aye-aye (English spelling)

An animal of the Aye-aye family of the Primates order of the Mammalia class. Also known as the Ubizaru, this prosimian monkey has one family, one genus and one species. It is endemic to the island of Madagascar, and is found in the rainforests of the northeast and northwest. Its head and body length is about 40 cm, and its tail length is 50-60 cm. Its hair is a mixture of short and long bristles, and it is dark brown or black, with parts of its face and chest being whitish. It has a bushy tail, and its eyes and ears are large. Its muzzle is unique, protruding like a squirrel's, and its teeth are

They have 18 teeth. They only have one pair of incisors on each side, but they are well developed and continue to grow throughout their life. They have long fingers, the first of which on the hind legs is slightly opposable and has a flat claw, but all the others have claws. They mainly eat fruit and insect larvae. The third finger on the front legs is particularly long and flexible, which helps them to find insect larvae that live in holes under the bark. When they find a larva, they peel the bark off with their incisors and insert their finger into the tree to stir it around. They crush the larvae in this way, then repeatedly put them on their finger and quickly bring them to their mouth. They eat coconut flesh in the same way. They give birth to one child at a time, and the birth season is from October to November. They are solitary and completely nocturnal. They build spherical nests about 50 cm in diameter in the fork of a tall tree and sleep in them during the day. They were once widely distributed along the coasts of the eastern and western parts of the island, but their numbers have decreased dramatically due to deforestation and other factors. A special protected area has been established on a small island in the northeast since 1966, and plans are underway to increase the population.

[Shigeo Uehara]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

哺乳(ほにゅう)綱霊長目アイアイ科の動物。別名ユビザルともいう原猿で、1科1属1種。マダガスカル島の固有種で、北東部および北西部の多雨林に分布する。頭胴長約40センチメートル、尾長50～60センチメートル。短い毛と長い剛毛が混生し、暗褐色ないし黒色で、顔の一部と胸は白っぽい。尾はふさふさとしており、目と耳介は大きい。鼻口部が特異でリスのように突出し、歯式は

で18本。門歯は上下とも1対しかないがよく発達し、一生伸び続ける。指は長く、後肢の第1指はやや対向性を示して平(ひら)づめがあるが、ほかの指にはすべて鉤(かぎ)づめがある。おもに果実と昆虫の幼虫を食べる。前肢の第3指はとくに細長くしなやかで、樹皮下の穴にすむ昆虫の幼虫を探り出すのに役だつ。幼虫をみつけると、門歯で樹皮をはがし、この指を差し入れてかき回す。こうして幼虫をつぶし、繰り返し指につけてすばやく口に運ぶ。ココヤシの果肉も同じようにして食べる。1産1子で、出産期は10～11月。単独生活者で完全な夜行性。高い樹上の木のまたに直径約50センチメートルの球形の巣をつくり、昼間はその中で眠る。かつては同島東部と西部の海岸域に広く分布したが、森林伐採などにより激減した。1966年から北東部の小島に設けられた特別保護区で、増殖が計画されている。

［上原重男］

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