Jackal - Jackal (English spelling)

In a broad sense, it is a general term for small wolf-like species found in the Old World among animals in the genus Canis, order Carnivora, family Canidae, class Mammalia, and in a narrow sense, it refers to one of them. There are four species in this group: the golden jackal, the side-striped jackal, the black-backed jackal, and the Ximenian jackal. All of them are similar to wolves, dingoes, and Pali Ainu, but they have thin, pointed snouts and large ears. They have four pairs of papillae, one less than the other, and have ring-shaped raised areas around the bases of their molars, which makes them very similar to American coyotes. All of these above-mentioned species are primitive dog genera that appeared at the end of the Pliocene Epoch of the Tertiary Period or the beginning of the Pleistocene Epoch of the Quaternary Period, and are closely related to each other.

In the narrow sense, jackals refer to the golden jackal, Canis aureus . They are found in areas from Kenya north of Africa, the Arabian Peninsula to southeastern Europe, India, Sri Lanka, and Thailand. They have a head and body length of 60-105 cm, a tail length of 18-27 cm, and weigh 6-15 kg. Their body is reddish brown or yellowish brown, their cheeks and undersides are light colored, and the tip of their tail is black. They usually live in pairs in semi-deserts, grasslands, and open forests from lowlands to altitudes of 2,000 meters. They are mostly nocturnal, resting in bushes or holes during the day. Their food consists of small animals, ground birds, lizards, insects, fruit, and carrion left over from wild animals, but they also occasionally prey on baby antelopes and sheep. Their breeding season is irregular, and after a gestation period of 60-63 days, they give birth to 3-8 pups, and occasionally 12 pups. The young open their eyes in 10-14 days and reach sexual maturity in about 10 months. The young are usually raised by both males and females together. They live for 10-12 years in the wild.

In addition, the black-backed jackal C. mesomelas has a slightly longer tail and a black back. The tip of the tail is black. It is found in eastern and southern Africa. The side-striped jackal C. adustus has an even longer tail and limbs, a black band bordered with white on the top of its body on its side, and a white tip of its tail. It is found in Africa except for the northern part of the Sahara Desert and the southern tip. Both species have similar habits to the golden jackal. The Ximenian jackal C. simensis has a slightly different form and habits from other jackals, and mainly feeds on mice. It usually lives alone on the plateaus of Ethiopia at altitudes of 3,000 to 4,000 meters, and is also called the Ximenian fox because of its bright reddish brown fur and particularly long and slender snout. The tip of its tail is black, but the rest of its body is free of black hair.

[Yoshinori Imaizumi]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

広義には哺乳(ほにゅう)綱食肉目イヌ科イヌ属に含まれる動物のうち、旧世界に産するオオカミに似た小形種の総称で、狭義にはそのうちの1種をさす。この仲間にはキンイロジャッカル、ヨコスジジャッカル、セグロジャッカル、シメニアジャッカルの4種がある。いずれもオオカミ、ディンゴ、パリアイヌなどに似るが、吻(ふん)が細くて先がとがり、耳介が大きい。乳頭はそれらより1対少なく4対で、臼歯(きゅうし)の基部を取り巻く輪状の高まりがあり、この点でアメリカのコヨーテに酷似する。これら前記の種はすべて第三紀鮮新世末または第四紀更新世初頭に現れた原始的なイヌ属で、互いに近縁の関係にある。

　狭義のジャッカルはキンイロジャッカルCanis aureusをさす。ケニア以北のアフリカ、アラビア半島からヨーロッパ南東部、インド、スリランカ、タイまでの地域に分布し、頭胴長60～105センチメートル、尾長18～27センチメートル、体重6～15キログラム。体は赤褐色ないし黄褐色で、頬(ほお)と体下面は淡色、尾端は黒色である。普通、低地から標高2000メートルまでの半砂漠、草原、開けた森林に1対ですみ、多くは夜行性で昼間は茂みや穴の中で休む。食物は小獣、地上性の鳥、トカゲ、昆虫、果実、猛獣の食べ残した死肉などであるが、ときにはレイヨウの子、ヒツジなどを捕食する。繁殖期は不定で60～63日の妊娠ののち、3～8子、まれに12子を産む。子は10～14日で目が開き、約10か月で性的に成熟する。子は普通、雌雄が協力して育てる。寿命は野生では10～12年である。

　そのほか、セグロジャッカルC. mesomelasは、やや尾が長く背が黒い。尾端は黒色。アフリカの東部と南部に産する。ヨコスジジャッカルC. adustusはさらに尾と四肢が長く、上を白で縁どられた黒帯が体側にあり、尾端が白い。サハラ砂漠以北と南端部を除くアフリカに分布する。習性はいずれもキンイロジャッカルによく似ている。シメニアジャッカルC. simensisは、ほかのジャッカルと形態や習性がやや異なり、ネズミを主食にする。エチオピアの3000～4000メートルの高原に普通、単独ですみ、毛色が鮮やかな赤褐色で吻がとくに細長いところからシメニアギツネともよばれる。尾端は黒いが、そのほかの部分には黒毛を混じない。

［今泉吉典］

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