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In zoology, a nectarivore is an animal which derives its energy and nutrient requirements from a diet consisting mainly or exclusively of the sugar-rich nectar produced by flowering plants. Nectar as a food source presents a number of benefits as well as challenges. It is essentially a solution of (as much as 80%) the simple sugars sucrose, glucose and fructose, which are easily ingested and digested, representing a rich and efficient source of nutrition. This solution is often diluted either by the plant that produces it or by rain falling on a flower and many nectarivores possess adaptations to effectively rid themselves of any excess water ingested this way. However, nectar is an incomplete source of nutrition. While it does contain proteins and amino acids, these are found in low quantities, and it is severely deficient in minerals and vitamins. Very few organisms consume nectar exclusively over their whole life cycle, either supplementing it with other sources, particularly insects (thus overlapping with insectivores) or only consuming it exclusively for a set period. Many species are nectar robbers or nectar thieves, performing no pollination services to a plant while still consuming nectar. Nectar is produced by flowering plants to attract pollinators to visit the flowers and transport pollen between them. Flowers often have specialized structures that make the nectar accessible only for animals possessing appropriate morphological structures, and there are numerous examples of coevolution between nectarivores and the flowers they pollinate. For example, hummingbirds and hawkmoths have long narrow beaks that can reach nectar at the bottom of long tubular flowers. Bats, meanwhile, visit open flowers where the nectar is not as deeply hidden. ==Nectarivorous species== The majority of nectarivores are insects or birds, but instances can also be found in other animal groups. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Nectarivore」の詳細全文を読む スポンサード リンク
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