Stable Isotope Ecology of Extant Tapirs from the Americas
Stable Isotope Ecology of Extant Tapirs from the Americas
复制标题
DOI：
10.1111/j.1744-7429.2011.00761.x
复制
发表时间：
2011-11-01
期刊：
影响因子：
2.1
通讯作者：
DeSantis, Larisa G.
中科院分区：
文献类型：
--
作者：
DeSantis, Larisa G.
了解现代和古代森林的生态有助于阐明森林哺乳动物的进化。然而，首先有必要阐明森林类群中稳定同位素变异的来源和程度。由于它们高度保守的饮食和栖息地偏好，它们是识别森林环境的模式生物，因此特别令人感兴趣。在这里，现存的驼鸟的稳定碳和氧同位素组成被量化，以检验关于个体发育的饮食变化、种群水平的稳定同位素变化以及稳定同位素与气候变量之间的关系的假设。一群现存的斑羚(Tapirus Bairdii)在萌出后期表现出较低的增量C-13变异(类似于2-3%)和较高的增量C-13值，这表明幼体消耗C-13耗尽牛奶和/或在茂密的森林中觅食。相反，晚萌出牙齿不同的增量O-18值反映了季节变化。现存的Tapir(T.bairdii，Tapirus pinchaque，Tapirus terrestris)三角洲O-18值受气候和地理变量的制约。最值得注意的是，贝氏毛虫的O-18值随降水频率的降低而减小。陆带绦虫通常出现在降雨量大于贝氏锥虫的地区，而增量O-18值与增量C-13值呈正相关。这些数据表明，在较潮湿的地区，它们从密度较低的树冠中蒸发较少的树叶中获得了更大比例的水分，而贝氏绒毛虫在较干燥的地区出现时，被解释为通过饮用增加了水的消耗。对现存的猿类稳定同位素生态学的了解，改善了对这些难以捉摸的哺乳动物的生态学解释，无论是现在还是过去。
Understanding the ecology of modern and ancient forests can help clarify the evolution of forest dwelling mammals. It is first necessary, however, to elucidate the source and extent of stable isotope variation in forest taxa. Tapirs are of particular interest because they are model organisms for identifying forest environments due to their highly conservative diet and habitat preferences. Here, stable carbon and oxygen isotopic compositions of extant tapirs are quantified to test hypotheses regarding ontogenetic diet shifts, stable isotope variation at the population level, and relationships between stable isotopes and climatic variables. A population of extant tapirs (Tapirus bairdii) demonstrates low delta C-13 variation (similar to 2-3%) and increased delta C-13 values in late erupting teeth, indicating that juveniles consume C-13 deplete milk and/or browse in denser forests. Disparate delta O-18 values of late erupting teeth are instead reflecting seasonal variation. Extant tapir (T. bairdii, Tapirus pinchaque, Tapirus terrestris) delta O-18 values are constrained by climatic and geographic variables. Most notably, delta O-18 values of T. bairdii decrease with decreasing precipitation frequency. Tapirus terrestris is typically present in areas with greater precipitation than T. bairdii and delta O-18 values instead positively correlate with delta C-13 values. These data indicate that tapirs in wetter areas are getting a larger proportion of their water from leaves experiencing less evaporation in denser canopies, while T. bairdii is interpreted to increase its consumption of water via drinking when present in drier areas. An understanding of extant tapir stable isotope ecology improves ecological interpretations of these elusive mammals both today and in the past.