定義： The largest scale biogeographic division of the earth's surface based on the historic and evolutionary distribution patterns of plants and animals.
定義： A group of species that exploit the same food resources, and/or use the same feeding or foraging methods. http://en.wikipedia.org/wiki/Guild_(ecology)
定義： Age when primary nutritional dependency on the mother ends and independent foraging begins to make a major contribution to the offspring’s energy requirements.
