ15N 值提供了一种相对快速且非侵入性的方法来获取准确的饮食信息。
Scat is frequently used to study animal diets because it is easy to find and collect, but one concern is that gross fecal analysis (GFA) techniques exaggerate the importance of small-bodied prey to mammalian mesopredator diets. To capitalize on the benefits of scat, we suggest the analysis of scat carbon and nitrogen isotope values (δ13C and δ15N). This technique offers researchers a non-invasive method to gather short-term dietary information. We conducted three interrelated studies to validate the use of isotopic values from coyote scat: 1) we determined tissue-to-tissue apparent C and N isotope enrichment factors (ε13* and ε15*) for coyotes from road kill animals (n = 4); 2) we derived diet-to-scat isotope discrimination factors for coyotes; and 3) we used field collected coyote scats (n = 12) to compare estimates of coyote dietary proportions from stable isotope mixing models with estimates from two GFA techniques. Scat consistently had the lowest δ13C and δ15N values among the tissues sampled. We derived a diet-to-scat Δ13C value of -1.5‰ ± 1.6‰ and Δ15N value of 2.3‰ ± 1.3‰ for coyotes. Coyote scat δ13C and δ15N values adjusted for discrimination consistently plot within the isotopic mixing space created by known dietary items. In comparison with GFA results, we found that mixing model estimates of coyote dietary proportions de-emphasize the importance of small-bodied prey. Coyote scat δ13C and δ15N values therefore offer a relatively quick and non-invasive way to gain accurate dietary information.