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The microbats constitute the now outdated suborder Microchiroptera within the order Chiroptera (bats). Bats were once differentiated into Megachiroptera and Microchiroptera, based on their size, but based on available molecular evidence this has now been shown to be incorrect, with the horseshoe bats being included in Yinpterochiroptera with the fruit bats and others. Most species which were termed Microchiroptera are now referred to as the Yangochiroptera. The distinctions between microbats and megabats are: * Microbats use echolocation, whereas megabats do not typically. (The Egyptian fruit bat ''Rousettus egyptiacus'' is an exception, but does not use the larynx echolocation method of microbats, instead giving scientists the theory that it clicks using its nasal passages and back of its tongue.) * Microbats lack the claw at the second finger of the forelimb. This finger appears thinner and almost bonded by tissue with the third finger for extra support during flight. * Megabats always lack a tail, whereas this trait only occurs in certain species of microbats. * The ears of microbats possess a tragus (thought to be crucial in echolocation) and are respectively larger than megabat ears, whereas megabat ears are comparatively small and lack a tragus. * Megabat eyes are quite large, whereas microbat eyes are comparatively smaller. Most microbats feed on insects. Some of the larger species hunt birds, lizards, frogs, smaller bats or even fish. The three species of microbats that feed on the blood of large mammals or birds (vampire bats) exist in the Americas south of the United States. Microbats are 4 to 16 cm long.〔Whitaker, J.O. Jr, Dannelly, H.K. & Prentice, D.A. (2004) Chitinase in insectivorous bats. Journal of. Mammalogy, 85, 15–18.〕 Leaf-nosed microbat species are not all known to be fruit and nectar-eating. Three species of leaf-nosed bats follow the bloom of columnar cacti in northwest Mexico and Southwest United States northward in the spring and then the blooming agaves southward in the fall.〔A Natural History of the Sonoran Desert, Edited by Steven Phillips and Patricia Comus, University of California Press, Berkeley p. 464〕 Yet other leaf-nosed bats, such as ''Vampyrum spectrum'' of South America, hunt a variety of prey such as lizards and birds. The horseshoe bats of Europe, though, have an incredibly intricate leaf-nose for echolocation and feed primarily on insects. Finally, the California leaf-nosed bat of North America is yet another insectivore to have this trait, as its name indicates.The term "leaf-nose," despite common fallacy, applies to a great variety of microbats and does in no way dictate the variety of diet a species with this trait prefers.〔Walker's Bats of the World, Ronald M. Nowak (1994)〕 == Echolocation == (詳細はultrasound via the larynx and emit the sound through the nose or the open mouth. Microbat range in frequency from 14,000 to over 100,000 hertz, well beyond the range of the human ear (typical human hearing range is considered to be from 20 to 20,000 Hz). The emitted vocalizations form a broad beam of sound used to probe the environment, as well as communicate with other bats. Some moths have developed a protection against bats. They are able to hear bats' ultrasounds and flee as soon as they notice these sounds, or stop beating their wings for a period of time to deprive the bats of the characteristic echo signature of moving wings on which they may home in. To counteract this, the bats may cease producing the ultrasound bursts as they near prey, and thus avoid detection. 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「microbat」の詳細全文を読む スポンサード リンク
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