Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, China.
Liziping Giant Panda's Ecology and Conservation Observation and Research Station of Sichuan Province, Nanchong, China.
Integr Zool. 2024 Nov;19(6):1151-1162. doi: 10.1111/1749-4877.12765. Epub 2023 Oct 10.
Trophic niche is the result of the long-term evolution of species and can reflect the pressures they experience in habitats. The whole-genome sequencing of giant pandas (Ailuropoda melanoleuca) has indicated that populations distributed in Qinling (QIN) and non-QIN probably diverged 300 ky ago. Although many studies regarding foraging strategy, habitat preference, and niche partition have been conducted on these populations, there is still a lack of precise quantification of trophic niches. Here, we calculated and compared isotopic trophic niche widths of giant pandas from Sichuan (SC) and QIN populations by measuring carbon and nitrogen isotopes of their hairs; combined with data from sympatric mammals, we explored the relative trophic positions of giant pandas in the ecosystem, respectively. The Stable Isotope Bayesian Ellipses in R (SIBER) model results showed the trophic niche width of QIN pandas was 3.44‰, which was significantly bigger than those of the SC population (2.03‰), with an overlapping about 1.45‰; and they both occupied a unique position in the context, almost one trophic level lower than herbivores. Then, we determined the isotopic ratios of the main foods from the habitats of these pandas; the results suggested that the isotopic difference between bamboo shoots and other parts plus the various feeding selections of pandas on them accounted for pandas' trophic niche widths. We considered the higher nutrition availability and digestible food resources giving QIN pandas a wider trophic niche than pandas from SC. This conclusion provides a new insight into the resource use and trophic ecology of giant pandas and is important to develop refined management plans for the two populations.
营养生态位是物种长期进化的结果，可以反映它们在栖息地所面临的压力。大熊猫（Ailuropoda melanoleuca）的全基因组测序表明，分布在秦岭（QIN）和非 QIN 地区的种群可能在 300 千年前就已经分化。尽管针对这些种群的觅食策略、栖息地偏好和生态位划分已经进行了许多研究，但对营养生态位的精确量化仍然缺乏。在这里，我们通过测量毛发中的碳和氮同位素，计算并比较了来自四川（SC）和 QIN 种群的大熊猫的同位素营养生态位宽度；并结合共生哺乳动物的数据，分别探讨了大熊猫在生态系统中的相对营养地位。R 中的稳定同位素贝叶斯椭圆体（SIBER）模型结果表明，QIN 大熊猫的营养生态位宽度为 3.44‰，明显大于 SC 种群（2.03‰），重叠约 1.45‰；而且它们在背景中都占据了独特的位置，几乎比食草动物低一个营养级。然后，我们确定了这些大熊猫栖息地主要食物的同位素比值；结果表明，竹笋和其他部位之间的同位素差异以及大熊猫对它们的各种摄食选择，导致了大熊猫营养生态位宽度的差异。我们认为，QIN 大熊猫的营养生态位比来自 SC 的大熊猫更宽，这是由于它们拥有更高的营养可用性和可消化的食物资源。这一结论为大熊猫的资源利用和营养生态提供了新的视角，对于制定这两个种群的精细化管理计划具有重要意义。
