The Fenner School of Environment and Society, The Australian National University, Canberra, ACT 0200, Australia.
J Chem Ecol. 2011 Jan;37(1):71-84. doi: 10.1007/s10886-010-9889-9. Epub 2010 Dec 16.
The chemical quality of forage may determine landscape use and habitat quality for some herbivorous species. However, studies that investigate the relationship between foliar chemistry and foraging choices in wild vertebrates are rare. Petauroides volans (the greater glider) is unique among Australian marsupial folivores because it glides. It also frequently consumes foliage from both major Eucalyptus subgenera, Eucalyptus (common name "monocalypt") and Symphyomyrtus (common name "symphyomyrtle"), which differ markedly in their foliar chemistry. Such differences are thought to be a product of co-evolution that also led to guild-specific plant secondary metabolite (PSM) specialization among other marsupial eucalypt folivores. To explore whether foliar chemistry influences tree use, we analyzed foliage from eucalypt trees in which we observed P. volans during a radio tracking study and from eucalypt trees in which animals were never observed. We used a combination of chemical assays and near infrared spectrophotometry (NIRS) to determine concentrations of nitrogen (N), in vitro available nitrogen (AvailN), and in vitro digestible dry matter (DDM) from foliage sampled from the monocalypt and symphyomyrtle species, and total formylated phloroglucinol compounds (FPCs) and sideroxylonals (a class of FPCs) from the symphyomyrtle species (FPCs do not occur in monocalypts). Tree size and spatially-dependent, intraspecific variations in sideroxylonals and DDM concentrations in the symphyomyrtle foliage and of N, AvailN, and DDM in the monocalypt species were important indicators of tree use and habitat suitability for P. volans. The results i) demonstrate that guild-specific PSMs do not always lead to guild-specific foraging; ii) provide a compelling co-evolutionary case for the development of gliding in P. volans; and iii) have implications for the management and conservation of this and other folivorous species.
饲料的化学质量可能决定某些食草物种的景观利用和栖息地质量。然而，研究野生脊椎动物叶化学与觅食选择之间关系的研究很少。Petauroides volans（大滑翔者）是澳大利亚有袋目食叶动物中独一无二的，因为它会滑翔。它还经常食用来自主要桉树亚属桉树（俗称“单叶桉树”）和 Symphyomyrtus（俗称“symphyomyrtle”）的叶子，这两种叶子在叶化学上有明显的差异。这种差异被认为是协同进化的产物，也导致了其他有袋目桉树食叶动物中特定于 guild 的植物次生代谢物（PSM）的专业化。为了探讨叶化学是否影响树木的利用，我们分析了在无线电追踪研究中观察到 P. volans 的桉树树木的叶子，以及从未观察到动物的桉树树木的叶子。我们使用化学分析和近红外分光光度法（NIRS）相结合的方法，从单叶桉树和 symphyomyrtle 物种中采集的叶子中确定氮（N）、可利用氮（AvailN）和可消化干物质（DDM）的浓度，以及从 symphyomyrtle 物种中采集的总甲酰基间苯三酚化合物（FPCs）和 sideroxylonals（一类 FPCs）的浓度（FPCs 不存在于单叶桉树中）。树的大小以及 symphyomyrtle 树叶中 sideroxylonals 和 DDM 浓度的空间依赖性、种内变异，以及单叶桉树物种中 N、AvailN 和 DDM 的浓度，是 P. volans 利用树木和栖息地适宜性的重要指标。结果表明：i） guild-specific PSMs 并不总是导致 guild-specific foraging；ii）为 P. volans 滑翔能力的协同进化提供了一个令人信服的案例；iii）对这种和其他食叶物种的管理和保护具有重要意义。
