Division of Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, Canberra, ACT, 0200, Australia,
Oecologia. 2014 Mar;174(3):873-82. doi: 10.1007/s00442-013-2808-3. Epub 2013 Nov 20.
Adequate nutrition is a fundamental requirement for the maintenance and growth of populations, but complex interactions between nutrients and plant toxins make it difficult to link variation in plant quality to the ecology of wild herbivores. We asked whether a 'foodscape' model of habitat that uses near-infrared spectroscopy to describe the palatability of individual trees in the landscape, predicted the foraging decisions of a mammalian browser, the koala (Phascolarctos cinereus). Specifically, we considered four behavioural decision points at which nutritional quality may influence an animal's decision. These were: which tree to enter, whether to feed from that tree, when to stop eating, and how long to remain in that tree. There were trends for koalas to feed in eucalypt trees that were more palatable than unvisited neighbouring conspecific trees, and than trees that they visited but did not eat. Koalas ate longer meals in more palatable trees, and stayed longer and spent more time feeding per visit to these trees. Using more traditional chemical analyses, we identified that an interaction between the concentrations of formylated phloroglucinol compounds (a group of plant secondary metabolites) and available N (an integrated measure of tannins, digestibility and N) influenced feeding. The study shows that foodscape models that combine spatial information with integrated measures of food quality are a powerful tool to predict the feeding behaviour of herbivores in a landscape.
充足的营养是维持和促进人口增长的基本需求，但营养物质与植物毒素之间的复杂相互作用使得将植物质量的变化与野生食草动物的生态学联系起来变得困难。我们询问了一种“食物景观”模型，该模型使用近红外光谱来描述景观中个体树木的适口性，是否可以预测一种哺乳动物食草动物——考拉（Phascolarctos cinereus）的觅食决策。具体来说，我们考虑了四个行为决策点，在这些决策点上，营养质量可能会影响动物的决策。这些决策点分别是：进入哪棵树，是否从那棵树上进食，何时停止进食，以及在那棵树上停留多长时间。考拉更倾向于在比未访问的同种邻树和它们访问但不吃的树更可口的桉树树上进食。考拉在更可口的树上吃更长时间的餐，在这些树上停留的时间更长，每次访问时花更多的时间进食。通过使用更传统的化学分析，我们发现，甲酰基间苯三酚化合物（一组植物次生代谢物）的浓度与可利用氮（单宁、消化率和氮的综合衡量指标）之间的相互作用影响了进食。这项研究表明，将空间信息与食物质量的综合衡量指标相结合的食物景观模型是预测食草动物在景观中觅食行为的有力工具。
