The Asian house shrew

An Asian house shrew is seen in Bijia Mountain Park, Futian District. Photos by Isaac Cohen

The Asian house shrew

Worldwide, only a tiny percentage of all the animal species are mammals, and Shenzhen is not an exception to that proportional distribution. Although scarce and more challenging to find or observe, mammals do live around us and play a significant role in the complex dynamics of Shenzhen's ecosystems.

在全球的所有动物中，哺乳类只占了其中的极小一部分，深圳亦然。因此，想要在这座城市的野外观察到哺乳动物，并非易事。它们在隐秘的角落里默默地繁衍生息，维系着城市的生态平衡。

One unique mammal species in the city is the Asian house shrew (Suncus murinus), a small animal often confused with a tiny mouse at first sight.

亚洲家鼩便是其中一员。这种鼩鼱体型较小，常被误认为老鼠。

An Asian house shrew is seen in Bijia Mountain Park, Futian District. 

This fascinating animal has a long pointed nose, a dark grey coloration on its short velvet-like fur, and short legs and tail. They are relatively small, growing to only 15 centimeters in length, including the tail. They are swift when running for shelter or escaping a predator.

亚洲家鼩有着长而尖的鼻子，身披浓密的深灰色绒毛；体长（含尾部）仅15厘米，行动非常敏捷，在遭遇危险的时候往往能迅速逃之夭夭。

An interesting characteristic of the Asian house shrew is the presence of a large scent gland in males that creates a powerful smell used mainly to keep predators away and communicate with other individuals of their kind.

亚洲家鼩的雄性个体具有硕大的气味腺，能够散发出强烈的麝香气味。它们可以通过这种气味驱赶天敌，也可以用它和同类交流。

An Asian house shrew is seen in Bijia Mountain Park, Futian District. 

This shrew is thought to have only one mate during their reproductive periods, which can happen at any time of the year; mating can induce ovulation in females. Both parents will help collect materials and build nests, where females give birth to eight shrews per litter that will be ready to leave the nest in about three weeks.

亚洲家鼩全年可繁殖，但繁殖期配偶固定。巢穴由雌雄共同搭建，雌鼩每窝最多可产8只仔，由双亲养育3周后方可离窝独立生活。

Newborns will be ready to start a new reproductive cycle in a strikingly short 35 days, so their population could quickly go out of control if it were not for their main predator, the snake.

亚洲家鼩的亚成年个体只需35天便可性成熟，且繁殖能力极强，在没有蛇类等天敌控制种群的情况下很容易泛滥成灾。

An Asian house shrew is seen in Bijia Mountain Park, Futian District. 

House shrews are nocturnal animals mainly feeding on insects. They predate voraciously and therefore help keep insect populations under control. They are opportunistic and reportedly feed on plants too, or on any food remnants that come their way. Since these animals live in human settlements, they often feed on human food leftovers.

亚洲家鼩是一种以昆虫为食的夜行动物，食量极大，因此可以有效地控制昆虫种群的数量。它们在觅食的时候也遵循机会主义原则，只要能下肚的东西都会吃，不仅吃植物，也会在人类聚居地附近捡食剩饭剩菜。

An Asian house shrew is seen in Bijia Mountain Park, Futian District. 

House shrews are considered an invasive species, and their reproduction rates are impressive. However, they are of importance to the city’s dynamics due to their ability to control pests and insect populations. If we want to protect our ecosystems, it’s necessary to maintain a healthy proportion of all species, so that the circle of life will continue rolling, and all the species of our city will coexist in a beautiful balance the way it should be.

中国并非亚洲家鼩的原产地，但由于它们繁殖能力超群，已经在国内形成了大规模的种群。不过因为它们能够有效地控制昆虫——尤其是害虫的种群数量，所以也并非一无是处。这也启示我们，种群调控对维系生态平衡、促进生态健康循环的重要作用，唯有如此，这座城市里的物种才能继续共生共存、繁衍生息。