熊科（Ursidae）,源自拉丁语 ursus（"熊"）,意指该科的所有成员都是熊.

Ursidae, from Latin ursus (“bear”), in reference to the fact that all the members of this family are bears.

種的俗名 Common names of members

棕熊, 北極熊, 大熊貓, 美洲黑熊, 馬來熊.

Brown bears, polar bears, Giant Panda, American black bears, sun bear.

分佈 Distribution 

除南极洲和澳大利亚外的所有大陆.

All continents except Antarctica and Australia.

體型 Size

最小的物种重 25-65 公斤,长 100-140 公分,最大的重 350-700 公斤,长 2.4-3 米.

The smallest species ranges 25–65 kg in weight and 100–140 cm in length, while the largest ranges 350–700 kg and 2.4–3 m.

形態描述 Morphology

牠们用足底行走.牠们的体重主要分布在后脚上,这使牠们在行走时显得笨重.儘管牠们能够爆发出极快的速度,但很快就会感到疲倦,因此主要依靠伏击而不是追逐.牠们身上只有一种黑色素,除了毛尖有时颜色不同外,全身的毛都是一个颜色.被毛由长长的护毛和短短的密毛组成,前者形成蓬松的保护层,后者形成隔热层,将空气阻隔在皮肤附近.牠们的耳朵小而圆.犬齿很大,但主要用于炫耀,臼齿扁平、易碎.与食肉目动物中的大多数其他成员不同,黑熊的肉齿相对不发达,牠们的牙齿适应包括大量蔬菜在内的食物.

They are plantigrade (walking on the soles of the feet). They distribute their weight toward the hind feet, which makes them look lumbering when they walk. They are capable of bursts of speed but soon tire, and as a result mostly rely on ambush rather than the chase. They have a single type of melanin and the hairs have a single color throughout their length, apart from the tip which is sometimes a different shade. The coat consists of long guard hairs, which form a protective shaggy covering, and short dense hairs which form an insulating layer trapping air close to the skin. They have small rounded ears. The canine teeth are large but mostly used for display, and the molar teeth flat and crushing. Unlike most other members of the Carnivora, bears have relatively undeveloped carnassial teeth, and their teeth are adapted for a diet that includes a significant amount of vegetable matter.

生態與棲息地 Habitat & Ecology

牠们的栖息地包括热带低地雨林、针叶林和阔叶林、草原、干草原、山地草原、高山碎石坡、北极苔原,北极熊的栖息地则是浮冰.

They occur in a range of habitats which include tropical lowland rainforest, both coniferous and broadleaf forests, prairies, steppes, montane grassland, alpine scree slopes, Arctic tundra and in the case of the polar bear, ice floes.

食性 Diet

大多数熊都是机会主义杂食动物,植物摄入量多于动物摄入量,似乎是从低蛋白宏量营养素杂食动物的祖先进化而来.从树叶、树根、浆果到昆虫、腐肉、鲜肉和鱼,牠们什么都吃,消化系统和牙齿也适应这种饮食.

Most bears are opportunistic omnivores and consume more plant than animal matter, and appear to have evolved from an ancestor which was a low-protein macronutrient omnivore. They eat anything from leaves, roots, and berries to insects, carrion, fresh meat, and fish, and have digestive systems and teeth adapted to such a diet.

繁殖 Reproduction 

雌性和雄性个体只有在交配季节才有互动.牠们是多雄多雌（雄性和雌性都与多个个体交配）.牠们通常每 1-4 年生育 2 个后代.母亲负责照顾孩子.牠们大多生活在巢穴中.母亲在保护幼崽时非常凶猛.生活技能由母亲传给幼崽.

Female and male individuals only interact during mating season. They are polygynandrous (both males and females mate with multiple individuals). They usually give birth to 2 offspring every 1-4 years. Mothers are responsible for parental care. They mostly live in a den. Mothers are very aggressive when protecting the young. Live skills are passed from mother to the young.

已知的物種

Total species known

8

博物館收藏的物種

Species in the collection

4

在香港已知的物種

Species in Hong Kong

0

Reference

Nowak, R. M. (2005). Walker's Carnivores of the World. Johns Hopkins University Press.

Janis, C. M., Scott, K. M., Jacobs, L. L. (2005). Evolution of Tertiary Mammals of North America. Cambridge University Press.

Cavendish, M. (2010). Mammal Anatomy: An Illustrated Guide.

Robbins, C.T., Christian, A.L., Vineyard, T.G., Thompson, D., Knott, K. K., Tollefson, T. N., Fidgett, A. L., Wickersham, T. A. (2022). Ursids evolved early and continuously to be low-protein macronutrient omnivores. Scientific Reports volume 12, 15251. https://doi.org/10.1038/s41598-022-19742-z.